Move channel to shared vaclavt/sublime-chanel repo

channel.json is removed; vDiff's Package Control channel now lives
in vaclavt/sublime-chanel alongside vAI and vterm.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitattributes

@@ -0,0 +1,11 @@
+# Keep the release archive to what Sublime actually loads. Package Control
+# installs whatever the tag's zip contains, and GitHub builds that zip with
+# git archive, which honours export-ignore.
+.claude/            export-ignore
+tests/              export-ignore
+.gitattributes      export-ignore
+.gitignore          export-ignore
+diff.sublime-project export-ignore
+TODO.txt            export-ignore
+channel.json        export-ignore
+repository.json     export-ignore

.python-version

@@ -1 +1 @@
-3.8
+3.14

README.md

@@ -4,16 +4,49 @@ Review what a coding agent changed without leaving Sublime Text: the whole file,
 insertions in green, in the file's own syntax highlighting. Stage, unstage or discard the file, or jump
 to the real file at the caret's line.
 
-Install: symlink this directory into `Packages` as `vDiff` (Python 3.8 plugin host, no dependencies).
+Needs Sublime Text build 4213 or later, the build that replaced the Python 3.8 plugin host with
+Python 3.14. No dependencies.
 
-Command Palette:
+## Install with Package Control
+
+vDiff is distributed through the shared channel at
+[vaclavt/sublime-chanel](https://github.com/vaclavt/sublime-chanel), not the default one. Open
+**Preferences → Package Settings → Package Control → Settings** and put the channel URL in the
+`channels` array of the right-hand (User) pane:
+
+```json
+{
+    "channels": [
+        "https://packagecontrol.io/channel_v3.json",
+        "https://raw.githubusercontent.com/vaclavt/sublime-chanel/main/channel.json"
+    ]
+}
+```
+
+Keep `https://packagecontrol.io/channel_v3.json` in the list — dropping it hides every default
+package. Then run **Package Control: Install Package** from the Command Palette and pick **vDiff**.
+Upgrades arrive through **Package Control: Upgrade Package** like any other package.
+
+## Install from source
+
+Clone or symlink the repository into the Sublime Text `Packages` directory as `vDiff`:
+
+```bash
+git clone https://github.com/vaclavt/vdiff.git \
+  "$HOME/Library/Application Support/Sublime Text/Packages/vDiff"
+```
+
+Use one method or the other, not both: an unpacked `Packages/vDiff` directory overrides the
+`vDiff.sublime-package` that Package Control installs.
+
+## Command Palette
 
 - **vDiff: Changed Files** – uncommitted changes (staged, unstaged, untracked). Arrowing through
   the list previews each file; Enter keeps it, Esc goes back to what was shown.
 - **vDiff: Recent Commits** – last N commits, then the files of the chosen commit. A key binding to
   `vdiff_commits` with `{"sha": "HEAD"}` skips the list and reviews the last commit directly.
 
-Keys inside the review view:
+## Keys inside the review view
 
 | key | action |
 |---|---|
@@ -30,3 +63,16 @@ Keys inside the review view:
 | Esc | close the view |
 
 The header links do the same with the mouse. Settings: `vDiff.sublime-settings`.
+
+## The channel
+
+`repository.json` in this repository is a Package Control **repository** file: its top-level key
+is `packages`, and it describes vDiff itself — where the code lives and which releases exist.
+`"tags": true` means Package Control reads the repository's git tags, so publishing a release is
+just `git tag v1.0.1 && git push --tags`. A package whose tags are all unpushed resolves to zero
+releases, and Package Control drops it from the list without an error — if vDiff is missing from
+**Install Package**, check the tags reached GitHub.
+
+The channel itself — the `channels`-array file listing `repository.json` for vDiff and vaclavt's
+other packages — lives in [vaclavt/sublime-chanel](https://github.com/vaclavt/sublime-chanel), not
+here. Add a package there instead of in this repository.

TODO.txt

@@ -1,30 +1,18 @@
-macbook: claude --resume 275357c1-ce75-41de-a85a-4e06288bc8f0
 
-macstudio: claude --resume ca7e7e5d-0ad3-45e5-bd67-e5dbd3af1b4c
+## New functionality
 
+- Add (commit) summary view - in one view just changes across all files with 5 lines before and after change?)
 
-
+- Add pull and push action
-Add amend action. Similar to commit but commit --amend. When user has chosen amend open commit message input field with last commit message and cursor on the end of message and user can change commit message or confirm it by pressing Enter. When User presses Esc the commmit amend is canceled.
+- Add tags into commits list (and branches?)
-Amend action is available under key "m"
-
-
-
-- in Files in first line there is 2 staged, 2 unstaged - add there deletions and insertions
-
 - Add stash action ..
 
-- Add (commit) summary view (just changes across files with 5 lines before and after change?)
 
-- visual bell blinking time setting
+## Improvements
-
-- When reviewing changes in python files the deleted and inserted lines have red and green background but the text on these lines has no syntax highlighting (it's white on darker theme). How difficult would be to add syntax highlighting to changed lines and keep red and green background?
-(tady full syntax coloring je hard, nabizi se barevnej gutter, nebo barevne podtrzeni)
-
-- v detailu komitu when pressing n and p the second line is nonsence
-
-- add type hints
-
-- add tags into commits list (and branches?)
 
 - commit messages are oneline. What are options for multiline editing?
+- visual bell blinking time setting
+
+
+## Code
 

main.py

@@ -1,6 +1,6 @@
 """ vDiff plugin entry point: review uncommitted changes and recent commits inside Sublime Text
 
-Sublime reloads a plugin only when this file changes; after editing a submodule, save this file to reload everything.
+Sublime reloads a plugin only when this file changes, so save it after editing a submodule.
 """
 import logging
 import sys
@@ -8,7 +8,7 @@ import sys
 import sublime
 
 # sublime reloads only this file: drop the submodules so an edited one is re-imported below.
-# Open review views lose their in-memory state and are rebuilt from their settings by _restore_all.
+# Open views lose in-memory state and are rebuilt from their settings by _restore_all.
 for _name in [n for n in sys.modules if n.startswith(__package__ + ".vdiff")]:
     del sys.modules[_name]
 

repository.json

@@ -0,0 +1,21 @@
+{
+    "$schema": "sublime://packagecontrol.io/schemas/repository",
+    "schema_version": "4.0.0",
+    "packages": [
+        {
+            "name": "vDiff",
+            "details": "https://github.com/vaclavt/vdiff",
+            "description": "Review uncommitted changes and commits in Sublime Text: whole files with deletions in red and insertions in green, in the file's own syntax highlighting",
+            "author": "vaclavt",
+            "labels": ["git", "diff", "review", "vcs"],
+            "releases": [
+                {
+                    "sublime_text": ">=4213",
+                    "platforms": ["*"],
+                    "python_versions": ["3.14"],
+                    "tags": true
+                }
+            ]
+        }
+    ]
+}

tests/conftest.py

@@ -1,7 +1,25 @@
 import os
 import sys
 
+import pytest
+
 # tests import the package directly; sublime/sublime_plugin come from tests/stubs
 HERE = os.path.dirname(os.path.abspath(__file__))
 sys.path.insert(0, os.path.dirname(HERE))
 sys.path.insert(0, os.path.join(HERE, "stubs"))
+
+
+@pytest.fixture(autouse=True)
+def scheme_override_sandbox(tmp_path, monkeypatch):
+    """Keep the colour-scheme override palette.py writes inside the test's own tmp_path
+
+    Both caches are per session and every stub view shares one id, so they would otherwise leak and
+    make override assertions depend on test order.
+    """
+    import sublime
+
+    from vdiff import palette, state
+
+    palette.reset()
+    monkeypatch.setattr(state, "STATES", {})
+    monkeypatch.setattr(sublime, "packages_path", lambda: str(tmp_path))

tests/stubs/sublime.py

@@ -1,4 +1,5 @@
 """ Minimal sublime API stub so the plugin modules import and header/regions logic runs offline """
+import re
 
 OP_EQUAL = 0
 OP_NOT_EQUAL = 1
@@ -35,6 +36,10 @@ class Region:
         return f"Region({self.a}, {self.b})"
 
 
+class Edit:
+    """Opaque edit token; only ever passed through, so the annotations have something to name"""
+
+
 class Settings(dict):
     def get(self, key, default=None):
         return dict.get(self, key, default)
@@ -109,6 +114,28 @@ class Window:
         return self.input_view
 
 
+# a bundled scheme's styles: diff.* and region.* defined, the plugin's vdiff.* ones not. Nothing
+# simulates sublime merging an override, so a test wanting those to resolve adds them itself.
+DEFAULT_FG = "#ffffff"
+DEFAULT_STYLES = {
+    "diff.deleted": {"foreground": DEFAULT_FG, "background": "#4a2b2b"},
+    "diff.deleted.char": {"foreground": DEFAULT_FG, "background": "#6a3535"},
+    "diff.inserted": {"foreground": DEFAULT_FG, "background": "#2b4a3a"},
+    "diff.inserted.char": {"foreground": DEFAULT_FG, "background": "#356a4a"},
+    "region.yellowish": {"foreground": "#e6db74", "background": "#4a4a2b"},
+    "markup.deleted": {"foreground": "#d64646"},
+    "markup.inserted": {"foreground": "#46d646"},
+    # a few of palette.PALETTE_PROBES, so the palette probe finds a working set of colours
+    "source": {"foreground": DEFAULT_FG},
+    "comment": {"foreground": "#7c8595"},
+    "string": {"foreground": "#99c794"},
+    "keyword": {"foreground": "#c594c5"},
+    "constant.numeric": {"foreground": "#f99157"},
+    "entity.name.function": {"foreground": "#6699cc"},
+    "punctuation.definition": {"foreground": "#5fb3b3"},
+}
+
+
 class View:
     """Text buffer with just the calls render.py makes"""
 
@@ -125,6 +152,10 @@ class View:
         self.commands = []
         self.popup = None
         self.popup_navigate = None
+        # what style_for_scope answers; a test reshapes it to model another colour scheme
+        self.styles = {scope: dict(style) for scope, style in DEFAULT_STYLES.items()}
+        # whether sublime has merged the override vdiff writes; it only does so on a restart
+        self.override_loaded = False
 
     def id(self):
         return 1
@@ -211,8 +242,25 @@ class View:
     def em_width(self):
         return 8.0
 
+    def extract_tokens_with_scopes(self, region):
+        """One token per run of word characters and one per run of anything else, scoped by its shape
+
+        Enough for the colouring tests: real sublime returns the syntax's tokens, but the painter only
+        needs adjacent tokens to differ and each to map to a coloured scope.
+        """
+        tokens = []
+        text = self.text[region.a:region.b]
+        for match in re.finditer(r"\w+|\s+|[^\w\s]+", text):
+            scope = "keyword" if match.group().isidentifier() else "punctuation.definition"
+            tokens.append((Region(region.a + match.start(), region.a + match.end()), scope))
+        return tokens
+
     def style_for_scope(self, scope):
-        return {"foreground": "#ffffff", "background": "#333333"}
+        # a fresh dict per call, and no background for an unknown scope, like the real API
+        if self.override_loaded and scope.startswith("vdiff.") and scope not in self.styles:
+            # sublime has merged the override, so every rule vdiff wrote in it resolves
+            return {"foreground": DEFAULT_FG, "background": "#333333"}
+        return dict(self.styles.get(scope, {"foreground": DEFAULT_FG}))
 
     def is_valid(self):
         return True

tests/test_commands.py

@@ -329,8 +329,8 @@ def test_commit_items_fall_back_for_an_empty_subject():
 def loading(monkeypatch):
     """Queue run_async instead of running it inline, so a test can act mid-load like a user can
 
-    The stub runs set_timeout synchronously, which is why the real plugin's async window - the one
+    The stub runs set_timeout synchronously, so the real async window — the one n / p read stale
-    n / p used to read stale state through - is invisible to every other test in the suite.
+    state through — is invisible to every other test.
     """
     queue = []
     monkeypatch.setattr(commands, "run_async", lambda work, done: queue.append((work, done)))
@@ -522,8 +522,8 @@ def test_a_file_without_changes_neither_moves_nor_rings(rings):
 def press(monkeypatch, action, before, path, after):
     """Run `action` on `path` of `before`; git then reports `after`. Returns the paths shown
 
-    ACTIONS captured git.stage and friends when the table was built, so the subprocess is stubbed
+    ACTIONS captured git.stage and friends at build time, so the stub goes one level down at git.run,
-    one level down, at git.run; that keeps the real wiring of the action under test.
+    keeping the action's real wiring under test.
     """
     shown = []
     monkeypatch.setattr(commands.git, "run", lambda repo, args, ok_codes=(0,): "")

tests/test_palette.py

@@ -0,0 +1,86 @@
+import json
+
+import sublime  # the stub, via conftest
+
+from vdiff import palette
+
+
+def scheme_file(tmp_path):
+    """The override of whichever scheme the stub reports as active"""
+    return tmp_path / "User" / palette.override_name(sublime.View())
+
+
+def override(tmp_path):
+    """The rules palette.py wrote into that override"""
+    path = scheme_file(tmp_path)
+    return json.loads(path.read_text())["rules"] if path.exists() else None
+
+
+def by_scope(tmp_path):
+    return {rule["scope"]: rule for rule in override(tmp_path)}
+
+
+def test_a_scheme_with_diff_colours_needs_no_tint_rules(tmp_path):
+    view = sublime.View()
+    palette.ensure(view)
+
+    # the tints are the scheme's own scopes, so only the generated colour rules are ours to write
+    assert not [r for r in override(tmp_path) if r["scope"].startswith("diff.")]
+
+
+def test_a_scheme_without_diff_colours_gets_our_tints(tmp_path):
+    view = sublime.View()
+    # all or nothing per pair: taking only the half a scheme has would put our hue next to its own
+    del view.styles["diff.deleted.char"]
+    del view.styles["diff.inserted"]
+    del view.styles["diff.inserted.char"]
+    palette.ensure(view)
+
+    rules = by_scope(tmp_path)
+    assert rules[palette.SCOPE_INS]["background"] == palette.FALLBACK_TINTS[palette.SCOPE_INS]
+    assert rules[palette.SCOPE_DEL_CHAR]["background"] == palette.FALLBACK_TINTS[palette.SCOPE_DEL_CHAR]
+    # the one colour it does define is left to the scheme
+    assert palette.SCOPE_DEL not in rules
+
+
+def test_every_palette_colour_gets_a_rule_per_background_kind(tmp_path):
+    view = sublime.View()
+    palette.ensure(view)
+
+    rules = by_scope(tmp_path)
+    colours = {view.styles[scope]["foreground"] for scope in ("comment", "string", "keyword")}
+    for colour in colours:
+        scope = palette.scope_for("ins", colour)
+        assert scope is not None
+        # both properties, which is the whole point: the tint alone would flatten the text
+        assert rules[scope] == {"scope": scope, "background": view.styles["diff.inserted"]["background"],
+                                "foreground": colour}
+        for kind in palette.KINDS:
+            assert palette.scope_for(kind, colour) in rules
+
+
+def test_a_colour_the_scheme_does_not_use_has_no_scope():
+    palette.ensure(sublime.View())
+    assert palette.scope_for("ins", "#123456") is None
+
+
+def test_the_override_is_written_once_per_scheme(tmp_path):
+    view = sublime.View()
+    palette.ensure(view)
+    scheme_file(tmp_path).write_text(json.dumps({"rules": []}))
+
+    # sublime reloads the whole scheme every time we touch the file, so nothing must rewrite it
+    palette.ensure(view)
+    assert override(tmp_path) == []
+
+
+def test_a_hand_edited_override_is_never_clobbered(tmp_path):
+    (tmp_path / "User").mkdir()
+    path = tmp_path / "User" / "Mariana.sublime-color-scheme"
+    # comments are legal in a .sublime-color-scheme but decode_value here is plain json
+    path.write_text('{\n    // mine\n    "rules": []\n}')
+
+    palette.ensure(sublime.View())
+    assert "// mine" in path.read_text()
+
+

tests/test_render.py

@@ -4,7 +4,7 @@ import re
 
 import sublime  # the stub, via conftest
 
-from vdiff import commands, git, listeners, parse, render, state  # noqa: F401
+from vdiff import commands, git, listeners, palette, parse, render, state  # noqa: F401
 
 DIFF = """--- a/x.py
 +++ b/x.py
@@ -34,8 +34,17 @@ def header(view):
     return view.phantoms[render.PHANTOM_KEY][0].content
 
 
+def with_loaded_override(view):
+    """Model a view whose scheme has picked up the override palette.py writes
+
+    The stub no more simulates that merge than sublime does before a restart, so a test says so itself.
+    """
+    view.override_loaded = True
+    return view
+
+
 def test_render_text_regions_and_header():
-    view = sublime.View()
+    view = with_loaded_override(sublime.View())
     render.init_view(view)
     st = make_state()
     render.render(view, st)
@@ -200,8 +209,8 @@ def test_keymap_matches_help_table():
 def test_no_binding_yields_to_vintage_command_mode():
     """The review view is read-only, so its letters are vdiff commands in either vim mode
 
-    init_view opens the view in command mode; a binding that still carried the old
+    init_view opens in command mode; a binding still carrying the old `command_mode: false` context
-    `command_mode: false` context would go dead there, which is what broke n / p.
+    would go dead there, which is what broke n / p.
     """
     guard = {"key": "setting.command_mode", "operand": False}
     for binding in keymap_bindings():
@@ -212,8 +221,7 @@ def test_no_binding_yields_to_vintage_command_mode():
 
 
 def test_minihtml_stylesheets_reject_unsupported_selectors():
-    """minihtml drops the rest of a stylesheet at a selector it cannot parse; these are the forms
+    """minihtml drops the rest of a stylesheet at an unparsable selector; these forms broke HELP_CSS"""
-    that silently broke HELP_CSS, so no stylesheet constant may use them"""
     # descendant/child/sibling combinators, pseudo-classes, attribute selectors, compound classes
     unsupported = re.compile(r"[\s:>~+\[]|[.#][^.#]*[.#]")
     sheets = [(name, css) for name, css in vars(render).items() if name.endswith("_CSS") and isinstance(css, str)]
@@ -316,9 +324,99 @@ def test_flash_survives_a_re_render(monkeypatch):
     assert render.BELL_KEY in view.regions
 
 
-def test_bell_scope_falls_back_when_the_scheme_lacks_it(monkeypatch):
+def test_bell_scope_falls_back_when_the_scheme_lacks_it():
-    view = sublime.View()
+    view = with_loaded_override(sublime.View())
     assert render._bell_scope(view) == render.SCOPE_BELL
-    monkeypatch.setattr(view, "style_for_scope", lambda scope: {"foreground": "#fff"})
+    del view.styles["region.yellowish"]
-    # an invisible bell is a silent failure, so fall back to a scope the plugin guarantees
+    # an invisible bell is a silent failure, so fall back to a scope that is resolving
-    assert render._bell_scope(view) == render.SCOPE_INS
+    assert render._bell_scope(view) == palette.SCOPE_INS
+    # ... and when the plugin's own scopes are not resolving either, to the scheme's
+    view.override_loaded = False
+    assert render._bell_scope(view) == "diff.inserted"
+
+
+def token_regions(view, kind, colour):
+    """The regions painted for one (background kind, colour) pair of the token layer"""
+    scope = palette.scope_for(kind, colour)
+    entry = view.regions.get(scope and scope.replace("vdiff.", "vdiff.tok.", 1))
+    return entry[0] if entry else []
+
+
+def test_changed_lines_are_repainted_in_the_files_own_colours():
+    view = with_loaded_override(sublime.View())
+    render.init_view(view)
+    render.render(view, make_state())
+
+    keyword = view.styles["keyword"]["foreground"]
+    punctuation = view.styles["punctuation.definition"]["foreground"]
+    # "    return 10" is inserted: its words carry the keyword colour, its spaces and digits their
+    # own runs. Without this layer all of them would be the tint's flat foreground.
+    inserted = token_regions(view, "ins", keyword)
+    assert sublime.Region(view.text_point(4, 4), view.text_point(4, 10)) in inserted
+    # and a deleted line is painted from the deleted palette, not the inserted one
+    assert sublime.Region(view.text_point(2, 4), view.text_point(2, 10)) in token_regions(view, "del", keyword)
+    assert token_regions(view, "del", punctuation)
+
+    # the plain tint still covers the whole line underneath, so gaps and line ends stay coloured
+    assert view.regions[render.KEY_INS][1] == palette.SCOPE_INS
+
+
+def test_token_runs_merge_but_stop_at_a_word_diff_range():
+    view = with_loaded_override(sublime.View())
+    render.init_view(view)
+    render.render(view, make_state("--- a/y\n+++ b/y\n@@ -1 +1 @@\n-foo = bar\n+foo = baz\n"))
+
+    keyword = view.styles["keyword"]["foreground"]
+    # only the changed character sits in the stronger tint; the rest of the word keeps the line tint
+    assert token_regions(view, "ins.char", keyword) == [sublime.Region(view.text_point(2, 8), view.text_point(2, 9))]
+    plain = token_regions(view, "ins", keyword)
+    assert sublime.Region(view.text_point(2, 6), view.text_point(2, 8)) in plain
+    assert sublime.Region(view.text_point(2, 0), view.text_point(2, 3)) in plain
+
+
+def test_token_layer_waits_for_the_scopes_to_resolve():
+    view = sublime.View()
+    render.init_view(view)
+    render.render(view, make_state())
+
+    # the override is not loaded yet, so the lines keep the flat tint and no token key is painted:
+    # an unknown scope would draw its text in sublime's marker green
+    assert view.regions[render.KEY_DEL][1] == "diff.deleted"
+    assert view.regions[render.KEY_INS][1] == "diff.inserted"
+    assert not [key for key in view.regions if key.startswith("vdiff.tok.")]
+
+
+def test_token_layer_is_skipped_for_a_diff_too_big_to_read(monkeypatch):
+    monkeypatch.setattr(render, "TOKEN_COLOUR_MAX_CHARS", 4)
+    view = with_loaded_override(sublime.View())
+    render.init_view(view)
+    render.render(view, make_state())
+
+    assert not [key for key in view.regions if key.startswith("vdiff.tok.")]
+
+
+def test_token_regions_are_dropped_when_a_re_render_no_longer_needs_them():
+    view = with_loaded_override(sublime.View())
+    render.init_view(view)
+    render.render(view, make_state())
+    assert [key for key in view.regions if key.startswith("vdiff.tok.")]
+
+    render.render(view, make_state("--- a/y\n+++ b/y\n@@ -1,2 +1,2 @@\n a\n-b\n+c\n"))
+    keyword = view.styles["keyword"]["foreground"]
+    # the new diff paints far fewer runs; the keys the old one used must not linger
+    assert token_regions(view, "ins", keyword) == [sublime.Region(view.text_point(3, 0), view.text_point(3, 1))]
+
+
+def test_restart_notice_when_the_override_cannot_take_effect_yet(monkeypatch):
+    said = []
+    monkeypatch.setattr(sublime, "status_message", said.append)
+    view = sublime.View()
+    render.init_view(view)
+    render.render(view, make_state())
+
+    assert said == ["vDiff: " + render.NEEDS_RESTART]
+    # said once per scheme, not once per render
+    render.render(view, make_state())
+    assert said == ["vDiff: " + render.NEEDS_RESTART]
+
+

vdiff/commands.py

@@ -1,15 +1,21 @@
 """ Commands: the two quick panels (changed files, recent commits) and the actions of a review view """
 import bisect
 import os
+from typing import Callable, Dict, List, Optional, Sequence, Tuple
 
 import sublime
 import sublime_plugin
 
 from . import git, parse, render, state
+from .git import Commit, FileChange
+from .state import Kept, ViewState
 from .utils import file_count, run_async, settings, status
 
+# what an ACTIONS entry does: act(view, window, state) for the review view it was fired in
+Action = Callable[[sublime.View, sublime.Window, ViewState], None]
+
 # quick-panel kind per status letter: colour + the letter; the description comes from git.STATUS_NAMES
-STATUS_COLOURS = {
+STATUS_COLOURS: Dict[str, int] = {
     "M": sublime.KIND_ID_COLOR_ORANGISH,
     "A": sublime.KIND_ID_COLOR_GREENISH,
     "?": sublime.KIND_ID_COLOR_GREENISH,
@@ -21,8 +27,8 @@ STATUS_COLOURS = {
 }
 COMMIT_KIND = (sublime.KIND_ID_COLOR_BLUISH, "c", "commit")
 
-# a quick-panel row draws the annotation hard right on the subject's line; past this budget the
+# the annotation is drawn hard right of the subject, so past this budget the subject is clipped.
-# subject would run into it, so it is clipped. The floor keeps a readable stub on a narrow panel.
+# The floor keeps a readable stub on a narrow panel.
 COMMIT_ROW_WIDTH = 120
 MIN_SUBJECT_WIDTH = 24
 
@@ -30,20 +36,22 @@ MIN_SUBJECT_WIDTH = 24
 PREVIEW_DELAY_MS = 60
 
 # directory -> repository root; roots do not move, and resolving runs on the UI thread
-_roots = {}
+_roots: Dict[str, str] = {}
 
 
-def resolve_repo(window):
+def resolve_repo(window: sublime.Window) -> Optional[str]:
     """Repository of the review view or active file, else of the first project folder that is one"""
     view = window.active_view()
-    candidates = []
+    candidates: List[str] = []
     if view is not None:
         if state.is_review_view(view):
             st = state.get(view) or restore_view(view)
             if st.repo:
                 return st.repo
-        elif view.file_name():
+        else:
-            candidates.append(os.path.dirname(view.file_name()))
+            name = view.file_name()
+            if name:
+                candidates.append(os.path.dirname(name))
     candidates.extend(window.folders())
     for directory in candidates:
         root = _roots.get(directory)
@@ -56,14 +64,14 @@ def resolve_repo(window):
     return None
 
 
-def find_review_view(window):
+def find_review_view(window: sublime.Window) -> Optional[sublime.View]:
     for view in window.views():
         if state.is_review_view(view):
             return view
     return None
 
 
-def open_review(window):
+def open_review(window: sublime.Window) -> Optional[Tuple[sublime.View, ViewState]]:
     """(view, state) of the window's single review view for the resolved repo, focused; None without a repo"""
     repo = resolve_repo(window)
     if not repo:
@@ -81,7 +89,7 @@ def open_review(window):
     return view, st
 
 
-def show_file(view, st, change):
+def show_file(view: sublime.View, st: ViewState, change: FileChange) -> None:
     """Fetch and parse the file's diff on the worker thread, then render it"""
     st.token += 1
     # set before the worker starts: n / p count from here while the diff is still loading
@@ -89,14 +97,14 @@ def show_file(view, st, change):
     token = st.token
     repo, sha = st.repo, st.sha
 
-    def work():
+    def work() -> Optional[Tuple[parse.Diff, List[parse.Block]]]:
         if token != st.token:
             return None  # superseded before it started: skip the subprocess
         text = git.full_diff(repo, change.path, sha=sha, untracked=(change.status == "?"))
         diff = parse.parse_unified(text)
         return diff, parse.change_blocks(diff.lines)
 
-    def done(result):
+    def done(result: Optional[Tuple[parse.Diff, List[parse.Block]]]) -> None:
         if result is None or token != st.token or not view.is_valid():
             return
         diff, blocks = result
@@ -108,8 +116,8 @@ def show_file(view, st, change):
     run_async(work, done)
 
 
-def file_items(files):
+def file_items(files: Sequence[FileChange]) -> List[sublime.QuickPanelItem]:
-    items = []
+    items: List[sublime.QuickPanelItem] = []
     for change in files:
         description = git.STATUS_NAMES.get(change.status, "")
         colour = STATUS_COLOURS.get(change.status)
@@ -125,9 +133,9 @@ def file_items(files):
     return items
 
 
-def commit_items(commits):
+def commit_items(commits: Sequence[Commit]) -> List[sublime.QuickPanelItem]:
     """Quick-panel rows: subject on the left, its totals and the hash right-aligned"""
-    items = []
+    items: List[sublime.QuickPanelItem] = []
     for c in commits:
         annotation = c.short
         if c.files is not None:
@@ -141,13 +149,15 @@ def commit_items(commits):
     return items
 
 
-def show_files_panel(window, view, st, files, kept, on_cancel=None, placeholder="Changed files"):
+def show_files_panel(window: sublime.Window, view: sublime.View, st: ViewState, files: List[FileChange],
+                     kept: Kept, on_cancel: Optional[Callable[[], None]] = None,
+                     placeholder: str = "Changed files") -> None:
     """Quick panel over `files`; highlighting previews, Enter keeps, Esc restores `kept` (or runs on_cancel)"""
     st.files = files
     selected = max(0, st.index())
     window.focus_view(view)
 
-    def on_select(index):
+    def on_select(index: int) -> None:
         st.highlight += 1  # cancel a pending preview
         if index == -1:
             if on_cancel is not None:
@@ -164,28 +174,33 @@ def show_files_panel(window, view, st, files, kept, on_cancel=None, placeholder=
             return  # the preview already shows it
         show_file(view, st, change)
 
-    def on_highlight(index):
+    def on_highlight(index: int) -> None:
         if not 0 <= index < len(files):
             return
         st.highlight += 1
         ticket = st.highlight
-        sublime.set_timeout(lambda: ticket == st.highlight and show_file(view, st, files[index]), PREVIEW_DELAY_MS)
+
+        def preview() -> None:
+            if ticket == st.highlight:
+                show_file(view, st, files[index])
+
+        sublime.set_timeout(preview, PREVIEW_DELAY_MS)
 
     window.show_quick_panel(file_items(files), on_select, 0, selected, on_highlight, placeholder)
 
 
-def refresh_listing(view, st, message=None, pick=None):
+def refresh_listing(view: sublime.View, st: ViewState, message: Optional[str] = None,
+                    pick: Optional[Callable[[List[FileChange], int], Optional[FileChange]]] = None) -> None:
     """Re-list the working tree changes and show the same file, or the next one when it is gone
 
-    `pick(files, index)` may name another file to show instead; `index` is where the shown file
+    `pick(files, index)` may name another file instead; `index` is the shown file's slot, new or vacated.
-    sits in the new list, or the slot it left behind when it is gone.
     """
     if message:
         status(message)
     previous_index = max(0, st.index())
     path = st.change.path if st.change else None
 
-    def done(files):
+    def done(files: List[FileChange]) -> None:
         if not view.is_valid():
             return
         st.files = files
@@ -202,7 +217,7 @@ def refresh_listing(view, st, message=None, pick=None):
     run_async(lambda: git.changed_files(st.repo), done)
 
 
-def refresh_if_changed(view, st):
+def refresh_if_changed(view: sublime.View, st: ViewState) -> None:
     """Re-render a working-tree view when the file or the index changed since it was drawn"""
     if st.in_commit or st.change is None:
         return
@@ -213,14 +228,14 @@ def refresh_if_changed(view, st):
 class VdiffFilesCommand(sublime_plugin.WindowCommand):
     """List uncommitted changes (staged, unstaged, untracked) in a quick panel"""
 
-    def run(self):
+    def run(self) -> None:
         window = self.window
         opened = open_review(window)
         if not opened:
             return
         view, st = opened
 
-        def done(files):
+        def done(files: List[FileChange]) -> None:
             if not view.is_valid():
                 return
             kept = st.enter()
@@ -237,7 +252,7 @@ class VdiffFilesCommand(sublime_plugin.WindowCommand):
 class VdiffCommitsCommand(sublime_plugin.WindowCommand):
     """List recent commits, then the files of the chosen commit; `sha` skips straight to one commit"""
 
-    def run(self, selected=0, sha=None):
+    def run(self, selected: int = 0, sha: Optional[str] = None) -> None:
         opened = open_review(self.window)
         if not opened:
             return
@@ -247,7 +262,7 @@ class VdiffCommitsCommand(sublime_plugin.WindowCommand):
             return
         count = int(settings().get("commits_count", 30) or 30)
 
-        def done(commits):
+        def done(commits: List[Commit]) -> None:
             if not view.is_valid():
                 return
             if not commits:
@@ -257,23 +272,23 @@ class VdiffCommitsCommand(sublime_plugin.WindowCommand):
 
         run_async(lambda: git.recent_commits(st.repo, count), done)
 
-    def show_commits(self, view, st, commits, selected):
+    def show_commits(self, view: sublime.View, st: ViewState, commits: Sequence[Commit], selected: int) -> None:
         items = commit_items(commits)
         for i, c in enumerate(commits):
             if c.sha == st.sha:
                 selected = i
 
-        def on_select(index):
+        def on_select(index: int) -> None:
             if index != -1:
                 self.open_commit(view, st, commits[index].sha, index)
 
         self.window.show_quick_panel(items, on_select, 0, selected, None, "Recent commits")
 
-    def open_commit(self, view, st, sha, index):
+    def open_commit(self, view: sublime.View, st: ViewState, sha: str, index: Optional[int]) -> None:
         """Files panel of one commit; Esc goes back to the commit list when it came from there (index given)"""
         window = self.window
 
-        def done(result):
+        def done(result: Tuple[git.CommitInfo, List[FileChange]]) -> None:
             if not view.is_valid():
                 return
             info, files = result
@@ -282,7 +297,7 @@ class VdiffCommitsCommand(sublime_plugin.WindowCommand):
                 render.render_message(view, st, f"Commit {info.short} touches no files")
                 return
 
-            def back():
+            def back() -> None:
                 window.run_command("vdiff_commits", {"selected": index})
 
             placeholder = f"{info.short} · {info.subject}"
@@ -295,29 +310,28 @@ class VdiffCommitsCommand(sublime_plugin.WindowCommand):
 # --- review view actions ----------------------------------------------------
 
 
-def _act_files(view, window, st):
+def _act_files(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     window.run_command("vdiff_files")
 
 
-def _act_commits(view, window, st):
+def _act_commits(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     window.run_command("vdiff_commits")
 
 
-def _act_close(view, window, st):
+def _act_close(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     view.close()
 
 
-def _act_help(view, window, st):
+def _act_help(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     render.show_help(view, st)
 
 
-def _git_action(verb, done_verb, operation, confirm=None, pick=None):
+def _git_action(verb: str, done_verb: str, operation: Callable[[str, FileChange], None],
-    """Action running `operation(repo, change)` on the shown working-tree file, then re-listing
+                confirm: Optional[Callable[[FileChange], bool]] = None,
+                pick: Optional[Callable[[List[FileChange], int], Optional[FileChange]]] = None) -> Action:
+    """Run `operation(repo, change)` on the shown working-tree file, then re-list; `pick` goes to refresh_listing"""
 
-    `pick` is handed to refresh_listing to choose which file to show afterwards.
+    def act(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
-    """
-
-    def act(view, window, st):
         if st.in_commit or st.change is None:
             status(f"{verb} works on uncommitted changes only")
             return
@@ -332,7 +346,7 @@ def _git_action(verb, done_verb, operation, confirm=None, pick=None):
     return act
 
 
-def _confirm_discard(change):
+def _confirm_discard(change: FileChange) -> bool:
     if not settings().get("confirm_discard", True):
         return True
     if change.status == "?":
@@ -345,7 +359,7 @@ def _confirm_discard(change):
     return sublime.ok_cancel_dialog(message, "Discard")
 
 
-def _next_unstaged(files, start):
+def _next_unstaged(files: Sequence[FileChange], start: int) -> int:
     """Index of the first unstaged file from `start` on, wrapping round; -1 when every file is staged"""
     for offset in range(len(files)):
         index = (start + offset) % len(files)
@@ -354,7 +368,7 @@ def _next_unstaged(files, start):
     return -1
 
 
-def _stage_next(files, index):
+def _stage_next(files: Sequence[FileChange], index: int) -> Optional[FileChange]:
     """After staging, the next unstaged file to show; None keeps the file the refresh would show"""
     if not settings().get("stage_and_move_next_file", True):
         return None
@@ -363,7 +377,7 @@ def _stage_next(files, index):
     return files[following] if following >= 0 else None
 
 
-def _act_refresh(view, window, st):
+def _act_refresh(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     if st.change is None:
         return
     if st.in_commit:
@@ -372,7 +386,7 @@ def _act_refresh(view, window, st):
         refresh_listing(view, st)
 
 
-def _act_open(view, window, st):
+def _act_open(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     if st.change is None:
         return
     path = os.path.join(st.repo, st.change.path)
@@ -383,8 +397,8 @@ def _act_open(view, window, st):
     window.open_file(f"{path}:{line}", sublime.ENCODED_POSITION)
 
 
-def _step_file(delta):
+def _step_file(delta: int) -> Action:
-    def act(view, window, st):
+    def act(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
         if not st.files:
             status("no file list, press f or c")
             return
@@ -406,8 +420,8 @@ def _step_file(delta):
     return act
 
 
-def _step_change(delta):
+def _step_change(delta: int) -> Action:
-    def act(view, window, st):
+    def act(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
         starts = [start for start, _ in st.blocks]
         if not starts:
             status("no changes to step through")
@@ -425,7 +439,7 @@ def _step_change(delta):
     return act
 
 
-def _act_commit(view, window, st):
+def _act_commit(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     """Commit the staged files with a message typed into an input panel; Esc there cancels"""
     if st.in_commit:
         status("commit works on uncommitted changes only")
@@ -435,7 +449,7 @@ def _act_commit(view, window, st):
         status("no staged files")
         return
 
-    def on_done(message):
+    def on_done(message: str) -> None:
         if not message.strip():
             status("commit cancelled: empty message")
             return
@@ -447,21 +461,20 @@ def _act_commit(view, window, st):
     window.show_input_panel("Commit message", "", on_done, None, None)
 
 
-def _act_amend(view, window, st):
+def _act_amend(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
     """Rewrite HEAD's message in an input panel, folding in whatever is staged; Esc there cancels
 
-    The panel is one line, so only the subject is offered; the rest of the message rides along
+    The one-line panel offers only the subject; the body rides along verbatim, and nothing staged is a reword.
-    verbatim. Nothing staged is fine - then the amend is a pure reword.
     """
     if st.in_commit:
         status("amend works on uncommitted changes only")
         return
     staged = [c for c in st.files if c.staged]
 
-    def prompt(message):
+    def prompt(message: str) -> None:
         subject, newline, body = message.partition("\n")
 
-        def on_done(text):
+        def on_done(text: str) -> None:
             if not text.strip():
                 status("amend cancelled: empty message")
                 return
@@ -482,14 +495,14 @@ def _act_amend(view, window, st):
     run_async(lambda: git.head_message(st.repo), prompt)
 
 
-def _move_line(forward):
+def _move_line(forward: bool) -> Action:
-    def act(view, window, st):
+    def act(view: sublime.View, window: sublime.Window, st: ViewState) -> None:
         view.run_command("move", {"by": "lines", "forward": forward})
 
     return act
 
 
-ACTIONS = {
+ACTIONS: Dict[str, Action] = {
     "files": _act_files,
     "commits": _act_commits,
     "close": _act_close,
@@ -513,10 +526,10 @@ ACTIONS = {
 class VdiffActionCommand(sublime_plugin.TextCommand):
     """Every key/link action of a review view, dispatched by name through ACTIONS"""
 
-    def is_enabled(self, action=None):
+    def is_enabled(self, action: Optional[str] = None) -> bool:
         return state.is_review_view(self.view)
 
-    def run(self, edit, action):
+    def run(self, edit: sublime.Edit, action: str) -> None:
         act = ACTIONS.get(action)
         if act is None:
             status(f"unknown action {action}")
@@ -525,7 +538,7 @@ class VdiffActionCommand(sublime_plugin.TextCommand):
         act(self.view, self.view.window(), st)
 
 
-def restore_view(view):
+def restore_view(view: sublime.View) -> ViewState:
     """Rebuild the state of a review view restored from a previous session; re-renders asynchronously"""
     data = view.settings().get(state.VIEW_DATA) or {}
     repo = data.get("repo")
@@ -542,16 +555,17 @@ def restore_view(view):
         return st
     change = git.FileChange(path, data.get("status", "M"), bool(data.get("staged")), None, None, None)
 
-    if st.in_commit:
+    sha = st.sha
+    if sha is not None:
 
-        def done(result):
+        def show_commit(result: Tuple[git.CommitInfo, List[FileChange]]) -> None:
             st.commit, st.files = result
             show_file(view, st, change)
 
-        run_async(lambda: git.commit_with_files(repo, st.sha), done)
+        run_async(lambda: git.commit_with_files(repo, sha), show_commit)
     else:
 
-        def done(files):
+        def show_working_tree(files: List[FileChange]) -> None:
             st.files = files
             index = state.find_change(files, path)
             if index >= 0:
@@ -559,5 +573,5 @@ def restore_view(view):
             else:
                 render.render_message(view, st, f"{path} has no uncommitted changes any more")
 
-        run_async(lambda: git.changed_files(repo), done)
+        run_async(lambda: git.changed_files(repo), show_working_tree)
     return st

vdiff/git.py

@@ -2,13 +2,44 @@
 import os
 import re
 import subprocess
-from collections import namedtuple
+from typing import Dict, List, Optional, NamedTuple, Sequence, Tuple
 
-# path, one-letter status (M A D R ?), staged flag, numstat counts (None for binary), rename source
+
-FileChange = namedtuple("FileChange", "path status staged insertions deletions old_path")
+class FileChange(NamedTuple):
-# shortstat totals; all three are None when git prints no diffstat (merges, empty commits)
+    """path, one-letter status (M A D R ?), staged flag, numstat counts (None for binary), rename source"""
-Commit = namedtuple("Commit", "sha short author date subject files insertions deletions")
+
-CommitInfo = namedtuple("CommitInfo", "sha short author date subject body")
+    path: str
+    status: str
+    staged: bool
+    insertions: Optional[int]
+    deletions: Optional[int]
+    old_path: Optional[str]
+
+
+class Commit(NamedTuple):
+    """shortstat totals; all three are None when git prints no diffstat (merges, empty commits)"""
+
+    sha: str
+    short: str
+    author: str
+    date: str
+    subject: str
+    files: Optional[int]
+    insertions: Optional[int]
+    deletions: Optional[int]
+
+
+class CommitInfo(NamedTuple):
+    sha: str
+    short: str
+    author: str
+    date: str
+    subject: str
+    body: str
+
+
+# a numstat entry: insertions, deletions (both None for a binary file) and the rename source
+Numstat = Tuple[Optional[int], Optional[int], Optional[str]]
 
 # hash of the empty tree: the diff base for a repository without commits
 EMPTY_TREE = "4b825dc642cb6eb9a060e54bf8d69288fbee4904"
@@ -17,9 +48,9 @@ EMPTY_TREE = "4b825dc642cb6eb9a060e54bf8d69288fbee4904"
 FULL_CONTEXT = "-U999999"
 
 # overridable from settings (sublime's PATH may not have a user-installed git)
-GIT_BINARY = "git"
+GIT_BINARY: str = "git"
 
-STATUS_NAMES = {
+STATUS_NAMES: Dict[str, str] = {
     "M": "modified",
     "A": "added",
     "D": "deleted",
@@ -40,14 +71,14 @@ _SHORTSTAT = re.compile(r"\s*(\d+) files? changed(?:, (\d+) insertions?\(\+\))?(
 class GitError(Exception):
     """git exited with an unexpected code; str() is the first stderr line, `stderr` the whole of it"""
 
-    def __init__(self, stderr, code):
+    def __init__(self, stderr: str, code: int) -> None:
         self.stderr = stderr
         self.code = code
         first = stderr.strip().splitlines()
         super().__init__(first[0] if first else f"git exited with {code}")
 
 
-def run(repo, args, ok_codes=(0,)):
+def run(repo: str, args: Sequence[str], ok_codes: Tuple[int, ...] = (0,)) -> str:
     """Run git in `repo`, return stdout as text"""
     cmd = [GIT_BINARY, "-c", "core.quotepath=off", "--no-pager"] + list(args)
     proc = subprocess.run(cmd, cwd=repo, stdout=subprocess.PIPE, stderr=subprocess.PIPE, encoding="utf-8", errors="replace")
@@ -56,7 +87,7 @@ def run(repo, args, ok_codes=(0,)):
     return proc.stdout
 
 
-def repo_root(path):
+def repo_root(path: Optional[str]) -> Optional[str]:
     """Top-level directory of the repository containing `path`, or None"""
     if not path:
         return None
@@ -70,7 +101,7 @@ def repo_root(path):
     return root or None
 
 
-def has_head(repo):
+def has_head(repo: str) -> bool:
     """False in a repository without commits"""
     try:
         run(repo, ["rev-parse", "--verify", "-q", "HEAD"])
@@ -79,19 +110,19 @@ def has_head(repo):
         return False
 
 
-def base_ref(repo):
+def base_ref(repo: str) -> str:
     """HEAD, or the empty tree when there is no commit yet"""
     return "HEAD" if has_head(repo) else EMPTY_TREE
 
 
-def _int_or_none(value):
+def _int_or_none(value: str) -> Optional[int]:
     """A numstat count: "-" marks a binary file"""
     return None if value == "-" else int(value)
 
 
-def _parse_numstat(text):
+def _parse_numstat(text: str) -> Dict[str, Numstat]:
     """`--numstat -z` output -> {path: (insertions, deletions, old_path)}"""
-    result = {}
+    result: Dict[str, Numstat] = {}
     fields = iter(text.split("\0"))
     for entry in fields:
         parts = entry.split("\t")
@@ -107,9 +138,9 @@ def _parse_numstat(text):
     return result
 
 
-def _parse_name_status(text):
+def _parse_name_status(text: str) -> List[Tuple[str, str, Optional[str]]]:
     """`--name-status -z` output -> [(status letter, path, old_path)]"""
-    result = []
+    result: List[Tuple[str, str, Optional[str]]] = []
     fields = iter(text.split("\0"))
     for status in fields:
         if not status:
@@ -122,7 +153,7 @@ def _parse_name_status(text):
     return result
 
 
-def _count_lines(path):
+def _count_lines(path: str) -> Optional[int]:
     """Line count of a working-tree file, None when binary or unreadable"""
     try:
         with open(path, "rb") as f:
@@ -144,7 +175,7 @@ def _count_lines(path):
     return count + (0 if last == b"\n" else 1)
 
 
-def changed_files(repo):
+def changed_files(repo: str) -> List[FileChange]:
     """Working tree changes vs HEAD: staged, unstaged and untracked, sorted by path"""
     status = run(repo, ["status", "--porcelain=v2", "-z", "--branch", "--untracked-files=all", "--no-renames"])
     entries = [e for e in status.split("\0") if e]
@@ -152,7 +183,7 @@ def changed_files(repo):
     base = EMPTY_TREE if "# branch.oid (initial)" in entries else "HEAD"
     counts = _parse_numstat(run(repo, ["diff", "--numstat", "-z", "--no-renames", base]))
 
-    changes = []
+    changes: List[FileChange] = []
     for entry in entries:
         kind = entry[0]
         if kind == "1":
@@ -177,26 +208,28 @@ def changed_files(repo):
     return changes
 
 
-def recent_commits(repo, count):
+def recent_commits(repo: str, count: int) -> List[Commit]:
     """Last `count` commits, newest first; empty list without commits"""
     if not has_head(repo):
         return []
     # --shortstat rides along on the same call: one subprocess, totals for free
     text = run(repo, ["log", "-n", str(count), "--format=%H%x1f%h%x1f%an%x1f%ar%x1f%s", "--shortstat"])
-    commits = []
+    commits: List[Commit] = []
     for line in text.split("\n"):
         parts = line.split("\x1f")
         if len(parts) == 5:
-            commits.append(Commit(*parts, files=None, insertions=None, deletions=None))
+            sha, short, author, date, subject = parts
+            commits.append(Commit(sha, short, author, date, subject, files=None, insertions=None, deletions=None))
             continue
-        stat = commits and commits[-1].files is None and _SHORTSTAT.match(line)
+        if commits and commits[-1].files is None:
-        if stat:
+            stat = _SHORTSTAT.match(line)
-            files, ins, dele = (int(g or 0) for g in stat.groups())
+            if stat:
-            commits[-1] = commits[-1]._replace(files=files, insertions=ins, deletions=dele)
+                files, ins, dele = (int(g or 0) for g in stat.groups())
+                commits[-1] = commits[-1]._replace(files=files, insertions=ins, deletions=dele)
     return commits
 
 
-def commit_with_files(repo, sha):
+def commit_with_files(repo: str, sha: str) -> Tuple[CommitInfo, List[FileChange]]:
     """(CommitInfo, [FileChange]) of one commit vs its first parent, files sorted by path; two git calls"""
     show = ["show", "--first-parent", "-m", "-z"]
     text = run(repo, show + [f"--format={_INFO_FORMAT}%x00", _DATE_FORMAT, "--name-status", sha])
@@ -209,7 +242,7 @@ def commit_with_files(repo, sha):
     info = CommitInfo(*parts[:6])
 
     counts = _parse_numstat(run(repo, show + ["--format=", "--numstat", sha]))
-    changes = []
+    changes: List[FileChange] = []
     for status, path, old_path in _parse_name_status(files_text):
         ins, dele, _ = counts.get(path, (None, None, None))
         changes.append(FileChange(path, status, False, ins, dele, old_path))
@@ -217,7 +250,7 @@ def commit_with_files(repo, sha):
     return info, changes
 
 
-def _in_tree(repo, ref, path):
+def _in_tree(repo: str, ref: str, path: str) -> bool:
     """Whether `path` exists in the tree of `ref`"""
     try:
         run(repo, ["cat-file", "-e", f"{ref}:{path}"])
@@ -226,11 +259,11 @@ def _in_tree(repo, ref, path):
         return False
 
 
-def full_diff(repo, path, sha=None, untracked=False):
+def full_diff(repo: str, path: str, sha: Optional[str] = None, untracked: bool = False) -> str:
     """Unified diff of one file with the whole file as context
 
-    Working tree vs HEAD (staged and unstaged merged) by default; a commit vs its
+    Working tree vs HEAD by default (staged and unstaged merged), a commit vs its first parent with
-    first parent when `sha` is given; the whole file as insertions when untracked.
+    `sha`, the whole file as insertions when untracked.
     """
     common = ["--no-color", "--no-ext-diff", FULL_CONTEXT]
     if untracked:
@@ -240,31 +273,30 @@ def full_diff(repo, path, sha=None, untracked=False):
     return run(repo, ["diff"] + common + [base_ref(repo), "--", path])
 
 
-def stage(repo, change):
+def stage(repo: str, change: FileChange) -> None:
     """Stage the whole file, including its deletion"""
     run(repo, ["add", "-A", "--", change.path])
 
 
-def commit(repo, message):
+def commit(repo: str, message: str) -> None:
     """Commit what is staged; the message is one argv element, so it needs no quoting of its own"""
     run(repo, ["commit", "-m", message])
 
 
-def head_message(repo):
+def head_message(repo: str) -> str:
     """HEAD's whole message, exactly as git stores it"""
     return run(repo, ["log", "-1", "--format=%B"]).strip("\n")
 
 
-def amend(repo, message, allow_empty=False):
+def amend(repo: str, message: str, allow_empty: bool = False) -> None:
     """Rewrite HEAD with `message`, folding in whatever is staged
 
-    `allow_empty` for a pure reword: git otherwise refuses an amend whose result carries no change,
+    `allow_empty` for a pure reword: git refuses an amend carrying no change, failing on an empty commit.
-    which would fail on a commit that happens to be empty.
     """
     run(repo, ["commit", "--amend"] + (["--allow-empty"] if allow_empty else []) + ["-m", message])
 
 
-def unstage(repo, change):
+def unstage(repo: str, change: FileChange) -> None:
     """Move the file's staged changes back to the working tree"""
     if has_head(repo):
         run(repo, ["reset", "-q", "--", change.path])
@@ -272,7 +304,7 @@ def unstage(repo, change):
         run(repo, ["rm", "-r", "-q", "--cached", "--", change.path])
 
 
-def discard(repo, change):
+def discard(repo: str, change: FileChange) -> None:
     """Throw away the file's changes, staged and unstaged, restoring the HEAD version"""
     if change.status == "?":
         run(repo, ["clean", "-f", "--", change.path])

vdiff/listeners.py

@@ -7,15 +7,15 @@ from .commands import refresh_if_changed, restore_view
 
 
 class VdiffEventListener(sublime_plugin.EventListener):
-    def on_pre_close(self, view):
+    def on_pre_close(self, view: sublime.View) -> None:
         state.drop(view)
 
-    def on_activated(self, view):
+    def on_activated(self, view: sublime.View) -> None:
         """Re-render when the tab comes back and the file or index changed meanwhile (agent edits)"""
         if state.is_review_view(view):
             refresh_if_changed(view, state.get(view) or restore_view(view))
 
-    def on_post_save(self, view):
+    def on_post_save(self, view: sublime.View) -> None:
         """Review views showing the saved file re-render; the fingerprint decides which ones"""
         for view_id, st in state.tracked():
             review = sublime.View(view_id)

vdiff/palette.py

@@ -0,0 +1,246 @@
+""" The colour-scheme scopes vDiff paints changed lines with, provisioned into a scheme override
+
+view.add_regions repaints text with the region scope's foreground, so one scope cannot give both a
+red/green background and the file's syntax colours. This module generates a scope per (background
+kind, colour) pair carrying both, and render paints each run of same-coloured tokens with it.
+
+Sublime picks up a new override only on a restart, so the palette is probed and written in one pass
+rather than a colour at a time.
+"""
+import json
+import logging
+import os
+from typing import Any, Dict, List, Optional, Set, Tuple
+
+import sublime
+
+LOG = logging.getLogger("vdiff")
+
+# the full-line tint under the token layer, the scheme's own: the token layer repaints the text on
+# top so the tint's foreground never shows, and a scope the scheme defines needs no restart.
+SCOPE_DEL = "diff.deleted"
+SCOPE_INS = "diff.inserted"
+SCOPE_DEL_CHAR = "diff.deleted.char"
+SCOPE_INS_CHAR = "diff.inserted.char"
+
+# background kinds, and the tint each one draws over
+KINDS: Tuple[str, ...] = ("del", "ins", "del.char", "ins.char")
+KIND_TINT: Dict[str, str] = {"del": SCOPE_DEL, "ins": SCOPE_INS, "del.char": SCOPE_DEL_CHAR, "ins.char": SCOPE_INS_CHAR}
+
+# tints to provision when the active scheme defines none of its own (some third-party schemes)
+FALLBACK_TINTS: Dict[str, str] = {
+    SCOPE_DEL: "hsla(357, 45%, 60%, 0.15)",
+    SCOPE_DEL_CHAR: "hsla(357, 60%, 60%, 0.30)",
+    SCOPE_INS: "hsla(114, 31%, 68%, 0.15)",
+    SCOPE_INS_CHAR: "hsla(114, 45%, 68%, 0.30)",
+}
+
+# scope roots to probe for the scheme's palette: schemes colour by these standard names, so one pass
+# yields the working set. No API returns a scheme's palette — style_for_scope takes one scope at a
+# time, and reading the file would mean re-implementing sublime's override and .tmTheme merging.
+PALETTE_PROBES: Tuple[str, ...] = (
+    "source",
+    "comment",
+    "string",
+    "constant.numeric",
+    "constant.language",
+    "constant.character.escape",
+    "variable",
+    "variable.parameter",
+    "variable.function",
+    "keyword",
+    "keyword.operator",
+    "storage.type",
+    "storage.modifier",
+    "entity.name.function",
+    "entity.name.class",
+    "entity.name.tag",
+    "entity.other.attribute-name",
+    "entity.other.inherited-class",
+    "support.function",
+    "support.class",
+    "support.type",
+    "support.constant",
+    "punctuation.definition",
+    "punctuation.separator",
+    "meta.function-call",
+    "invalid",
+)
+
+# {override file name: {colour: index}} for every scheme provisioned this session
+_palettes: Dict[str, Dict[str, int]] = {}
+# the override name the last ensure() resolved, so scope_for knows which palette to read
+_active: Optional[str] = None
+# schemes the reader has already been told need a restart
+_notified: Set[Optional[str]] = set()
+
+
+def reset() -> None:
+    """Drop the caches, so the next ensure() re-reads and re-probes. Only the tests need this"""
+    global _active
+    _palettes.clear()
+    _notified.clear()
+    _active = None
+
+
+def claim_restart_notice(view: sublime.View) -> bool:
+    """Whether the reader still has to be told to restart, asked once per scheme
+
+    True only when a restart helps — provisioned but not yet loaded; it cannot fix one we never wrote.
+    """
+    if not (_active and _palettes.get(_active)) or tokens_resolved(view) or _active in _notified:
+        return False
+    _notified.add(_active)
+    return True
+
+
+def scope_background(view: sublime.View, scope: str) -> Optional[str]:
+    """The scheme's background for a scope, or None; style_for_scope can fail on a closing view"""
+    return _style(view, scope).get("background")
+
+
+def _style(view: sublime.View, scope: str) -> Dict[str, Any]:
+    try:
+        return view.style_for_scope(scope)
+    except Exception:
+        LOG.debug("style_for_scope failed for %s", scope, exc_info=True)
+        return {}
+
+
+def foreground(view: sublime.View, scope: str) -> Optional[str]:
+    """The scheme's foreground for a scope, normalised by sublime to #rrggbb"""
+    return _style(view, scope).get("foreground")
+
+
+def tokens_resolved(view: sublime.View) -> bool:
+    """Whether the generated (tint + colour) scopes are live
+
+    The token layer must never paint with a scope sublime does not know: it would draw that text in
+    sublime's unknown-scope green. A new override loads only on a restart, so the writing session sees false.
+    """
+    colours = (_active and _palettes.get(_active)) or {}
+    if not colours:
+        return False
+    # they are all written by the same pass into the same file, so any one of them answers for all
+    return bool(scope_background(view, _scope_name(KINDS[0], next(iter(colours.values())))))
+
+
+def scope_for(kind: str, colour: str) -> Optional[str]:
+    """The generated scope carrying `kind`'s background and `colour`, or None if never provisioned"""
+    index = _palettes.get(_active or "", {}).get(colour)
+    return None if index is None else _scope_name(kind, index)
+
+
+def token_key(scope: str) -> str:
+    """The add_regions key for a generated scope; one naming rule, spelled here only"""
+    return scope.replace("vdiff.", "vdiff.tok.", 1)
+
+
+def token_keys() -> List[str]:
+    """Every region key the token layer can use, so a re-render can erase them all"""
+    colours = _palettes.get(_active or "", {})
+    return [token_key(_scope_name(kind, i)) for kind in KINDS for i in sorted(colours.values())]
+
+
+def _scope_name(kind: str, index: int) -> str:
+    return f"vdiff.{kind}.c{index}"
+
+
+def ensure(view: sublime.View) -> None:
+    """Provision the scopes for the active scheme, once per scheme per session
+
+    Whether they have taken effect is tokens_resolved()'s question: a new override loads only on a restart.
+    """
+    global _active
+    name = override_name(view)
+    _active = name
+    if not name or name in _palettes:
+        return
+    path = os.path.join(sublime.packages_path(), "User", name)
+    try:
+        scheme: Dict[str, Any] = {}
+        if os.path.exists(path):
+            with open(path, "r", encoding="utf-8") as f:
+                # a hand-edited scheme may hold comments decode_value rejects: the raise leaves the
+                # file untouched, and render still shows the changed lines
+                scheme = sublime.decode_value(f.read()) or {}
+        rules = scheme.setdefault("rules", [])
+        tints = _tints(view)
+        colours = {colour: i for i, colour in enumerate(_probe_palette(view))}
+        _palettes[name] = colours
+        if not _merge_rules(rules, tints, colours, view):
+            return
+        os.makedirs(os.path.dirname(path), exist_ok=True)
+        with open(path, "w", encoding="utf-8") as f:
+            json.dump(scheme, f, indent=4)
+        LOG.info("provisioned %d colours into colour scheme override %s", len(colours), path)
+    except Exception:
+        LOG.warning("could not write colour scheme override %s", path, exc_info=True)
+        _palettes.setdefault(name, {})
+
+
+def _probe_palette(view: sublime.View) -> List[str]:
+    """The distinct foregrounds the active scheme uses, in probe order so indices stay meaningful"""
+    seen: List[str] = []
+    for scope in PALETTE_PROBES:
+        colour = foreground(view, scope)
+        if colour and colour not in seen:
+            seen.append(colour)
+    return seen
+
+
+def _tints(view: sublime.View) -> Dict[str, str]:
+    """{tint scope: background} for the scheme's diff colours, falling back to ours per colour pair
+
+    All or nothing per pair: taking only the half a scheme defines would put our hue next to its own.
+    """
+    tints: Dict[str, str] = {}
+    for line_scope, char_scope in ((SCOPE_DEL, SCOPE_DEL_CHAR), (SCOPE_INS, SCOPE_INS_CHAR)):
+        line = scope_background(view, line_scope)
+        char = scope_background(view, char_scope)
+        tints[line_scope] = line if line and char else FALLBACK_TINTS[line_scope]
+        tints[char_scope] = char if line and char else FALLBACK_TINTS[char_scope]
+    return tints
+
+
+def _merge_rules(rules: List[Dict[str, str]], tints: Dict[str, str], colours: Dict[str, int],
+                 view: sublime.View) -> bool:
+    """Bring the scheme's rules up to date, in place; True when anything changed
+
+    add_regions draws text in the region scope's own foreground, so each (kind, colour) pair needs a
+    rule carrying both; a background alone would flatten the line. Plain tints are written only when
+    the scheme has none, and never overwritten, so a hand-tuned one survives.
+    """
+    present = {rule.get("scope"): rule for rule in rules}
+    changed = False
+    for scope, background in tints.items():
+        if scope not in present and not scope_background(view, scope):
+            rules.append({"scope": scope, "background": background})
+            changed = True
+    for colour, index in colours.items():
+        for kind in KINDS:
+            wanted = {"scope": _scope_name(kind, index), "background": tints[KIND_TINT[kind]],
+                      "foreground": colour}
+            rule = present.get(wanted["scope"])
+            if rule is None:
+                rules.append(wanted)
+                changed = True
+            elif rule != wanted:
+                # the palette shifted under a rule an earlier session wrote; ours to keep correct
+                rule.clear()
+                rule.update(wanted)
+                changed = True
+    return changed
+
+
+def override_name(view: sublime.View) -> Optional[str]:
+    """File name in Packages/User that overrides the active scheme (same base name, .sublime-color-scheme)"""
+    try:
+        # already resolved through "auto" and dark/light settings by sublime
+        name = sublime.ui_info()["color_scheme"]["resolved_value"]
+    except Exception:
+        name = view.settings().get("color_scheme") or ""
+    if not name or name == "auto":
+        return None
+    root, _ = os.path.splitext(os.path.basename(name))
+    return root + ".sublime-color-scheme"

vdiff/parse.py

@@ -1,12 +1,32 @@
 """ Unified diff -> lines with old/new numbers, change blocks, word-level ranges; no sublime imports """
 import difflib
 import re
-from collections import Counter, namedtuple
+from collections import Counter
 from itertools import groupby
+from typing import Callable, Iterator, List, NamedTuple, Optional, Sequence, Tuple, TypeVar
 
-# kind is " " (context), "-" (deleted) or "+" (inserted); the missing number is None
+
-Line = namedtuple("Line", "kind old_no new_no text")
+class Line(NamedTuple):
-Diff = namedtuple("Diff", "lines binary")
+    """kind is " " (context), "-" (deleted) or "+" (inserted); the missing number is None"""
+
+    kind: str
+    old_no: Optional[int]
+    new_no: Optional[int]
+    text: str
+
+
+class Diff(NamedTuple):
+    lines: List[Line]
+    binary: bool
+
+
+# the value `runs` groups by, so a caller gets its own key type back rather than `object`
+Key = TypeVar("Key")
+
+# an (start, end) index range of consecutive changed lines
+Block = Tuple[int, int]
+# a (start, end) character range inside one line's text
+CharRange = Tuple[int, int]
 
 # word-level marks only when the pair is mostly the same line, and never on huge lines (quadratic)
 CHAR_DIFF_MIN_RATIO = 0.5
@@ -15,9 +35,9 @@ CHAR_DIFF_MAX_CHARS = 2000
 _HUNK = re.compile(r"@@ -(\d+)(?:,\d+)? \+(\d+)")
 
 
-def parse_unified(text):
+def parse_unified(text: str) -> Diff:
     """Parse one file's unified diff (any number of hunks) into a Diff"""
-    lines = []
+    lines: List[Line] = []
     binary = False
     old_no = new_no = 0
     in_hunk = False
@@ -52,25 +72,25 @@ def parse_unified(text):
     return Diff(lines, binary)
 
 
-def runs(items, key):
+def runs(items: Sequence[Line], key: Callable[[Line], Key]) -> Iterator[Tuple[Key, int, int]]:
     """(key value, start, end) for each maximal run of consecutive items with the same key"""
     for value, group in groupby(enumerate(items), key=lambda pair: key(pair[1])):
         indexes = [i for i, _ in group]
         yield value, indexes[0], indexes[-1] + 1
 
 
-def change_blocks(lines):
+def change_blocks(lines: Sequence[Line]) -> List[Block]:
     """[(start, end)) index ranges of consecutive changed lines"""
     return [(start, end) for changed, start, end in runs(lines, lambda line: line.kind != " ") if changed]
 
 
-def counts(lines):
+def counts(lines: Sequence[Line]) -> Tuple[int, int]:
     """(insertions, deletions)"""
     tally = Counter(line.kind for line in lines)
     return tally["+"], tally["-"]
 
 
-def paired_lines(lines, block):
+def paired_lines(lines: Sequence[Line], block: Block) -> List[Tuple[int, int]]:
     """(deleted_index, inserted_index) pairs of a block with equal - and + counts"""
     start, end = block
     deleted = [i for i in range(start, end) if lines[i].kind == "-"]
@@ -80,15 +100,15 @@ def paired_lines(lines, block):
     return list(zip(deleted, inserted))
 
 
-def char_ranges(old, new):
+def char_ranges(old: str, new: str) -> Tuple[List[CharRange], List[CharRange]]:
     """Character ranges that differ: ([(a, b) in old], [(a, b) in new]); empty when too different or too long"""
     if len(old) + len(new) > CHAR_DIFF_MAX_CHARS:
         return [], []
     matcher = difflib.SequenceMatcher(None, old, new, autojunk=False)
     if matcher.quick_ratio() < CHAR_DIFF_MIN_RATIO or matcher.ratio() < CHAR_DIFF_MIN_RATIO:
         return [], []
-    old_ranges = []
+    old_ranges: List[CharRange] = []
-    new_ranges = []
+    new_ranges: List[CharRange] = []
     for tag, i1, i2, j1, j2 in matcher.get_opcodes():
         if tag in ("replace", "delete") and i2 > i1:
             old_ranges.append((i1, i2))
@@ -97,7 +117,7 @@ def char_ranges(old, new):
     return old_ranges, new_ranges
 
 
-def line_for_open(lines, index):
+def line_for_open(lines: Sequence[Line], index: int) -> int:
     """New-file line number to open for a row: a deleted row maps to the next surviving line"""
     if not lines:
         return 1

vdiff/render.py

@@ -1,17 +1,18 @@
 """ Draw a parsed diff into a review view: the file text, coloured line regions, gutter marks, header phantom """
+import bisect
 import html
-import json
 import logging
 import os
-from collections import namedtuple
+from typing import Dict, List, NamedTuple, Optional, Sequence, Tuple
 
 import sublime
 import sublime_plugin
 
-from . import parse
+from . import palette, parse
-from .git import STATUS_NAMES
+from .git import FileChange, STATUS_NAMES
-from .state import VIEW_FLAG
+from .parse import Block, Line
-from .utils import file_count, settings
+from .state import VIEW_FLAG, ViewState
+from .utils import file_count, settings, status
 
 LOG = logging.getLogger("vdiff")
 
@@ -21,45 +22,43 @@ KEY_DEL_GUTTER = "vdiff.del.gutter"
 KEY_INS_GUTTER = "vdiff.ins.gutter"
 KEY_DEL_CHAR = "vdiff.del.char"
 KEY_INS_CHAR = "vdiff.ins.char"
-REGION_KEYS = (KEY_DEL, KEY_INS, KEY_DEL_GUTTER, KEY_INS_GUTTER, KEY_DEL_CHAR, KEY_INS_CHAR)
+REGION_KEYS: Tuple[str, ...] = (KEY_DEL, KEY_INS, KEY_DEL_GUTTER, KEY_INS_GUTTER, KEY_DEL_CHAR, KEY_INS_CHAR)
 
 PHANTOM_KEY = "vdiff.header"
 STATUS_KEY = "vdiff"
 
-# visual bell: a whole-buffer tint, erased on a timer. Deliberately not in REGION_KEYS, so the
+# visual bell: a whole-buffer tint on a timer. Not in REGION_KEYS, so a wrap's re-render cannot wipe it early.
-# re-render a wrap triggers does not wipe it before it has been seen.
 BELL_KEY = "vdiff.bell"
 BELL_MS = 90
 
-# a block phantom anchored at point 0 is drawn below row 0, so row 0 stays empty and the file starts at row 1.
+# above this much changed text the colours cost more than they are worth: such a diff is scrolled, not read
-# Only index_point / caret_index know about it.
+TOKEN_COLOUR_MAX_CHARS = 200000
+
+# a block phantom at point 0 draws below row 0, so the file starts at row 1; only index_point / caret_index know
 _HEADER_ROWS = 1
 
-# scopes with a background in every bundled colour scheme (Mariana, Monokai, Breakers, Celeste, Sixteen)
-SCOPE_DEL = "diff.deleted"
-SCOPE_INS = "diff.inserted"
-SCOPE_DEL_CHAR = "diff.deleted.char"
-SCOPE_INS_CHAR = "diff.inserted.char"
 # gutter dots use the scope's foreground
 SCOPE_DEL_MARK = "markup.deleted"
 SCOPE_INS_MARK = "markup.inserted"
 # ST4 defines region.<colour>ish in every bundled scheme for exactly this kind of transient marking
 SCOPE_BELL = "region.yellowish"
 
-# rules written into a colour-scheme override when the active scheme lacks the scopes above
+# sublime only loads an override it has not seen before on a restart
-FALLBACK_RULES = [
+NEEDS_RESTART = "restart Sublime Text to finish enabling syntax highlighting on changed lines"
-    {"scope": SCOPE_DEL, "background": "hsla(357, 45%, 60%, 0.15)", "foreground_adjust": "l(+ 5%)"},
-    {"scope": SCOPE_DEL_CHAR, "background": "hsla(357, 60%, 60%, 0.30)", "foreground_adjust": "l(+ 10%)"},
-    {"scope": SCOPE_INS, "background": "hsla(114, 31%, 68%, 0.15)", "foreground_adjust": "l(+ 5%)"},
-    {"scope": SCOPE_INS_CHAR, "background": "hsla(114, 45%, 68%, 0.30)", "foreground_adjust": "l(+ 10%)"},
-]
 
-# one source for the status-bar hints and the ? popup.
+# actions: the ACTIONS names the row covers, a single one making it a link. short: status-bar
-# actions: the ACTIONS names the row covers; a single one makes the row a link. short: status-bar
+# wording, "" keeps the row out. The group flag is False for groups needing a working-tree file.
-# wording, "" keeps the row out of it. The group flag is False for groups needing a working-tree file.
+class Key(NamedTuple):
-Key = namedtuple("Key", "keys label short actions")
+    """One row of the status-bar hints and the ? popup"""
 
-KEY_GROUPS = [
+    keys: str
+    label: str
+    short: str
+    actions: Tuple[str, ...]
+
+
+# (group title, applies in a commit, rows)
+KEY_GROUPS: List[Tuple[str, bool, List[Key]]] = [
     (
         "Navigate",
         True,
@@ -100,7 +99,7 @@ KEY_GROUPS = [
     ),
 ]
 
-KEYS = [key for _, _, group in KEY_GROUPS for key in group]
+KEYS: List[Key] = [key for _, _, group in KEY_GROUPS for key in group]
 
 KEY_HINTS = "   ".join(f"{k.keys} {k.short}" for k in KEYS if k.short)
 
@@ -124,10 +123,9 @@ a { text-decoration: none; padding: 0.15rem 0.5rem; margin-left: 0.3rem; border-
 .body { color: color(var(--foreground) alpha(0.6)); }
 """
 
-# minihtml stops applying a stylesheet at the first selector it cannot parse, and its documentation
+# minihtml drops the rest of a stylesheet at a selector it cannot parse, and documents properties
-# covers properties only, not selectors: every rule here sticks to one bare element or one class,
+# only, not selectors: every rule sticks to one bare element or class, the forms HEADER_CSS proves.
-# the forms HEADER_CSS proves work. The first group's margin stands in for body's top padding, and
+# The first group's margin stands in for body's top padding; .kdim takes its colour from .dim.
-# .kdim takes its colour from the .dim row around it.
 HELP_CSS = """
 body { margin: 0; padding: 0 0.8rem 0.6rem 0.8rem; }
 .group { margin-top: 0.6rem; color: var(--bluish); font-weight: bold; }
@@ -143,11 +141,11 @@ a { text-decoration: none; color: color(var(--foreground) alpha(0.85)); }
 class VdiffReplaceCommand(sublime_plugin.TextCommand):
     """Replace the whole buffer; the only writer of a review view"""
 
-    def run(self, edit, text):
+    def run(self, edit: sublime.Edit, text: str) -> None:
         self.view.replace(edit, sublime.Region(0, self.view.size()), text)
 
 
-def init_view(view):
+def init_view(view: sublime.View) -> None:
     """Settings a review view needs, applied once when it is created or restored"""
     s = view.settings()
     s.set(VIEW_FLAG, True)
@@ -162,8 +160,8 @@ def init_view(view):
     s.set("show_definitions", False)
     s.set("mini_diff", False)
     s.set("spell_check", False)
-    # a read-only viewer, so vim's insert mode is meaningless: open in command mode with the block
+    # a read-only viewer, so vim's insert mode is meaningless: command mode, block caret. vdiff's
-    # caret. vdiff's own keys carry no command_mode context, so they fire in either mode regardless.
+    # own keys carry no command_mode context, so they fire in either mode regardless.
     s.set("command_mode", True)
     s.set("inverse_caret_state", True)
     view.set_scratch(True)
@@ -171,53 +169,50 @@ def init_view(view):
     if not view.name():
         view.set_name("vDiff")
     view.set_status(STATUS_KEY, KEY_HINTS)
-    ensure_scheme_scopes(view)
 
 
-def index_point(view, index, col=0):
+def index_point(view: sublime.View, index: int, col: int = 0) -> int:
     """Text point of column `col` on the row showing st.lines[index]"""
     return view.text_point(index + _HEADER_ROWS, col)
 
 
-def caret_index(view):
+def caret_index(view: sublime.View) -> int:
     """Index into st.lines of the caret's row (the header row maps to -1)"""
     if not len(view.sel()):
         return 0
     return view.rowcol(view.sel()[0].begin())[0] - _HEADER_ROWS
 
 
-def fingerprint(st):
+def fingerprint(st: ViewState) -> Optional[Tuple[Optional[float], Optional[float]]]:
     """Cheap "did anything change" key for working-tree mode: mtimes of the file and of the git index"""
     if st.in_commit or st.change is None:
         return None
     return (_mtime(os.path.join(st.repo, st.change.path)), _mtime(os.path.join(st.repo, ".git", "index")))
 
 
-def _mtime(path):
+def _mtime(path: str) -> Optional[float]:
     try:
         return os.stat(path).st_mtime
     except OSError:
         return None
 
 
-def flash(view):
+def flash(view: sublime.View) -> None:
     """Visual bell: tint the buffer for a moment, for feedback that has nothing to say in words"""
     view.add_regions(BELL_KEY, [sublime.Region(0, view.size())], _bell_scope(view), flags=sublime.DRAW_NO_OUTLINE)
     # unconditional erase: overlapping flashes may cut one short, but none can leave the tint stuck
     sublime.set_timeout(lambda: view.is_valid() and view.erase_regions(BELL_KEY), BELL_MS)
 
 
-def _bell_scope(view):
+def _bell_scope(view: sublime.View) -> str:
-    """region.yellowish, or a scope the plugin guarantees a background for when a scheme lacks it"""
+    """region.yellowish, or a scope with a background we know of when a scheme lacks it"""
-    try:
+    if palette.scope_background(view, SCOPE_BELL):
-        if view.style_for_scope(SCOPE_BELL).get("background"):
+        return SCOPE_BELL
-            return SCOPE_BELL
+    # an invisible bell is a silent failure, so borrow the insert tint
-    except Exception:
+    return palette.SCOPE_INS
-        LOG.debug("style_for_scope failed for %s", SCOPE_BELL, exc_info=True)
-    return SCOPE_INS
 
 
-def render_message(view, st, message):
+def render_message(view: sublime.View, st: ViewState, message: str) -> None:
     """Show a one-line notice instead of a file (nothing to review, binary, ...)"""
     st.change = None
     st.lines = []
@@ -228,8 +223,11 @@ def render_message(view, st, message):
     _finish(view, st, 0, 0, "vDiff")
 
 
-def render(view, st):
+def render(view: sublime.View, st: ViewState) -> None:
     """Draw st.lines for st.change into the view"""
+    change = st.change
+    # every caller with nothing to show goes to render_message instead, so there is a file here
+    assert change is not None
     lines = st.lines
     if st.binary:
         text = "(binary file)"
@@ -239,32 +237,117 @@ def render(view, st):
         text = "\n".join(line.text for line in lines)
 
     _replace(view, text)
-    path = os.path.join(st.repo, st.change.path)
+    path = os.path.join(st.repo, change.path)
     _apply_syntax(view, path if lines and not st.binary else None)
 
     if lines and not st.binary:
-        starts = _row_starts(lines)
+        # here rather than init_view: during a session restore the scheme colours still read as absent
-        deleted, inserted = _line_regions(lines, starts)
+        palette.ensure(view)
-        view.add_regions(KEY_DEL, deleted, SCOPE_DEL, flags=sublime.DRAW_NO_OUTLINE)
+        _paint_regions(view, st)
-        view.add_regions(KEY_INS, inserted, SCOPE_INS, flags=sublime.DRAW_NO_OUTLINE)
+        if palette.claim_restart_notice(view):
-        mark_flags = sublime.DRAW_NO_FILL | sublime.DRAW_NO_OUTLINE
+            status(NEEDS_RESTART)
-        del_marks = [sublime.Region(starts[i]) for i, line in enumerate(lines) if line.kind == "-"]
-        ins_marks = [sublime.Region(starts[i]) for i, line in enumerate(lines) if line.kind == "+"]
-        view.add_regions(KEY_DEL_GUTTER, del_marks, SCOPE_DEL_MARK, icon="dot", flags=mark_flags)
-        view.add_regions(KEY_INS_GUTTER, ins_marks, SCOPE_INS_MARK, icon="dot", flags=mark_flags)
-        if settings().get("word_diff", True):
-            del_chars, ins_chars = _char_regions(lines, st.blocks, starts)
-            view.add_regions(KEY_DEL_CHAR, del_chars, SCOPE_DEL_CHAR, flags=sublime.DRAW_NO_OUTLINE)
-            view.add_regions(KEY_INS_CHAR, ins_chars, SCOPE_INS_CHAR, flags=sublime.DRAW_NO_OUTLINE)
 
     ins, dele = parse.counts(lines)
-    _finish(view, st, ins, dele, f"⟐ {os.path.basename(st.change.path)}")
+    _finish(view, st, ins, dele, f"⟐ {os.path.basename(change.path)}")
     view.sel().clear()
     view.sel().add(sublime.Region(index_point(view, 0)))
     view.set_viewport_position((0, 0), False)
 
 
-def _finish(view, st, ins, dele, name):
+def _paint_regions(view: sublime.View, st: ViewState) -> None:
+    """The line tint, the gutter dots, the word-diff marks, and the syntax colours on top of them"""
+    lines = st.lines
+    starts = _row_starts(lines)
+    deleted, inserted = _line_regions(lines, starts)
+    view.add_regions(KEY_DEL, deleted, palette.SCOPE_DEL, flags=sublime.DRAW_NO_OUTLINE)
+    view.add_regions(KEY_INS, inserted, palette.SCOPE_INS, flags=sublime.DRAW_NO_OUTLINE)
+    mark_flags = sublime.DRAW_NO_FILL | sublime.DRAW_NO_OUTLINE
+    del_marks = [sublime.Region(starts[i]) for i, line in enumerate(lines) if line.kind == "-"]
+    ins_marks = [sublime.Region(starts[i]) for i, line in enumerate(lines) if line.kind == "+"]
+    view.add_regions(KEY_DEL_GUTTER, del_marks, SCOPE_DEL_MARK, icon="dot", flags=mark_flags)
+    view.add_regions(KEY_INS_GUTTER, ins_marks, SCOPE_INS_MARK, icon="dot", flags=mark_flags)
+    del_chars: List[sublime.Region] = []
+    ins_chars: List[sublime.Region] = []
+    if settings().get("word_diff", True):
+        del_chars, ins_chars = _char_regions(lines, st.blocks, starts)
+        view.add_regions(KEY_DEL_CHAR, del_chars, palette.SCOPE_DEL_CHAR, flags=sublime.DRAW_NO_OUTLINE)
+        view.add_regions(KEY_INS_CHAR, ins_chars, palette.SCOPE_INS_CHAR, flags=sublime.DRAW_NO_OUTLINE)
+    _paint_tokens(view, lines, starts, del_chars + ins_chars)
+
+
+def _paint_tokens(view: sublime.View, lines: Sequence[Line], starts: Sequence[int],
+                  char_regions: Sequence[sublime.Region]) -> None:
+    """Repaint each run of same-coloured tokens with a scope carrying the tint *and* that colour
+
+    add_regions draws text in the region scope's own foreground, so the tints above have just
+    flattened every changed line; only handing each run its own colour gives the highlighting back.
+    """
+    if not palette.tokens_resolved(view):
+        return
+    changed = [i for i, line in enumerate(lines) if line.kind != " "]
+    if sum(len(lines[i].text) for i in changed) > TOKEN_COLOUR_MAX_CHARS:
+        # a huge diff would spend longer being tokenised than read; the flat tint still shows it
+        return
+
+    stronger = sorted((r.a, r.b) for r in char_regions)
+    starts_of = [a for a, _ in stronger]
+    groups: Dict[str, List[sublime.Region]] = {}
+    colours: Dict[str, Optional[str]] = {}  # scope name -> colour, resolved once per render
+    for i in changed:
+        kind = "del" if lines[i].kind == "-" else "ins"
+        end = starts[i] + len(lines[i].text)
+        # only this line's word-diff ranges, so a diff with thousands of them stays linear
+        on_line = stronger[bisect.bisect_left(starts_of, starts[i]):bisect.bisect_left(starts_of, end)]
+        for region, colour in _colour_runs(view, starts[i], lines[i].text, colours):
+            # a word-diff range cuts across token boundaries, so the run splits on it
+            for part, inside in _split(region, on_line):
+                # a colour outside the scheme's probed palette keeps the plain tint under it
+                scope = palette.scope_for(kind + ".char" if inside else kind, colour)
+                if scope:
+                    groups.setdefault(scope, []).append(part)
+    for scope, regions in groups.items():
+        view.add_regions(palette.token_key(scope), regions, scope, flags=sublime.DRAW_NO_OUTLINE)
+
+
+def _split(region: sublime.Region, intervals: Sequence[Tuple[int, int]]) -> List[Tuple[sublime.Region, bool]]:
+    """(part, inside) covering `region`, cut wherever one of the sorted `intervals` starts or ends"""
+    if not intervals:
+        return [(region, False)]
+    parts: List[Tuple[sublime.Region, bool]] = []
+    pos = region.a
+    for a, b in intervals:
+        a, b = max(a, region.a), min(b, region.b)
+        if b <= pos:
+            continue
+        if a >= region.b:
+            break
+        if a > pos:
+            parts.append((sublime.Region(pos, a), False))
+        parts.append((sublime.Region(a, b), True))
+        pos = b
+    if pos < region.b or not parts:
+        parts.append((sublime.Region(pos, region.b), False))
+    return parts
+
+
+def _colour_runs(view: sublime.View, start: int, text: str,
+                 colours: Dict[str, Optional[str]]) -> List[Tuple[sublime.Region, str]]:
+    """(region, colour) per run of same-coloured tokens on one line, adjacent equal colours merged"""
+    runs: List[Tuple[sublime.Region, str]] = []
+    for region, scope in view.extract_tokens_with_scopes(sublime.Region(start, start + len(text))):
+        if scope not in colours:
+            colours[scope] = palette.foreground(view, scope)
+        colour = colours[scope]
+        if not colour:
+            continue
+        if runs and runs[-1][1] == colour and runs[-1][0].b == region.a:
+            runs[-1] = (sublime.Region(runs[-1][0].a, region.b), colour)
+        else:
+            runs.append((region, colour))
+    return runs
+
+
+def _finish(view: sublime.View, st: ViewState, ins: int, dele: int, name: str) -> None:
     """Header, tab name, status bar and bookkeeping shared by render and render_message"""
     _header(view, st, ins, dele)
     view.set_name(name)
@@ -273,17 +356,18 @@ def _finish(view, st, ins, dele, name):
     st.fingerprint = fingerprint(st)
 
 
-def _replace(view, text):
+def _replace(view: sublime.View, text: str) -> None:
     view.set_read_only(False)
     try:
         view.run_command("vdiff_replace", {"text": "\n" * _HEADER_ROWS + text})
     finally:
         view.set_read_only(True)
-    for key in REGION_KEYS:
+    # the token layer's keys vary with the palette, so they are listed rather than fixed
+    for key in list(REGION_KEYS) + palette.token_keys():
         view.erase_regions(key)
 
 
-def _apply_syntax(view, path):
+def _apply_syntax(view: sublime.View, path: Optional[str]) -> None:
     """The real file's syntax, so the diff is highlighted like the file itself"""
     syntax = None
     if path:
@@ -294,9 +378,9 @@ def _apply_syntax(view, path):
     view.assign_syntax(syntax.path if syntax else "scope:text.plain")
 
 
-def _row_starts(lines):
+def _row_starts(lines: Sequence[Line]) -> List[int]:
     """Text point where each line starts; computed from the text we wrote, no view round-trips"""
-    starts = []
+    starts: List[int] = []
     point = _HEADER_ROWS
     for line in lines:
         starts.append(point)
@@ -305,9 +389,10 @@ def _row_starts(lines):
     return starts
 
 
-def _line_regions(lines, starts):
+def _line_regions(lines: Sequence[Line],
+                  starts: Sequence[int]) -> Tuple[List[sublime.Region], List[sublime.Region]]:
     """Full-line regions of deleted and inserted rows, consecutive rows merged"""
-    regions = {"-": [], "+": []}
+    regions: Dict[str, List[sublime.Region]] = {"-": [], "+": []}
     for kind, start, end in parse.runs(lines, lambda line: line.kind):
         if kind in regions:
             # starts has a sentinel at len(lines): the last line stops at the buffer end
@@ -315,10 +400,11 @@ def _line_regions(lines, starts):
     return regions["-"], regions["+"]
 
 
-def _char_regions(lines, blocks, starts):
+def _char_regions(lines: Sequence[Line], blocks: Sequence[Block],
+                  starts: Sequence[int]) -> Tuple[List[sublime.Region], List[sublime.Region]]:
     """Changed characters inside paired deleted/inserted lines"""
-    deleted = []
+    deleted: List[sublime.Region] = []
-    inserted = []
+    inserted: List[sublime.Region] = []
     for block in blocks:
         for del_row, ins_row in parse.paired_lines(lines, block):
             old_ranges, new_ranges = parse.char_ranges(lines[del_row].text, lines[ins_row].text)
@@ -327,12 +413,12 @@ def _char_regions(lines, blocks, starts):
     return deleted, inserted
 
 
-def _totals(files):
+def _totals(files: Sequence[FileChange]) -> Tuple[int, int]:
     """Summed numstat counts; binary files carry None counts and add nothing"""
     return sum(c.insertions or 0 for c in files), sum(c.deletions or 0 for c in files)
 
 
-def _summary_html(st):
+def _summary_html(st: ViewState) -> str:
     """Line above the header: the whole commit on one line, or how much of the tree is staged"""
     if not st.files and not st.commit:
         return ""
@@ -349,10 +435,10 @@ def _summary_html(st):
     return f'<div class="summary">{text}</div>'
 
 
-def _commit_parts(st):
+def _commit_parts(st: ViewState) -> List[str]:
     """hash, author, date, totals and message — everything about the reviewed commit, in that order"""
     info = st.commit
-    parts = []
+    parts: List[str] = []
     if info:
         parts.append(f'<span class="hash">{html.escape(info.short)}</span>')
         parts.append(html.escape(info.author))
@@ -369,7 +455,7 @@ def _commit_parts(st):
     return parts
 
 
-def header_html(st, ins, dele):
+def header_html(st: ViewState, ins: int, dele: int) -> str:
     """The minihtml header: the summary line, then the shown file's path, counts, state and action links"""
     change = st.change
     if change is None:
@@ -384,7 +470,7 @@ def header_html(st, ins, dele):
             if state:
                 title += f'&nbsp;&nbsp;<span class="state">{state}</span>'
 
-    actions = []
+    actions: List[str] = []
     if change is not None and not st.in_commit:
         actions.append('<a href="stage">Stage</a>')
         actions.append('<a href="unstage">Unstage</a>')
@@ -401,15 +487,15 @@ def header_html(st, ins, dele):
     )
 
 
-def _run_action(view, href):
+def _run_action(view: sublime.View, href: str) -> None:
     """Dispatch a header or popup link through the same command the keymap uses"""
     view.run_command("vdiff_action", {"action": href})
 
 
-def _header(view, st, ins, dele):
+def _header(view: sublime.View, st: ViewState, ins: int, dele: int) -> None:
     """One block phantom above the text; redrawn from scratch, so no PhantomSet state to keep"""
 
-    def navigate(href):
+    def navigate(href: str) -> None:
         _run_action(view, href)
 
     view.erase_phantoms(PHANTOM_KEY)
@@ -419,9 +505,9 @@ def _header(view, st, ins, dele):
 # --- key help popup ---------------------------------------------------------
 
 
-def help_html(st):
+def help_html(st: ViewState) -> str:
     """The minihtml key list; rows that need a working-tree file are dimmed while a commit is shown"""
-    parts = []
+    parts: List[str] = []
     for title, applies, group in KEY_GROUPS:
         dim = st.in_commit and not applies
         heading = html.escape(title)
@@ -441,13 +527,13 @@ def help_html(st):
     return f'<body id="vdiff-help"><style>{HELP_CSS}</style>{"".join(parts)}</body>'
 
 
-def show_help(view, st):
+def show_help(view: sublime.View, st: ViewState) -> None:
     """Toggle the key list popup at the caret"""
     if view.is_popup_visible():
         view.hide_popup()
         return
 
-    def navigate(href):
+    def navigate(href: str) -> None:
         view.hide_popup()
         _run_action(view, href)
 
@@ -455,47 +541,3 @@ def show_help(view, st):
     em = view.em_width() or 8
     view.show_popup(help_html(st), location=-1, max_width=int(em * 56), max_height=int(em * 44), on_navigate=navigate)
 
-
-# --- colour scheme fallback -------------------------------------------------
-
-_scheme_checked = set()
-
-
-def ensure_scheme_scopes(view):
-    """Write a scheme override with diff backgrounds when the active scheme has none (third-party schemes)"""
-    name = _scheme_override_name(view)
-    if not name or name in _scheme_checked:
-        return
-    _scheme_checked.add(name)
-    try:
-        if view.style_for_scope(SCOPE_INS).get("background"):
-            return
-    except Exception:
-        return
-    path = os.path.join(sublime.packages_path(), "User", name)
-    try:
-        scheme = {}
-        if os.path.exists(path):
-            with open(path, "r", encoding="utf-8") as f:
-                scheme = sublime.decode_value(f.read()) or {}
-        rules = scheme.setdefault("rules", [])
-        present = {rule.get("scope") for rule in rules}
-        rules.extend(rule for rule in FALLBACK_RULES if rule["scope"] not in present)
-        with open(path, "w", encoding="utf-8") as f:
-            json.dump(scheme, f, indent=4)
-        LOG.info("wrote diff scopes into colour scheme override %s", path)
-    except Exception:
-        LOG.warning("could not write colour scheme override %s", path, exc_info=True)
-
-
-def _scheme_override_name(view):
-    """File name in Packages/User that overrides the active scheme (same base name, .sublime-color-scheme)"""
-    try:
-        # already resolved through "auto" and dark/light settings by sublime
-        name = sublime.ui_info()["color_scheme"]["resolved_value"]
-    except Exception:
-        name = view.settings().get("color_scheme") or ""
-    if not name or name == "auto":
-        return None
-    root, _ = os.path.splitext(os.path.basename(name))
-    return root + ".sublime-color-scheme"

vdiff/state.py

@@ -1,17 +1,30 @@
 """ Per-view state of review views, keyed by view id; the essentials are mirrored into view settings for restore """
-from collections import namedtuple
 from dataclasses import dataclass, field
+from typing import TYPE_CHECKING, Any, Dict, List, NamedTuple, Optional, Sequence, Tuple
+
+if TYPE_CHECKING:
+    # annotation-only, so this module keeps importing neither sublime nor the rest of the package
+    import sublime
+
+    from .git import CommitInfo, FileChange
+    from .parse import Block, Line
 
 # view setting marking a review view (keymap context "setting.vdiff_view")
 VIEW_FLAG = "vdiff_view"
 # view setting holding what the view shows, so a restored tab can re-render
 VIEW_DATA = "vdiff"
 
-# what a quick panel goes back to on Esc
+
-Kept = namedtuple("Kept", "sha commit change files")
+class Kept(NamedTuple):
+    """What a quick panel goes back to on Esc"""
+
+    sha: Optional[str]
+    commit: Optional["CommitInfo"]
+    change: Optional["FileChange"]
+    files: List["FileChange"]
 
 
-def find_change(files, path):
+def find_change(files: Sequence["FileChange"], path: Optional[str]) -> int:
     """Index of the FileChange with `path`, or -1"""
     for i, change in enumerate(files):
         if change.path == path:
@@ -21,42 +34,40 @@ def find_change(files, path):
 
 @dataclass(eq=False)
 class ViewState:
-    """Everything a review view needs to re-render itself and act on its file
+    """Everything a review view needs to re-render itself and act on its file"""
-
-    `sha` is None in working-tree mode and the reviewed commit's hash otherwise.
-    """
 
     repo: str
-    sha: object = None  # None in working-tree mode, the reviewed commit's hash otherwise
+    sha: Optional[str] = None  # None in working-tree mode, the reviewed commit's hash otherwise
-    commit: object = None  # git.CommitInfo when sha is set
+    commit: Optional["CommitInfo"] = None  # set when sha is
-    change: object = None  # git.FileChange currently shown
+    change: Optional["FileChange"] = None  # file currently shown
-    requested: object = None  # file asked for, maybe still loading; navigation counts from here
+    requested: Optional["FileChange"] = None  # file asked for, maybe still loading; navigation counts from here
-    files: list = field(default_factory=list)  # git.FileChange list the user is browsing (next/prev file)
+    files: List["FileChange"] = field(default_factory=list)  # what the user is browsing (next/prev file)
-    lines: list = field(default_factory=list)  # parse.Line list currently rendered
+    lines: List["Line"] = field(default_factory=list)  # currently rendered
-    blocks: list = field(default_factory=list)  # parse.change_blocks(lines)
+    blocks: List["Block"] = field(default_factory=list)  # parse.change_blocks(lines)
     binary: bool = False
     token: int = 0  # bumped per show request; a stale async result is dropped
     rendered_token: int = -1  # token of the request that produced the current render
     highlight: int = 0  # bumped per quick-panel highlight, to debounce previews
-    fingerprint: object = None  # (file mtime, index mtime) at render time, working-tree mode
+    # (file mtime, index mtime) at render time, working-tree mode; either mtime is None when unreadable
+    fingerprint: Optional[Tuple[Optional[float], Optional[float]]] = None
 
     @property
-    def in_commit(self):
+    def in_commit(self) -> bool:
         return self.sha is not None
 
-    def index(self):
+    def index(self) -> int:
         """Position in `files` of the file being shown or loaded, or -1
 
-        `requested` leads: a diff arrives asynchronously, so counting from `change` alone would make
+        `requested` leads: a diff arrives asynchronously, so counting from `change` would make n / p
-        n / p step from whatever was on screen before the pending file landed.
+        step from what was on screen before the pending file landed.
         """
         change = self.requested or self.change
         return find_change(self.files, change.path) if change else -1
 
-    def kept(self):
+    def kept(self) -> Kept:
         return Kept(self.sha, self.commit, self.change, list(self.files))
 
-    def enter(self, sha=None, commit=None):
+    def enter(self, sha: Optional[str] = None, commit: Optional["CommitInfo"] = None) -> Kept:
         """Switch to browsing a commit (or the working tree); returns what to restore on Esc"""
         kept = self.kept()
         if sha != self.sha:
@@ -64,13 +75,13 @@ class ViewState:
         self.sha, self.commit = sha, commit
         return kept
 
-    def restore(self, kept):
+    def restore(self, kept: Kept) -> None:
         self.sha, self.commit, self.change, self.files = kept
         self.requested = kept.change
 
-    def persist(self, view):
+    def persist(self, view: "sublime.View") -> None:
         """Mirror the essentials into view settings (survives a restart)"""
-        data = {"repo": self.repo, "sha": self.sha}
+        data: Dict[str, Any] = {"repo": self.repo, "sha": self.sha}
         if self.change:
             data["path"] = self.change.path
             data["status"] = self.change.status
@@ -78,26 +89,26 @@ class ViewState:
         view.settings().set(VIEW_DATA, data)
 
 
-STATES = {}
+STATES: Dict[int, "ViewState"] = {}
 
 
-def get(view):
+def get(view: "sublime.View") -> Optional[ViewState]:
     return STATES.get(view.id())
 
 
-def tracked():
+def tracked() -> List[Tuple[int, ViewState]]:
     """Snapshot of (view id, state) for every tracked review view"""
     return list(STATES.items())
 
 
-def put(view, st):
+def put(view: "sublime.View", st: ViewState) -> ViewState:
     STATES[view.id()] = st
     return st
 
 
-def drop(view):
+def drop(view: "sublime.View") -> None:
     STATES.pop(view.id(), None)
 
 
-def is_review_view(view):
+def is_review_view(view: Optional["sublime.View"]) -> bool:
     return bool(view and view.settings().get(VIEW_FLAG))

vdiff/utils.py

@@ -1,5 +1,6 @@
 """ Small helpers shared across vdiff modules """
 import logging
+from typing import Any, Callable, Optional
 
 import sublime
 
@@ -9,10 +10,10 @@ SETTINGS_FILE = "vDiff.sublime-settings"
 
 LOG = logging.getLogger("vdiff")
 
-_settings = None
+_settings: Optional[sublime.Settings] = None
 
 
-def settings():
+def settings() -> sublime.Settings:
     """Cached settings handle; a sublime Settings object stays live"""
     global _settings
     if _settings is None:
@@ -22,25 +23,25 @@ def settings():
     return _settings
 
 
-def apply_git_binary():
+def apply_git_binary() -> None:
     """Push the configured git executable into the (sublime-free) git module"""
     git.GIT_BINARY = settings().get("git_binary") or "git"
 
 
-def file_count(count):
+def file_count(count: int) -> str:
     """'1 file' / '3 files' for a message"""
     return f'{count} {"file" if count == 1 else "files"}'
 
 
-def status(message):
+def status(message: str) -> None:
     """Status-bar message with the plugin prefix"""
     sublime.status_message(f"vDiff: {message}")
 
 
-def run_async(work, done):
+def run_async(work: Callable[[], Any], done: Callable[[Any], None]) -> None:
     """Run `work()` on sublime's worker thread, hand the result to `done` on the main thread"""
 
-    def job():
+    def job() -> None:
         try:
             result = work()
         except Exception as error: