feat: add side-by-side diff layout and whitespace toggle (#208)

packages/app/src/hooks/use-changes-preferences.test.ts

@@ -0,0 +1,74 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const asyncStorageMock = vi.hoisted(() => ({
+  getItem: vi.fn<(_: string) => Promise<string | null>>(),
+  setItem: vi.fn<(_: string, __: string) => Promise<void>>(),
+}));
+
+vi.mock("@react-native-async-storage/async-storage", () => ({
+  default: asyncStorageMock,
+}));
+
+describe("use-changes-preferences", () => {
+  beforeEach(() => {
+    vi.resetModules();
+    asyncStorageMock.getItem.mockReset();
+    asyncStorageMock.setItem.mockReset();
+  });
+
+  it("defaults to unified layout with visible whitespace", async () => {
+    asyncStorageMock.getItem.mockResolvedValue(null);
+    asyncStorageMock.setItem.mockResolvedValue();
+
+    const mod = await import("./use-changes-preferences");
+    const result = await mod.loadChangesPreferencesFromStorage();
+
+    expect(result).toEqual(mod.DEFAULT_CHANGES_PREFERENCES);
+    expect(asyncStorageMock.setItem).toHaveBeenCalledWith(
+      "@paseo:changes-preferences",
+      JSON.stringify(mod.DEFAULT_CHANGES_PREFERENCES),
+    );
+  });
+
+  it("migrates the legacy wrap-lines toggle into the new preferences object", async () => {
+    asyncStorageMock.getItem.mockImplementation(async (key: string) => {
+      if (key === "diff-wrap-lines") {
+        return "true";
+      }
+      return null;
+    });
+    asyncStorageMock.setItem.mockResolvedValue();
+
+    const mod = await import("./use-changes-preferences");
+    const result = await mod.loadChangesPreferencesFromStorage();
+
+    expect(result).toEqual({
+      layout: "unified",
+      wrapLines: true,
+      hideWhitespace: false,
+    });
+  });
+
+  it("loads persisted layout and whitespace preferences", async () => {
+    asyncStorageMock.getItem.mockImplementation(async (key: string) => {
+      if (key === "@paseo:changes-preferences") {
+        return JSON.stringify({
+          layout: "split",
+          hideWhitespace: true,
+          wrapLines: false,
+        });
+      }
+      return null;
+    });
+
+    const mod = await import("./use-changes-preferences");
+    const result = await mod.loadChangesPreferencesFromStorage();
+
+    expect(result).toEqual({
+      layout: "split",
+      hideWhitespace: true,
+      wrapLines: false,
+    });
+    expect(asyncStorageMock.setItem).not.toHaveBeenCalled();
+  });
+});

packages/app/src/hooks/use-changes-preferences.ts

@@ -0,0 +1,89 @@
+import { useCallback } from "react";
+import AsyncStorage from "@react-native-async-storage/async-storage";
+import { useQuery, useQueryClient } from "@tanstack/react-query";
+import { z } from "zod";
+
+const CHANGES_PREFERENCES_STORAGE_KEY = "@paseo:changes-preferences";
+const LEGACY_WRAP_LINES_STORAGE_KEY = "diff-wrap-lines";
+const CHANGES_PREFERENCES_QUERY_KEY = ["changes-preferences"];
+
+const changesPreferencesSchema = z.object({
+  layout: z.enum(["unified", "split"]).optional(),
+  wrapLines: z.boolean().optional(),
+  hideWhitespace: z.boolean().optional(),
+});
+
+export interface ChangesPreferences {
+  layout: "unified" | "split";
+  wrapLines: boolean;
+  hideWhitespace: boolean;
+}
+
+export const DEFAULT_CHANGES_PREFERENCES: ChangesPreferences = {
+  layout: "unified",
+  wrapLines: false,
+  hideWhitespace: false,
+};
+
+async function loadLegacyWrapLinesPreference(): Promise<boolean | null> {
+  const legacyValue = await AsyncStorage.getItem(LEGACY_WRAP_LINES_STORAGE_KEY);
+  if (legacyValue === "true") {
+    return true;
+  }
+  if (legacyValue === "false") {
+    return false;
+  }
+  return null;
+}
+
+export async function loadChangesPreferencesFromStorage(): Promise<ChangesPreferences> {
+  const stored = await AsyncStorage.getItem(CHANGES_PREFERENCES_STORAGE_KEY);
+  if (stored) {
+    const parsed = changesPreferencesSchema.safeParse(JSON.parse(stored));
+    if (parsed.success) {
+      return { ...DEFAULT_CHANGES_PREFERENCES, ...parsed.data };
+    }
+  }
+
+  const legacyWrapLines = await loadLegacyWrapLinesPreference();
+  const next = {
+    ...DEFAULT_CHANGES_PREFERENCES,
+    ...(legacyWrapLines !== null ? { wrapLines: legacyWrapLines } : {}),
+  } satisfies ChangesPreferences;
+  await AsyncStorage.setItem(CHANGES_PREFERENCES_STORAGE_KEY, JSON.stringify(next));
+  return next;
+}
+
+export interface UseChangesPreferencesReturn {
+  preferences: ChangesPreferences;
+  isLoading: boolean;
+  updatePreferences: (updates: Partial<ChangesPreferences>) => Promise<void>;
+}
+
+export function useChangesPreferences(): UseChangesPreferencesReturn {
+  const queryClient = useQueryClient();
+  const { data, isPending } = useQuery({
+    queryKey: CHANGES_PREFERENCES_QUERY_KEY,
+    queryFn: loadChangesPreferencesFromStorage,
+    staleTime: Infinity,
+    gcTime: Infinity,
+  });
+
+  const updatePreferences = useCallback(
+    async (updates: Partial<ChangesPreferences>) => {
+      const prev =
+        queryClient.getQueryData<ChangesPreferences>(CHANGES_PREFERENCES_QUERY_KEY) ??
+        DEFAULT_CHANGES_PREFERENCES;
+      const next = { ...prev, ...updates };
+      queryClient.setQueryData<ChangesPreferences>(CHANGES_PREFERENCES_QUERY_KEY, next);
+      await AsyncStorage.setItem(CHANGES_PREFERENCES_STORAGE_KEY, JSON.stringify(next));
+    },
+    [queryClient],
+  );
+
+  return {
+    preferences: data ?? DEFAULT_CHANGES_PREFERENCES,
+    isLoading: isPending,
+    updatePreferences,
+  };
+}

packages/app/src/hooks/use-checkout-diff-query.ts

@@ -13,8 +13,9 @@ function checkoutDiffQueryKey(
   cwd: string,
   mode: "uncommitted" | "base",
   baseRef?: string,
+  ignoreWhitespace?: boolean,
 ) {
-  return ["checkoutDiff", serverId, cwd, mode, baseRef ?? ""] as const;
+  return ["checkoutDiff", serverId, cwd, mode, baseRef ?? "", ignoreWhitespace === true] as const;
 }
 
 interface UseCheckoutDiffQueryOptions {
@@ -22,6 +23,7 @@ interface UseCheckoutDiffQueryOptions {
   cwd: string;
   mode: "uncommitted" | "base";
   baseRef?: string;
+  ignoreWhitespace?: boolean;
   enabled?: boolean;
 }
 
@@ -35,12 +37,16 @@ export type HighlightToken = NonNullable<DiffLine["tokens"]>[number];
 function normalizeCheckoutDiffCompare(compare: {
   mode: "uncommitted" | "base";
   baseRef?: string;
-}): { mode: "uncommitted" | "base"; baseRef?: string } {
+  ignoreWhitespace?: boolean;
+}): { mode: "uncommitted" | "base"; baseRef?: string; ignoreWhitespace?: boolean } {
+  const ignoreWhitespace = compare.ignoreWhitespace === true;
   if (compare.mode === "uncommitted") {
-    return { mode: "uncommitted" };
+    return { mode: "uncommitted", ignoreWhitespace };
   }
   const trimmedBaseRef = compare.baseRef?.trim();
-  return trimmedBaseRef ? { mode: "base", baseRef: trimmedBaseRef } : { mode: "base" };
+  return trimmedBaseRef
+    ? { mode: "base", baseRef: trimmedBaseRef, ignoreWhitespace }
+    : { mode: "base", ignoreWhitespace };
 }
 
 export function useCheckoutDiffQuery({
@@ -48,6 +54,7 @@ export function useCheckoutDiffQuery({
   cwd,
   mode,
   baseRef,
+  ignoreWhitespace,
   enabled = true,
 }: UseCheckoutDiffQueryOptions) {
   const queryClient = useQueryClient();
@@ -60,14 +67,15 @@ export function useCheckoutDiffQuery({
   const isOpen = isMobile ? mobileView === "file-explorer" : desktopFileExplorerOpen;
   const hookInstanceId = useId();
   const normalizedCompare = useMemo(
-    () => normalizeCheckoutDiffCompare({ mode, baseRef }),
-    [mode, baseRef],
+    () => normalizeCheckoutDiffCompare({ mode, baseRef, ignoreWhitespace }),
+    [mode, baseRef, ignoreWhitespace],
   );
   const compareMode = normalizedCompare.mode;
   const compareBaseRef = normalizedCompare.baseRef;
+  const compareIgnoreWhitespace = normalizedCompare.ignoreWhitespace;
   const queryKey = useMemo(
-    () => checkoutDiffQueryKey(serverId, cwd, mode, baseRef),
-    [serverId, cwd, mode, baseRef],
+    () => checkoutDiffQueryKey(serverId, cwd, mode, baseRef, compareIgnoreWhitespace),
+    [serverId, cwd, mode, baseRef, compareIgnoreWhitespace],
   );
 
   const query = useQuery({
@@ -79,6 +87,7 @@ export function useCheckoutDiffQuery({
       const payload = await client.getCheckoutDiff(cwd, {
         mode: compareMode,
         baseRef: compareBaseRef,
+        ignoreWhitespace: compareIgnoreWhitespace,
       });
       return {
         ...payload,
@@ -104,6 +113,7 @@ export function useCheckoutDiffQuery({
       cwd,
       compareMode,
       compareBaseRef ?? "",
+      compareIgnoreWhitespace ? "ignore-ws" : "keep-ws",
     ].join(":");
     let cancelled = false;
 
@@ -145,6 +155,7 @@ export function useCheckoutDiffQuery({
         {
           mode: compareMode,
           baseRef: compareBaseRef,
+          ignoreWhitespace: compareIgnoreWhitespace,
         },
         { subscriptionId },
       )
@@ -191,6 +202,7 @@ export function useCheckoutDiffQuery({
     serverId,
     compareMode,
     compareBaseRef,
+    compareIgnoreWhitespace,
     queryKey,
     queryClient,
   ]);