Add [a]/[b] to toggle sides in the inline diff

Default.sublime-keymap

@@ -150,6 +150,24 @@
             { "key": "setting.git_savvy.inline_diff_view", "operator": "equal", "operand": true }
         ]
     },
+    {
+        "keys": ["a"],
+        "command": "gs_inline_diff_toggle_side",
+        "args": {"side": "a"},
+        "context": [
+            { "key": "setting.command_mode", "operator": "equal", "operand": false },
+            { "key": "setting.git_savvy.inline_diff_view", "operator": "equal", "operand": true }
+        ]
+    },
+    {
+        "keys": ["b"],
+        "command": "gs_inline_diff_toggle_side",
+        "args": {"side": "b"},
+        "context": [
+            { "key": "setting.command_mode", "operator": "equal", "operand": false },
+            { "key": "setting.git_savvy.inline_diff_view", "operator": "equal", "operand": true }
+        ]
+    },
     {
         "keys": ["tab"],
         "command": "gs_inline_diff_toggle_cached_mode",

core/commands/_help_popups.py

@@ -112,6 +112,7 @@ class gs_inline_diff_help_tooltip(GsAbstractHelpPopup):
     key_bindings = dedent("""\
     ### Actions ###
     [tab]          switch between staged/unstaged area
+    [a]/[b]        show/hide the a and b (red or green) sides of the diff
     [l]            stage line, unstage in cached mode
     [h]            stage hunk, unstage in cached mode
     [L]            reset line

core/commands/inline_diff.py

@@ -21,6 +21,7 @@
     "gs_inline_diff",
     "gs_inline_diff_open",
     "gs_inline_diff_refresh",
+    "gs_inline_diff_toggle_side",
     "gs_inline_diff_toggle_cached_mode",
     "gs_inline_diff_stage_or_reset_line",
     "gs_inline_diff_stage_or_reset_hunk",
@@ -37,7 +38,7 @@
 
 MYPY = False
 if MYPY:
-    from typing import Dict, Iterable, List, NamedTuple, Optional, Tuple
+    from typing import Dict, Iterable, List, Literal, NamedTuple, Optional, Tuple
     from ..types import LineNo, ColNo, Row
     from GitSavvy.common.util.parse_diff import Hunk as InlineDiff_Hunk
 
@@ -471,17 +472,18 @@ def draw(self, view, title, match_position, inline_diff_contents, hunks):
             and self.savvy_settings.get("inline_diff_auto_scroll", True)
         )
 
-        replace_view_content(view, inline_diff_contents)
-        self.view.set_name(title)
+        with reapply_possible_fold(view):
+            replace_view_content(view, inline_diff_contents)
+            view.set_name(title)
 
-        if match_position:
-            row, col, row_offset = match_position
-            new_row = translate_row_to_inline_diff(view, row)
-            apply_position(view, new_row, col, row_offset)
-        elif navigate_to_first_hunk:
-            view.run_command("gs_inline_diff_navigate_hunk")
+            if match_position:
+                row, col, row_offset = match_position
+                new_row = translate_row_to_inline_diff(view, row)
+                apply_position(view, new_row, col, row_offset)
+            elif navigate_to_first_hunk:
+                view.run_command("gs_inline_diff_navigate_hunk")
 
-        self.highlight_regions(hunks)
+            self.highlight_regions(hunks)
 
     def get_inline_diff_contents(self, original_contents, diff):
         # type: (str, List[InlineDiff_Hunk]) -> Tuple[str, List[HunkReference]]
@@ -608,6 +610,57 @@ def highlight_regions(self, replaced_lines):
         )
 
 
+@contextmanager
+def reapply_possible_fold(view):
+    current_fold_mode = fold_mode(view)
+    if current_fold_mode == "ab":
+        yield
+    else:
+        view.run_command("unfold_all")
+        yield
+        view.run_command("gs_inline_diff_toggle_side", {"side": current_fold_mode})
+
+
+def fold_mode(view):
+    # type: (sublime.View) -> Literal["a", "b", "ab"]
+    currently_folded = view.folded_regions()
+    if not currently_folded:
+        return "ab"
+    if currently_folded == regions(view, "b"):
+        return "a"
+    if currently_folded == regions(view, "a"):
+        return "b"
+    return "ab"
+
+
+def regions(view, side):
+    # type: (sublime.View, Literal["a", "b"]) -> List[sublime.Region]
+    selector = "git-savvy-removed-lines" if side == "a" else "git-savvy-added-lines"
+    return [sublime.Region(r.a, r.b - 1) for r in view.get_regions(selector)]
+
+
+class gs_inline_diff_toggle_side(TextCommand, GitCommand):
+    def run(self, edit, side):
+        # type: (sublime.Edit, Literal["a", "b"]) -> None
+        view = self.view
+        currently_folded = view.folded_regions()
+
+        if side == "a":
+            b_regions = regions(view, "b")
+            if currently_folded:
+                view.run_command("unfold_all")
+            if currently_folded == b_regions:
+                return
+            view.fold(b_regions)
+        else:
+            a_regions = regions(view, "a")
+            if currently_folded:
+                view.run_command("unfold_all")
+            if currently_folded == a_regions:
+                return
+            view.fold(a_regions)
+
+
 class gs_inline_diff_toggle_cached_mode(TextCommand, GitCommand):
 
     """