fix: sync active file after review filtering

Generated-By: PostHog Code
Task-Id: f774fb55-18e5-4248-acb9-3f9bf3e7d3ee

Author: MattPua

packages/ui/src/features/code-review/commentFileFilter.ts

@@ -62,6 +62,52 @@ export function filterReviewItemsByFilePaths(
   return filteredItems;
 }
 
+export function filterReviewItemsByViewedState(
+  items: ReviewListItem[],
+  currentSignatures: ReadonlyMap<string, string>,
+  viewedRecord: Readonly<Record<string, string>>,
+): ReviewListItem[] {
+  const filteredItems: ReviewListItem[] = [];
+  let pendingSectionItems: ReviewListItem[] = [];
+
+  for (const item of items) {
+    if (!item.filePaths) {
+      pendingSectionItems = [item];
+      continue;
+    }
+
+    const signature = item.scrollKey
+      ? currentSignatures.get(item.scrollKey)
+      : undefined;
+    if (
+      signature !== undefined &&
+      item.scrollKey !== undefined &&
+      viewedRecord[item.scrollKey] === signature
+    ) {
+      continue;
+    }
+
+    filteredItems.push(...pendingSectionItems, item);
+    pendingSectionItems = [];
+  }
+
+  return filteredItems;
+}
+
+export function resolveVisibleActiveFilePath(
+  items: ReviewListItem[],
+  activeFilePath: string | null,
+): string | null {
+  if (
+    activeFilePath &&
+    items.some((item) => item.filePaths?.includes(activeFilePath))
+  ) {
+    return activeFilePath;
+  }
+
+  return items.find((item) => item.scrollKey)?.scrollKey ?? null;
+}
+
 export function deriveCommentFileFilterState({
   items,
   requestedFilter,

packages/ui/src/features/code-review/components/ReviewShell.tsx

@@ -16,8 +16,10 @@ import {
 import { VList, type VListHandle } from "virtua";
 import {
   deriveCommentFileFilterState,
+  filterReviewItemsByViewedState,
   getEmptyReviewMessage,
   type ReviewListItem,
+  resolveVisibleActiveFilePath,
 } from "../commentFileFilter";
 import {
   REVIEW_LIST_BUFFER_PX,
@@ -29,7 +31,6 @@ import { useReviewNavigationStore } from "../reviewNavigationStore";
 import type { ReviewShellProps } from "../reviewShellParts";
 import {
   buildItemIndex,
-  filterReviewItemsByViewedState,
   findActiveScrollKey,
   findRenderedScrollAnchor,
   isFileViewed,
@@ -272,8 +273,28 @@ export function ReviewShell({
   const setActiveFilePath = useReviewNavigationStore(
     (s) => s.setActiveFilePath,
   );
+  const activeFilePath = useReviewNavigationStore(
+    (s) => s.activeFilePaths[taskId] ?? null,
+  );
   const clearTask = useReviewNavigationStore((s) => s.clearTask);
 
+  useEffect(() => {
+    if (!hideViewedFiles || !activeFilePath) return;
+    const nextActiveFilePath = resolveVisibleActiveFilePath(
+      filteredItems,
+      activeFilePath,
+    );
+    if (nextActiveFilePath === activeFilePath) return;
+    lastActiveRef.current = nextActiveFilePath;
+    setActiveFilePath(taskId, nextActiveFilePath);
+  }, [
+    activeFilePath,
+    filteredItems,
+    hideViewedFiles,
+    setActiveFilePath,
+    taskId,
+  ]);
+
   useEffect(() => {
     return () => {
       if (navigationFrameRef.current !== null) {

packages/ui/src/features/code-review/reviewShellParts.test.tsx

@@ -17,13 +17,14 @@ vi.mock("../../primitives/FileIcon", () => ({
 import {
   deriveCommentFileFilterState,
   filterReviewItemsByFilePaths,
+  filterReviewItemsByViewedState,
   getCommentedFilePaths,
   type ReviewListItem,
+  resolveVisibleActiveFilePath,
 } from "./commentFileFilter";
 import {
   DeferredDiffPlaceholder,
   DiffFileHeader,
-  filterReviewItemsByViewedState,
   findActiveScrollKey,
   findRenderedScrollAnchor,
 } from "./reviewShellParts";
@@ -200,6 +201,22 @@ describe("commented file filtering", () => {
     ).toEqual(["section:changes", "unstaged:b.ts"]);
   });
 
+  it("selects the first visible file when the active file is filtered out", () => {
+    const items: ReviewListItem[] = [
+      { key: "section:changes", node: <span>Changes</span> },
+      {
+        key: "b.ts",
+        scrollKey: "b.ts",
+        filePaths: ["b.ts", "old-b.ts"],
+        node: <span>B</span>,
+      },
+    ];
+
+    expect(resolveVisibleActiveFilePath(items, "a.ts")).toBe("b.ts");
+    expect(resolveVisibleActiveFilePath(items, "old-b.ts")).toBe("old-b.ts");
+    expect(resolveVisibleActiveFilePath([], "a.ts")).toBeNull();
+  });
+
   it("collects paths for all and unresolved comment threads", () => {
     const commentedPaths = getCommentedFilePaths(
       new Map([

packages/ui/src/features/code-review/reviewShellParts.tsx

@@ -301,38 +301,6 @@ export function isFileViewed(
   return storedSig === currentSig;
 }
 
-export function filterReviewItemsByViewedState(
-  items: ReviewListItem[],
-  currentSignatures: ReadonlyMap<string, string>,
-  viewedRecord: Readonly<Record<string, string>>,
-): ReviewListItem[] {
-  const filteredItems: ReviewListItem[] = [];
-  let pendingSectionItems: ReviewListItem[] = [];
-
-  for (const item of items) {
-    if (!item.filePaths) {
-      pendingSectionItems = [item];
-      continue;
-    }
-
-    const signature = item.scrollKey
-      ? currentSignatures.get(item.scrollKey)
-      : undefined;
-    if (
-      signature !== undefined &&
-      item.scrollKey !== undefined &&
-      isFileViewed(viewedRecord[item.scrollKey], signature)
-    ) {
-      continue;
-    }
-
-    filteredItems.push(...pendingSectionItems, item);
-    pendingSectionItems = [];
-  }
-
-  return filteredItems;
-}
-
 function ViewedCheckbox({ viewedKey }: { viewedKey: string }) {
   const ctx = useReviewViewedContext();
   if (!ctx) return null;