fix(coding-agent): strip trailing index.js|ts from extension labels in startup banner (#3596)

Strip `index.ts` and `index.js` from extension display paths in both
compact and expanded views of the startup banner. This makes the list more
readable by removing redundant filename noise.

Changes:
- Add `formatExtensionDisplayPath()` helper to centralize path formatting
- Update `getCompactExtensionLabels()` to strip index files from segments
- Update expanded view formatting to use the new helper
- Add comprehensive tests for both views

Fixes #3549
Fixes #3559

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -910,6 +910,12 @@ export class InteractiveMode {
 		return result;
 	}
 
+	private formatExtensionDisplayPath(path: string): string {
+		let result = this.formatDisplayPath(path);
+		result = result.replace(/\/index\.ts$/, "").replace(/\/index\.js$/, "");
+		return result;
+	}
+
 	private formatContextPath(p: string): string {
 		const cwd = path.resolve(this.sessionManager.getCwd());
 		const absolutePath = path.isAbsolute(p) ? path.resolve(p) : path.resolve(cwd, p);
@@ -1044,11 +1050,18 @@ export class InteractiveMode {
 
 	private getCompactExtensionLabels(extensions: Array<{ path: string; sourceInfo?: SourceInfo }>): string[] {
 		const nonPackageExtensions = extensions
-			.map((extension) => ({
+			.map((extension) => {
-				path: extension.path,
+				const segments = this.getCompactDisplayPathSegments(extension.path);
-				sourceInfo: extension.sourceInfo,
+				const lastSegment = segments[segments.length - 1];
-				segments: this.getCompactDisplayPathSegments(extension.path),
+				if (segments.length > 1 && (lastSegment === "index.ts" || lastSegment === "index.js")) {
-			}))
+					segments.pop();
+				}
+				return {
+					path: extension.path,
+					sourceInfo: extension.sourceInfo,
+					segments,
+				};
+			})
 			.filter((extension) => !this.isPackageSource(extension.sourceInfo));
 
 		return extensions.map((extension) => {
@@ -1373,8 +1386,9 @@ export class InteractiveMode {
 			if (extensions.length > 0) {
 				const groups = this.buildScopeGroups(extensions);
 				const extList = this.formatScopeGroups(groups, {
-					formatPath: (item) => this.formatDisplayPath(item.path),
+					formatPath: (item) => this.formatExtensionDisplayPath(item.path),
-					formatPackagePath: (item) => this.getShortPath(item.path, item.sourceInfo),
+					formatPackagePath: (item) =>
+						this.formatExtensionDisplayPath(this.getShortPath(item.path, item.sourceInfo)),
 				});
 				const extensionCompactList = formatCompactList(this.getCompactExtensionLabels(extensions));
 				addLoadedSection("Extensions", extensionCompactList, extList, "mdHeading");

packages/coding-agent/test/interactive-mode-status.test.ts

@@ -262,6 +262,8 @@ describe("InteractiveMode.showLoadedResources", () => {
 				},
 			},
 			formatDisplayPath: (p: string) => (InteractiveMode as any).prototype.formatDisplayPath.call(fakeThis, p),
+			formatExtensionDisplayPath: (p: string) =>
+				(InteractiveMode as any).prototype.formatExtensionDisplayPath.call(fakeThis, p),
 			formatContextPath: (p: string) => (InteractiveMode as any).prototype.formatContextPath.call(fakeThis, p),
 			getStartupExpansionState: () => (InteractiveMode as any).prototype.getStartupExpansionState.call(fakeThis),
 			buildScopeGroups: () => [],
@@ -482,7 +484,7 @@ describe("InteractiveMode.showLoadedResources", () => {
 
 		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
 "[Extensions]
-  @scope/pi-scoped, answer.ts, cli-extension.ts, HazAT/pi-interactive-subagents, HazAT/pi-interactive-subagents:subagents, local-index/index.ts, pi-markdown-preview, user-index/index.ts"`);
+  @scope/pi-scoped, answer.ts, cli-extension.ts, HazAT/pi-interactive-subagents, HazAT/pi-interactive-subagents:subagents, local-index, pi-markdown-preview, user-index"`);
 	});
 
 	test("adds more parent folders until local extension labels are unique", () => {
@@ -528,9 +530,231 @@ describe("InteractiveMode.showLoadedResources", () => {
 
 		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
 "[Extensions]
-  alpha/one/index.ts, beta/one/index.ts, gamma/one/index.ts"`);
+  alpha/one, beta/one, gamma/one"`);
 	});
 
+	test("strips index.ts from local extension label, showing parent dir", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/extensions/plan-mode/index.ts",
+				sourceInfo: createSourceInfo("/tmp/extensions/plan-mode/index.ts", {
+					source: "local",
+					scope: "project",
+					origin: "top-level",
+					baseDir: "/tmp/extensions",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  plan-mode"`);
+	});
+
+	test("strips index.js from local extension label, showing parent dir", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/extensions/plan-mode/index.js",
+				sourceInfo: createSourceInfo("/tmp/extensions/plan-mode/index.js", {
+					source: "local",
+					scope: "project",
+					origin: "top-level",
+					baseDir: "/tmp/extensions",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  plan-mode"`);
+	});
+
+	test("mixed single-file and subdirectory index.ts extensions strip index.ts", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/extensions/webfetch.ts",
+				sourceInfo: createSourceInfo("/tmp/extensions/webfetch.ts", {
+					source: "local",
+					scope: "project",
+					origin: "top-level",
+					baseDir: "/tmp/extensions",
+				}),
+			},
+			{
+				path: "/tmp/extensions/plan-mode/index.ts",
+				sourceInfo: createSourceInfo("/tmp/extensions/plan-mode/index.ts", {
+					source: "local",
+					scope: "project",
+					origin: "top-level",
+					baseDir: "/tmp/extensions",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  plan-mode, webfetch.ts"`);
+	});
+
+	test("multiple index.ts with unique parent dirs need no disambiguation", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/extensions/foo/index.ts",
+				sourceInfo: createSourceInfo("/tmp/extensions/foo/index.ts", {
+					source: "local",
+					scope: "project",
+					origin: "top-level",
+					baseDir: "/tmp/extensions",
+				}),
+			},
+			{
+				path: "/tmp/extensions/bar/index.ts",
+				sourceInfo: createSourceInfo("/tmp/extensions/bar/index.ts", {
+					source: "local",
+					scope: "project",
+					origin: "top-level",
+					baseDir: "/tmp/extensions",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  bar, foo"`);
+	});
+
+	test("multiple index.ts with same parent dir name disambiguated with grandparent", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/alpha/tools/index.ts",
+				sourceInfo: createSourceInfo("/tmp/alpha/tools/index.ts", {
+					source: "cli",
+					scope: "temporary",
+					origin: "top-level",
+					baseDir: "/tmp/alpha",
+				}),
+			},
+			{
+				path: "/tmp/beta/tools/index.ts",
+				sourceInfo: createSourceInfo("/tmp/beta/tools/index.ts", {
+					source: "cli",
+					scope: "temporary",
+					origin: "top-level",
+					baseDir: "/tmp/beta",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  alpha/tools, beta/tools"`);
+	});
+
+	test("non-index file in subdirectory stays as filename", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/extensions/my-ext/main.ts",
+				sourceInfo: createSourceInfo("/tmp/extensions/my-ext/main.ts", {
+					source: "local",
+					scope: "project",
+					origin: "top-level",
+					baseDir: "/tmp/extensions",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  main.ts"`);
+	});
+
+	test("package extensions still strip index.ts correctly (regression guard)", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/project/.pi/npm/node_modules/pi-markdown-preview/extensions/index.ts",
+				sourceInfo: createSourceInfo("/tmp/project/.pi/npm/node_modules/pi-markdown-preview/extensions/index.ts", {
+					source: "npm:pi-markdown-preview",
+					scope: "project",
+					origin: "package",
+					baseDir: "/tmp/project/.pi/npm/node_modules/pi-markdown-preview",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.chatContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  pi-markdown-preview"`);
+	});
 	test("captures mixed extension layouts in expanded output", () => {
 		const fakeThis = createShowLoadedResourcesThis({
 			quietStartup: false,
@@ -547,16 +771,16 @@ describe("InteractiveMode.showLoadedResources", () => {
 "[Extensions]
   project
     /tmp/project/.pi/extensions/answer.ts
-    /tmp/project/.pi/extensions/local-index/index.ts
+    /tmp/project/.pi/extensions/local-index
     git:github.com/HazAT/pi-interactive-subagents
-      extensions/index.ts
+      extensions
-      extensions/subagents/index.ts
+      extensions/subagents
     npm:@scope/pi-scoped
-      extensions/index.ts
+      extensions
     npm:pi-markdown-preview
-      extensions/index.ts
+      extensions
   user
-    /tmp/agent/extensions/user-index/index.ts
+    /tmp/agent/extensions/user-index
   path
     /tmp/temp/cli-extension.ts"`);
 	});