feat: persist diff preferences (#188)

closes https://github.com/better-auth/better-hub/issues/184

apps/web/src/components/pr/pr-diff-viewer.tsx

@@ -61,6 +61,7 @@ import { ClientMarkdown } from "@/components/shared/client-markdown";
 import { CheckStatusBadge } from "@/components/pr/check-status-badge";
 import { useMutationEvents } from "@/components/shared/mutation-event-provider";
 import { UserTooltip } from "@/components/shared/user-tooltip";
+import { getDiffPreferences, setSplitView, setWordWrap } from "@/lib/diff-preferences";
 
 interface DiffFile {
 	filename: string;
@@ -158,8 +159,8 @@ export function PRDiffViewer({
 		}
 		return 0;
 	});
-	const [wordWrap, setWordWrap] = useState(true);
-	const [splitView, setSplitView] = useState(false);
+	const [wordWrap, setWordWrapState] = useState(() => getDiffPreferences().wordWrap);
+	const [splitView, setSplitViewState] = useState(() => getDiffPreferences().splitView);
 	const [sidebarWidth, setSidebarWidth] = useState(220);
 	const [sidebarCollapsed, setSidebarCollapsed] = useState(false);
 	const [isDragging, setIsDragging] = useState(false);
@@ -543,8 +544,18 @@ export function PRDiffViewer({
 						total={files.length}
 						wordWrap={wordWrap}
 						splitView={splitView}
-						onToggleWrap={() => setWordWrap((w) => !w)}
-						onToggleSplit={() => setSplitView((s) => !s)}
+						onToggleWrap={() => {
+							setWordWrapState((w) => {
+								setWordWrap(!w);
+								return !w;
+							});
+						}}
+						onToggleSplit={() => {
+							setSplitViewState((s) => {
+								setSplitView(!s);
+								return !s;
+							});
+						}}
 						sidebarCollapsed={sidebarCollapsed}
 						onToggleSidebar={() =>
 							setSidebarCollapsed((c) => !c)

apps/web/src/lib/diff-preferences.ts

@@ -0,0 +1,43 @@
+const STORAGE_KEY = "better-github-diff-preferences";
+
+export interface DiffPreferences {
+	splitView: boolean;
+	wordWrap: boolean;
+}
+
+const DEFAULT_PREFERENCES: DiffPreferences = {
+	splitView: false,
+	wordWrap: true,
+};
+
+export function getDiffPreferences(): DiffPreferences {
+	if (typeof window === "undefined") return DEFAULT_PREFERENCES;
+	try {
+		const raw = localStorage.getItem(STORAGE_KEY);
+		if (!raw) return DEFAULT_PREFERENCES;
+		const parsed = JSON.parse(raw) as Partial<DiffPreferences>;
+		return { ...DEFAULT_PREFERENCES, ...parsed };
+	} catch {
+		return DEFAULT_PREFERENCES;
+	}
+}
+
+export function setDiffPreferences(prefs: Partial<DiffPreferences>): DiffPreferences {
+	if (typeof window === "undefined") return DEFAULT_PREFERENCES;
+	try {
+		const current = getDiffPreferences();
+		const updated = { ...current, ...prefs };
+		localStorage.setItem(STORAGE_KEY, JSON.stringify(updated));
+		return updated;
+	} catch {
+		return getDiffPreferences();
+	}
+}
+
+export function setSplitView(splitView: boolean): void {
+	setDiffPreferences({ splitView });
+}
+
+export function setWordWrap(wordWrap: boolean): void {
+	setDiffPreferences({ wordWrap });
+}