feat: add ]c/[c change line jump navigation

Add Vim-style ]c (next change) and [c (previous change) keybindings
to jump between add/delete lines in the PR detail diff view. Uses a
pendingBracket state for 2-key sequence handling with visual feedback
in the footer.

https://claude.ai/code/session_015NbnHYsXMH45WpAakjZoki

Author: claude

src/components/Help.tsx

@@ -49,6 +49,8 @@ export function Help({ onClose }: Props) {
         <KeyRow keyName="G" description="Jump to end" />
         <KeyRow keyName="n" description="Next file" />
         <KeyRow keyName="N" description="Previous file" />
+        <KeyRow keyName="]c" description="Next change (add/delete line)" />
+        <KeyRow keyName="[c" description="Previous change (add/delete line)" />
         <KeyRow keyName="f" description="File list" />
         <KeyRow keyName="Enter" description="Select / confirm" />
         <KeyRow keyName="q / Esc" description="Back / quit" />

src/components/PullRequestDetail.test.tsx

@@ -7986,4 +7986,159 @@ describe("PullRequestDetail", () => {
     stdin.write("g");
     expect(lastFrame()).not.toContain("React to comment:");
   });
+
+  it("]c jumps to next add/delete line", async () => {
+    const { stdin, lastFrame } = render(
+      <PullRequestDetail
+        pullRequest={pullRequest as any}
+        differences={differences as any}
+        commentThreads={[] as any}
+        diffTexts={diffTexts}
+        onBack={vi.fn()}
+        onHelp={vi.fn()}
+        onShowActivity={vi.fn()}
+        comment={{ onPost: vi.fn(), isProcessing: false, error: null, onClearError: vi.fn() }}
+        inlineComment={defaultInlineCommentProps}
+        reply={defaultReplyProps}
+        approval={defaultApprovalProps}
+        merge={defaultMergeProps}
+        close={defaultCloseProps}
+        commitView={defaultCommitProps}
+        editComment={defaultEditCommentProps}
+        deleteComment={defaultDeleteCommentProps}
+        reaction={defaultReactionProps}
+      />,
+    );
+
+    // Cursor starts at index 0 (header). Press ]c to jump to first change line.
+    stdin.write("]");
+    await vi.waitFor(() => {
+      expect(lastFrame()).toContain("]_");
+    });
+    stdin.write("c");
+    await vi.waitFor(() => {
+      const output = lastFrame()!;
+      // Should land on a delete or add line (contains - or +)
+      expect(output).toMatch(/>.*│.*[-+]/);
+    });
+  });
+
+  it("[c jumps to previous add/delete line", async () => {
+    const { stdin, lastFrame } = render(
+      <PullRequestDetail
+        pullRequest={pullRequest as any}
+        differences={differences as any}
+        commentThreads={[] as any}
+        diffTexts={diffTexts}
+        onBack={vi.fn()}
+        onHelp={vi.fn()}
+        onShowActivity={vi.fn()}
+        comment={{ onPost: vi.fn(), isProcessing: false, error: null, onClearError: vi.fn() }}
+        inlineComment={defaultInlineCommentProps}
+        reply={defaultReplyProps}
+        approval={defaultApprovalProps}
+        merge={defaultMergeProps}
+        close={defaultCloseProps}
+        commitView={defaultCommitProps}
+        editComment={defaultEditCommentProps}
+        deleteComment={defaultDeleteCommentProps}
+        reaction={defaultReactionProps}
+      />,
+    );
+
+    // Jump to end first, then [c to find previous change
+    stdin.write("G");
+    await vi.waitFor(() => {
+      expect(lastFrame()).toBeTruthy();
+    });
+    stdin.write("[");
+    // Wait for pendingBracket to be processed and shown in footer
+    await vi.waitFor(() => {
+      expect(lastFrame()).toContain("[_");
+    });
+    stdin.write("c");
+    await vi.waitFor(() => {
+      const output = lastFrame()!;
+      expect(output).toMatch(/>.*│.*[-+]/);
+    });
+  });
+
+  it("]c does nothing when no change lines ahead", async () => {
+    // Use diffTexts with no changes (identical before/after)
+    const noDiffTexts = new Map([["b1:b2", { before: "line1\nline2", after: "line1\nline2" }]]);
+    const { stdin, lastFrame } = render(
+      <PullRequestDetail
+        pullRequest={pullRequest as any}
+        differences={differences as any}
+        commentThreads={[] as any}
+        diffTexts={noDiffTexts}
+        onBack={vi.fn()}
+        onHelp={vi.fn()}
+        onShowActivity={vi.fn()}
+        comment={{ onPost: vi.fn(), isProcessing: false, error: null, onClearError: vi.fn() }}
+        inlineComment={defaultInlineCommentProps}
+        reply={defaultReplyProps}
+        approval={defaultApprovalProps}
+        merge={defaultMergeProps}
+        close={defaultCloseProps}
+        commitView={defaultCommitProps}
+        editComment={defaultEditCommentProps}
+        deleteComment={defaultDeleteCommentProps}
+        reaction={defaultReactionProps}
+      />,
+    );
+
+    stdin.write("]");
+    await vi.waitFor(() => {
+      expect(lastFrame()).toContain("]_");
+    });
+    stdin.write("c");
+    await vi.waitFor(() => {
+      // After ]c with no changes, footer returns to normal (no pending bracket)
+      expect(lastFrame()).not.toContain("]_");
+    });
+    // Cursor position should be unchanged (still on header line)
+    expect(lastFrame()).toContain("> ");
+    expect(lastFrame()).toContain("src/auth.ts");
+  });
+
+  it("[ + j resets pendingBracket and j moves cursor normally", async () => {
+    const { stdin, lastFrame } = render(
+      <PullRequestDetail
+        pullRequest={pullRequest as any}
+        differences={differences as any}
+        commentThreads={[] as any}
+        diffTexts={diffTexts}
+        onBack={vi.fn()}
+        onHelp={vi.fn()}
+        onShowActivity={vi.fn()}
+        comment={{ onPost: vi.fn(), isProcessing: false, error: null, onClearError: vi.fn() }}
+        inlineComment={defaultInlineCommentProps}
+        reply={defaultReplyProps}
+        approval={defaultApprovalProps}
+        merge={defaultMergeProps}
+        close={defaultCloseProps}
+        commitView={defaultCommitProps}
+        editComment={defaultEditCommentProps}
+        deleteComment={defaultDeleteCommentProps}
+        reaction={defaultReactionProps}
+      />,
+    );
+
+    // Press [ (sets pendingBracket), then j (resets and does normal cursor down)
+    stdin.write("[");
+    await vi.waitFor(() => {
+      expect(lastFrame()).toContain("[_");
+    });
+    stdin.write("j");
+    await vi.waitFor(() => {
+      const output = lastFrame()!;
+      // Cursor should have moved down one line (to separator, the second line)
+      const lines = output.split("\n");
+      const cursorLine = lines.find((l) => l.startsWith(">") || l.includes("> "));
+      // The cursor should be on a line that is NOT the header (first line)
+      expect(cursorLine).toBeTruthy();
+      expect(cursorLine).not.toContain("src/auth.ts");
+    });
+  });
 });

src/components/PullRequestDetail.tsx

@@ -255,6 +255,7 @@ export function PullRequestDetail({
   const [diffLineLimits, setDiffLineLimits] = useState<Map<string, number>>(new Map());
   const [showFileList, setShowFileList] = useState(false);
   const [fileListCursor, setFileListCursor] = useState(0);
+  const [pendingBracket, setPendingBracket] = useState<"[" | "]" | null>(null);
   const diffCacheRef = useRef<Map<string, DisplayLine[]>>(new Map());
 
   useEffect(() => {
@@ -415,6 +416,29 @@ export function PullRequestDetail({
     )
       return;
 
+    // === 2-key sequence: ]c / [c for change navigation ===
+    if (pendingBracket && input === "c") {
+      const isNext = pendingBracket === "]";
+      setPendingBracket(null);
+      if (isNext) {
+        const idx = lines.findIndex(
+          (l, i) => i > cursorIndex && (l.type === "add" || l.type === "delete"),
+        );
+        if (idx !== -1) setCursorIndex(idx);
+      } else {
+        for (let i = cursorIndex - 1; i >= 0; i--) {
+          if (lines[i]!.type === "add" || lines[i]!.type === "delete") {
+            setCursorIndex(i);
+            break;
+          }
+        }
+      }
+      return;
+    }
+    if (pendingBracket) {
+      setPendingBracket(null);
+    }
+
     if (key.tab && (commits.length > 0 || commitsAvailable)) {
       if (commits.length === 0) {
         // Lazy load: trigger first commit load
@@ -599,6 +623,14 @@ export function PullRequestDetail({
       setReactionTarget(currentLine.commentId);
       return;
     }
+    if (input === "]") {
+      setPendingBracket("]");
+      return;
+    }
+    if (input === "[") {
+      setPendingBracket("[");
+      return;
+    }
   });
 
   const scrollOffset = useMemo(() => {
@@ -901,11 +933,13 @@ export function PullRequestDetail({
           reactionTarget ||
           showFileList
             ? ""
-            : viewIndex === -1 && (commits.length > 0 || commitsAvailable)
-              ? `Tab view ↑↓ n/N file f list c comment C inline R reply o fold e edit d del g react a/r approve m merge x close A activity q ? help${hasTruncation ? " t more" : ""}`
-              : viewIndex >= 0
-                ? "Tab next Shift+Tab prev ↑↓ e edit d del a/r approve m merge x close q ? help"
-                : `↑↓ n/N file f list c comment C inline R reply o fold e edit d del g react a/r approve m merge x close A activity q ? help${hasTruncation ? " t more" : ""}`}
+            : pendingBracket
+              ? `${pendingBracket}_ Press c for ${pendingBracket === "]" ? "next" : "previous"} change, other key to cancel`
+              : viewIndex === -1 && (commits.length > 0 || commitsAvailable)
+                ? `Tab view ↑↓ n/N file ]c/[c change f list c comment C inline R reply o fold e edit d del g react a/r approve m merge x close A activity q ? help${hasTruncation ? " t more" : ""}`
+                : viewIndex >= 0
+                  ? "Tab next Shift+Tab prev ↑↓ ]c/[c change e edit d del a/r approve m merge x close q ? help"
+                  : `↑↓ n/N file ]c/[c change f list c comment C inline R reply o fold e edit d del g react a/r approve m merge x close A activity q ? help${hasTruncation ? " t more" : ""}`}
         </Text>
       </Box>
     </Box>