"[" and "]" cycle over changes (hunks)

README.md

@@ -21,7 +21,7 @@ Keys inside the review view:
 | `s` / `u` / `d` | stage / unstage / discard the file (uncommitted mode) |
 | `C` or `m` | commit the staged files, typing the message in an input panel |
 | `o` or Enter | open the real file at this line |
-| `]` / `[` | next / previous change |
+| `]` / `[` | next / previous change (wraps at the ends) |
 | `n` / `p` | next / previous file of the current list (wraps at the ends) |
 | `j` / `k` | move down / up one line (vim keys) |
 | `r` | refresh |

tests/test_commands.py

@@ -403,3 +403,51 @@ def test_first_step_without_a_shown_file_picks_an_end(loading, rings):
     assert requested_path(queue) == "f4.py"
     # neither is a wrap: there was no position to run past
     assert rings == []
+
+
+def at_change(blocks, row):
+    """A rendered view with `blocks` as its changes and the caret on `row`"""
+    view = sublime.View()
+    st = state.ViewState("/repo")
+    st.blocks = blocks
+    view.text = "\n" + "\n".join("l{}".format(i) for i in range(20))
+    view.sel().add(sublime.Region(commands.render.index_point(view, row)))
+    return view, st
+
+
+def test_next_change_wraps_past_the_last(rings):
+    view, st = at_change([(2, 4), (7, 8)], 7)
+
+    commands.ACTIONS["next_change"](view, None, st)
+    assert commands.render.caret_index(view) == 2 and len(rings) == 1
+
+
+def test_prev_change_wraps_before_the_first(rings):
+    view, st = at_change([(2, 4), (7, 8)], 2)
+
+    commands.ACTIONS["prev_change"](view, None, st)
+    assert commands.render.caret_index(view) == 7 and len(rings) == 1
+
+
+def test_stepping_inside_the_changes_does_not_ring(rings):
+    view, st = at_change([(2, 4), (7, 8), (12, 13)], 7)
+
+    commands.ACTIONS["next_change"](view, None, st)
+    commands.ACTIONS["prev_change"](view, None, st)
+    assert commands.render.caret_index(view) == 7 and rings == []
+
+
+def test_single_change_rings_and_stays_put(rings):
+    view, st = at_change([(2, 4)], 2)
+
+    commands.ACTIONS["next_change"](view, None, st)
+    commands.ACTIONS["prev_change"](view, None, st)
+    assert commands.render.caret_index(view) == 2 and len(rings) == 2
+
+
+def test_a_file_without_changes_neither_moves_nor_rings(rings):
+    view, st = at_change([], 3)
+
+    commands.ACTIONS["next_change"](view, None, st)
+    commands.ACTIONS["prev_change"](view, None, st)
+    assert commands.render.caret_index(view) == 3 and rings == []

vdiff/commands.py

@@ -380,11 +380,15 @@ def _step_file(delta):
 def _step_change(delta):
     def act(view, window, st):
         starts = [start for start, _ in st.blocks]
+        if not starts:
+            status("no changes")
+            return
         row = render.caret_index(view)
         position = bisect.bisect_right(starts, row) if delta > 0 else bisect.bisect_left(starts, row) - 1
-        if not 0 <= position < len(starts):
-            status("no more changes")
-            return
+        wrapped = not 0 <= position < len(starts)
+        position %= len(starts)  # -1 is the last change, len(starts) the first
+        if wrapped:
+            render.flash(view)
         point = render.index_point(view, starts[position])
         view.sel().clear()
         view.sel().add(sublime.Region(point))

vdiff/render.py

@@ -61,7 +61,7 @@ Key = namedtuple("Key", "keys label short actions")
 
 KEY_GROUPS = [
     ("Navigate", True, [
-        Key("] [", "next / previous change", "change", ("next_change", "prev_change")),
+        Key("] [", "next / previous change (wraps)", "change", ("next_change", "prev_change")),
         Key("n p", "next / previous file (wraps)", "file", ("next_file", "prev_file")),
         Key("o \u23ce", "open the real file at this line", "open", ("open",)),
         Key("j k", "down / up one line (vim)", "", ("line_down", "line_up")),