fix(web): expanding hidden diff context works after a diff refresh

apps/web/src/components/diffs/codeViewContextExpansion.browser.test.ts

@@ -0,0 +1,59 @@
+import { CodeView, DEFAULT_THEMES, parsePatchFiles, preloadHighlighter } from "@pierre/diffs";
+import { expect, it, vi } from "vite-plus/test";
+
+const OLD_LINES = Array.from({ length: 60 }, (_, index) => `line ${index + 1}`);
+const NEW_LINES = OLD_LINES.with(0, "changed 1").with(59, "changed 60");
+const PATCH = `diff --git a/notes.txt b/notes.txt
+--- a/notes.txt
++++ b/notes.txt
+@@ -1,4 +1,4 @@
+-line 1
++changed 1
+ line 2
+ line 3
+ line 4
+@@ -57,4 +57,4 @@
+ line 57
+ line 58
+ line 59
+-line 60
++changed 60
+`;
+
+function parsePartialDiff() {
+  return parsePatchFiles(PATCH, { cacheKeyPrefix: "notes" })[0]!.files[0]!;
+}
+
+// A diff refresh re-parses an unchanged patch into a new object with the same cacheKey.
+// Upstream keeps rendering the old object and then discards the file contents loaded for it.
+it("expands hidden context after the host re-supplies an unchanged partial diff", async () => {
+  await preloadHighlighter({ themes: Object.values(DEFAULT_THEMES), langs: ["text"] });
+  const root = document.createElement("div");
+  root.style.cssText = "width: 800px; height: 600px; overflow: auto;";
+  document.body.append(root);
+  const view = new CodeView<undefined>({
+    diffStyle: "unified",
+    loadDiffFiles: async () => ({
+      oldFile: { name: "notes.txt", contents: `${OLD_LINES.join("\n")}\n` },
+      newFile: { name: "notes.txt", contents: `${NEW_LINES.join("\n")}\n` },
+    }),
+  });
+  using _view = {
+    [Symbol.dispose]: () => {
+      view.cleanUp();
+      root.remove();
+    },
+  };
+  view.setup(root);
+  const shadowRoot = () => root.querySelector("diffs-container")?.shadowRoot;
+  const lines = () =>
+    Array.from(shadowRoot()?.querySelectorAll("[data-line]") ?? [], (line) => line.textContent);
+
+  view.setItems([{ id: "notes", type: "diff", fileDiff: parsePartialDiff(), version: 1 }]);
+  await vi.waitFor(() => expect(lines()).toContain("line 57"));
+  view.setItems([{ id: "notes", type: "diff", fileDiff: parsePartialDiff(), version: 2 }]);
+
+  shadowRoot()!.querySelector<HTMLElement>("[data-expand-button]")!.click();
+
+  await vi.waitFor(() => expect(lines()).toContain("line 30"));
+});

patches/@pierre__diffs@1.7.0-beta.3.patch

@@ -218,10 +218,20 @@ index 734ff9862cdfe65b8082599c6c221c4886436e01..f18798a3d56dd0749550b5aff62a06fb
  			} catch (error) {
  				if (disableErrorHandling) throw error;
 diff --git a/dist/components/VirtualizedFileDiff.js b/dist/components/VirtualizedFileDiff.js
-index 984f049ff3694dd353fa6637b0f09fc7dce74992..8f659c06b70ba603f725cccdcaebe89c21b00f6b 100644
+index 984f049ff3694dd353fa6637b0f09fc7dce74992..4d6599905be0fe7b5b5c1a225c0b3ff8d810c72a 100644
 --- a/dist/components/VirtualizedFileDiff.js
 +++ b/dist/components/VirtualizedFileDiff.js
-@@ -626,7 +626,7 @@ var VirtualizedFileDiff = class extends FileDiff {
+@@ -264,7 +264,8 @@ var VirtualizedFileDiff = class extends FileDiff {
+ 		const { pendingExpansions, pendingHydratedDiff, options: { collapsed = false } } = this;
+ 		if (pendingHydratedDiff != null) {
+ 			this.pendingHydratedDiff = void 0;
+-			if (pendingHydratedDiff.expectedDiff === fileDiff) {
++			// T3 patch: a host may re-supply an unchanged diff as a new object; it is still this diff.
++			if (areDiffTargetsEqual(pendingHydratedDiff.expectedDiff, fileDiff)) {
+ 				Object.assign(fileDiff, pendingHydratedDiff.nextDiff);
+ 				this.setHydratedState(pendingHydratedDiff.files);
+ 				this.installHydratedDiff(fileDiff);
+@@ -626,7 +627,7 @@ var VirtualizedFileDiff = class extends FileDiff {
  	rerender() {
  		if (!this.enabled || this.getInputDiff() == null && this.additionFile == null && this.deletionFile == null) return;
  		const workingDiff = this.getWorkingDiff();
@@ -230,7 +240,7 @@ index 984f049ff3694dd353fa6637b0f09fc7dce74992..8f659c06b70ba603f725cccdcaebe89c
  		if (this.isSimpleMode()) this.pendingRender = void 0;
  		this.forceRenderOverride = true;
  		if (this.isSimpleMode() && this.requestRender()) return;
-@@ -790,7 +790,7 @@ var VirtualizedFileDiff = class extends FileDiff {
+@@ -790,7 +791,7 @@ var VirtualizedFileDiff = class extends FileDiff {
  		const previousRenderedDiff = this.getRenderedDiff();
  		const { pendingRender } = this;
  		const previousLayoutDiff = pendingRender?.diff ?? previousRenderedDiff;