feat: add reload shortcut for the current diff

src/ui/App.tsx

@@ -55,6 +55,37 @@ function clamp(value: number, min: number, max: number) {
   return Math.min(Math.max(value, min), max);
 }
 
+/** Return whether the current input can be reloaded from disk or Git state. */
+function canRefreshInput(input: CliInput) {
+  return input.kind !== "patch" || Boolean(input.file && input.file !== "-");
+}
+
+/** Preserve the active shell view settings when rebuilding the current input. */
+function withCurrentViewOptions(
+  input: CliInput,
+  view: {
+    layoutMode: LayoutMode;
+    themeId: string;
+    showAgentNotes: boolean;
+    showHunkHeaders: boolean;
+    showLineNumbers: boolean;
+    wrapLines: boolean;
+  },
+): CliInput {
+  return {
+    ...input,
+    options: {
+      ...input.options,
+      mode: view.layoutMode,
+      theme: view.themeId,
+      agentNotes: view.showAgentNotes,
+      hunkHeaders: view.showHunkHeaders,
+      lineNumbers: view.showLineNumbers,
+      wrapLines: view.wrapLines,
+    },
+  };
+}
+
 /** Orchestrate global app state, layout, navigation, and pane coordination. */
 function AppShell({
   bootstrap,
@@ -321,6 +352,38 @@ function AppShell({
     jumpToFile(fileId, hunkIndex);
   };
 
+  const canRefreshCurrentInput = canRefreshInput(bootstrap.input);
+
+  /** Rebuild the current diff source while preserving the active shell view options. */
+  const refreshCurrentInput = useCallback(() => {
+    if (!canRefreshCurrentInput) {
+      return;
+    }
+
+    const nextInput = withCurrentViewOptions(bootstrap.input, {
+      layoutMode,
+      themeId,
+      showAgentNotes,
+      showHunkHeaders,
+      showLineNumbers,
+      wrapLines,
+    });
+
+    void onReloadSession(nextInput).catch((error) => {
+      console.error("Failed to reload the current diff.", error);
+    });
+  }, [
+    bootstrap.input,
+    canRefreshCurrentInput,
+    layoutMode,
+    onReloadSession,
+    showAgentNotes,
+    showHunkHeaders,
+    showLineNumbers,
+    themeId,
+    wrapLines,
+  ]);
+
   /** Leave the app through the shell-owned shutdown path. */
   const requestQuit = useCallback(() => {
     onQuit();
@@ -330,11 +393,13 @@ function AppShell({
     () =>
       buildAppMenus({
         activeThemeId: activeTheme.id,
+        canRefreshCurrentInput,
         focusFiles: () => setFocusArea("files"),
         focusFilter: () => setFocusArea("filter"),
         layoutMode,
         moveAnnotatedFile,
         moveHunk,
+        refreshCurrentInput,
         requestQuit,
         selectLayoutMode: setLayoutMode,
         selectThemeId: setThemeId,
@@ -353,9 +418,11 @@ function AppShell({
       }),
     [
       activeTheme.id,
+      canRefreshCurrentInput,
       layoutMode,
       moveAnnotatedFile,
       moveHunk,
+      refreshCurrentInput,
       requestQuit,
       showAgentNotes,
       showHelp,
@@ -645,6 +712,12 @@ function AppShell({
       return;
     }
 
+    if ((key.name === "r" || key.sequence === "r") && canRefreshCurrentInput) {
+      refreshCurrentInput();
+      closeMenu();
+      return;
+    }
+
     if (key.name === "t") {
       const currentIndex = THEMES.findIndex((theme) => theme.id === activeTheme.id);
       const nextIndex = (currentIndex + 1) % THEMES.length;
@@ -785,6 +858,7 @@ function AppShell({
 
       {!pagerMode ? (
         <StatusBar
+          canRefresh={canRefreshCurrentInput}
           canResizeDivider={showFilesPane}
           filter={filter}
           filterFocused={focusArea === "filter"}
@@ -817,6 +891,7 @@ function AppShell({
       {!pagerMode && showHelp ? (
         <Suspense fallback={null}>
           <LazyHelpDialog
+            canRefresh={canRefreshCurrentInput}
             left={helpLeft}
             theme={activeTheme}
             width={helpWidth}

src/ui/components/chrome/HelpDialog.tsx

@@ -2,11 +2,13 @@ import type { AppTheme } from "../../themes";
 
 /** Render the compact keyboard help overlay. */
 export function HelpDialog({
+  canRefresh = false,
   left,
   theme,
   width,
   onClose,
 }: {
+  canRefresh?: boolean;
   left: number;
   theme: AppTheme;
   width: number;
@@ -19,7 +21,7 @@ export function HelpDialog({
         top: 3,
         left,
         width,
-        height: 9,
+        height: canRefresh ? 10 : 9,
         zIndex: 60,
         border: true,
         borderColor: theme.accent,
@@ -33,6 +35,7 @@ export function HelpDialog({
       <text fg={theme.text}>Keyboard</text>
       <text fg={theme.muted}>F10 menus arrows navigate menus Enter select Esc close menu</text>
       <text fg={theme.muted}>1 split 2 stack 0 auto t theme a notes l lines w wrap m meta</text>
+      {canRefresh ? <text fg={theme.muted}>r reload the current diff</text> : null}
       <text fg={theme.muted}>
         ↑/↓ line scroll space next page b previous page Home/End jump [ previous hunk ] next hunk
       </text>

src/ui/components/chrome/StatusBar.tsx

@@ -3,6 +3,7 @@ import { fitText } from "../../lib/text";
 
 /** Render either keyboard hints or the active file filter input. */
 export function StatusBar({
+  canRefresh = false,
   canResizeDivider = false,
   filter,
   filterFocused,
@@ -12,6 +13,7 @@ export function StatusBar({
   onFilterInput,
   onFilterSubmit,
 }: {
+  canRefresh?: boolean;
   canResizeDivider?: boolean;
   filter: string;
   filterFocused: boolean;
@@ -25,6 +27,9 @@ export function StatusBar({
   if (canResizeDivider) {
     hintParts.push("drag divider resize");
   }
+  if (canRefresh) {
+    hintParts.push("r reload");
+  }
   hintParts.push(
     "↑↓ line",
     "space/b page",

src/ui/lib/appMenus.ts

@@ -4,11 +4,13 @@ import { THEMES } from "../themes";
 
 export interface BuildAppMenusOptions {
   activeThemeId: string;
+  canRefreshCurrentInput: boolean;
   focusFiles: () => void;
   focusFilter: () => void;
   layoutMode: LayoutMode;
   moveAnnotatedFile: (delta: number) => void;
   moveHunk: (delta: number) => void;
+  refreshCurrentInput: () => void;
   requestQuit: () => void;
   selectLayoutMode: (mode: LayoutMode) => void;
   selectThemeId: (themeId: string) => void;
@@ -29,11 +31,13 @@ export interface BuildAppMenusOptions {
 /** Build the top-level app menus from the current shell state and actions. */
 export function buildAppMenus({
   activeThemeId,
+  canRefreshCurrentInput,
   focusFiles,
   focusFilter,
   layoutMode,
   moveAnnotatedFile,
   moveHunk,
+  refreshCurrentInput,
   requestQuit,
   selectLayoutMode,
   selectThemeId,
@@ -57,28 +61,42 @@ export function buildAppMenus({
     action: () => selectThemeId(theme.id),
   }));
 
+  const fileMenuEntries: MenuEntry[] = [
+    {
+      kind: "item",
+      label: "Focus files",
+      hint: "Tab",
+      action: focusFiles,
+    },
+    {
+      kind: "item",
+      label: "Focus filter",
+      hint: "/",
+      action: focusFilter,
+    },
+  ];
+
+  if (canRefreshCurrentInput) {
+    fileMenuEntries.push({
+      kind: "item",
+      label: "Reload",
+      hint: "r",
+      action: refreshCurrentInput,
+    });
+  }
+
+  fileMenuEntries.push(
+    { kind: "separator" },
+    {
+      kind: "item",
+      label: "Quit",
+      hint: "q",
+      action: requestQuit,
+    },
+  );
+
   return {
-    file: [
-      {
-        kind: "item",
-        label: "Focus files",
-        hint: "Tab",
-        action: focusFiles,
-      },
-      {
-        kind: "item",
-        label: "Focus filter",
-        hint: "/",
-        action: focusFilter,
-      },
-      { kind: "separator" },
-      {
-        kind: "item",
-        label: "Quit",
-        hint: "q",
-        action: requestQuit,
-      },
-    ],
+    file: fileMenuEntries,
     view: [
       {
         kind: "item",

test/app-interactions.test.tsx

@@ -1,9 +1,13 @@
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
 import { describe, expect, mock, test } from "bun:test";
 import { testRender } from "@opentui/react/test-utils";
 import { parseDiffFromFile } from "@pierre/diffs";
 import { act } from "react";
 import type { AppBootstrap, DiffFile, LayoutMode } from "../src/core/types";
 
+const { loadAppBootstrap } = await import("../src/core/loaders");
 const { App } = await import("../src/ui/App");
 
 function createDiffFile(
@@ -352,6 +356,7 @@ describe("App interactions", () => {
       }
 
       expect(frame).toContain("Focus files");
+      expect(frame).toContain("Reload");
       expect(frame).toContain("Quit");
 
       await act(async () => {
@@ -377,6 +382,60 @@ describe("App interactions", () => {
     }
   });
 
+  test("reload shortcut reloads the current file diff from disk", async () => {
+    const dir = mkdtempSync(join(tmpdir(), "hunk-reload-"));
+    const left = join(dir, "before.ts");
+    const right = join(dir, "after.ts");
+
+    writeFileSync(left, "export const answer = 41;\n");
+    writeFileSync(right, "export const answer = 42;\n");
+
+    const bootstrap = await loadAppBootstrap({
+      kind: "diff",
+      left,
+      right,
+      options: {
+        mode: "split",
+      },
+    });
+
+    const setup = await testRender(<App bootstrap={bootstrap} />, {
+      width: 220,
+      height: 20,
+    });
+
+    try {
+      await flush(setup);
+
+      let frame = setup.captureCharFrame();
+      expect(frame).not.toContain("export const added = true;");
+
+      writeFileSync(right, "export const answer = 42;\nexport const added = true;\n");
+
+      await act(async () => {
+        await setup.mockInput.typeText("r");
+      });
+
+      let refreshed = false;
+      for (let attempt = 0; attempt < 20; attempt += 1) {
+        await flush(setup);
+        frame = setup.captureCharFrame();
+        if (frame.includes("export const added = true;")) {
+          refreshed = true;
+          break;
+        }
+        await Bun.sleep(25);
+      }
+
+      expect(refreshed).toBe(true);
+    } finally {
+      await act(async () => {
+        setup.renderer.destroy();
+      });
+      rmSync(dir, { force: true, recursive: true });
+    }
+  });
+
   test("a shows notes that are visible in the current review viewport", async () => {
     const bootstrap = createBootstrap();
     bootstrap.changeset.files[1]!.agent = {

test/ui-components.test.tsx

@@ -636,13 +636,14 @@ describe("UI components", () => {
   test("HelpDialog renders the keyboard help copy", async () => {
     const theme = resolveTheme("midnight", null);
     const frame = await captureFrame(
-      <HelpDialog left={2} theme={theme} width={68} onClose={() => {}} />,
+      <HelpDialog canRefresh={true} left={2} theme={theme} width={68} onClose={() => {}} />,
       76,
       14,
     );
 
     expect(frame).toContain("Keyboard");
     expect(frame).toContain("F10 menus");
+    expect(frame).toContain("r reload");
     expect(frame).toContain("drag the Files/Diff divider");
   });