Open message links externally

apps/desktop/electron/main.ts

@@ -91,6 +91,38 @@ const appIconPath = app.isPackaged
   : path.join(__dirname, "..", "..", "resources", "icon.png");
 const appIcon = nativeImage.createFromPath(appIconPath);
 
+function parseWebUrl(url: string): URL | null {
+  try {
+    const parsed = new URL(url);
+    return ["http:", "https:"].includes(parsed.protocol) ? parsed : null;
+  } catch {
+    return null;
+  }
+}
+
+function isInAppUrl(url: string): boolean {
+  try {
+    const parsed = new URL(url);
+    if (isDev && process.env.ELECTRON_RENDERER_URL) {
+      return parsed.origin === new URL(process.env.ELECTRON_RENDERER_URL).origin;
+    }
+    return parsed.protocol === "file:";
+  } catch {
+    return false;
+  }
+}
+
+function openExternalWebUrl(url: string): boolean {
+  const parsed = parseWebUrl(url);
+  if (!parsed) {
+    return false;
+  }
+  void shell.openExternal(parsed.toString()).catch((error) => {
+    console.error(`Failed to open external URL: ${parsed.toString()}`, error);
+  });
+  return true;
+}
+
 function readClipboardImageAttachment(): ComposerImageAttachment | null {
   const image = clipboard.readImage();
   if (image.isEmpty()) {
@@ -141,6 +173,20 @@ function createWindow(): BrowserWindow {
     },
   });
 
+  window.webContents.setWindowOpenHandler(({ url }) => {
+    if (!isInAppUrl(url)) {
+      openExternalWebUrl(url);
+    }
+    return { action: "deny" };
+  });
+  window.webContents.on("will-navigate", (event, url) => {
+    if (isInAppUrl(url)) {
+      return;
+    }
+    event.preventDefault();
+    openExternalWebUrl(url);
+  });
+
   window.once("ready-to-show", () => {
     if (!backgroundTestMode) {
       window.show();
@@ -488,11 +534,11 @@ app.whenReady().then(async () => {
     return mode;
   });
   ipcMain.handle(desktopIpc.openExternal, (_event, url: string) => {
-    const parsed = new URL(url);
-    if (!["http:", "https:"].includes(parsed.protocol)) {
+    const parsed = parseWebUrl(url);
+    if (!parsed) {
       throw new Error(`Refusing to open unsupported URL: ${url}`);
     }
-    return shell.openExternal(url);
+    return shell.openExternal(parsed.toString());
   });
   ipcMain.handle(desktopIpc.stateRequest, () => store.getState());
   ipcMain.handle(desktopIpc.selectedTranscriptRequest, () => store.getSelectedTranscript());

apps/desktop/tests/core/external-links.spec.ts

@@ -0,0 +1,59 @@
+import { join } from "node:path";
+import { expect, test } from "@playwright/test";
+import {
+  launchDesktop,
+  makeUserDataDir,
+  makeWorkspace,
+  seedAgentDir,
+  seedExternalLinkSessionFixture,
+  selectSession,
+} from "../helpers/electron-app";
+
+test("opens markdown web links externally without leaving the current session", async () => {
+  test.setTimeout(60_000);
+  const userDataDir = await makeUserDataDir();
+  const agentDir = join(userDataDir, "agent");
+  const workspacePath = await makeWorkspace("external-links-workspace");
+  const targetUrl = "https://github.com/minghinmatthewlam/pi-gui/issues/20";
+  await seedAgentDir(agentDir);
+  await seedExternalLinkSessionFixture(agentDir, workspacePath);
+
+  const harness = await launchDesktop(userDataDir, {
+    agentDir,
+    initialWorkspaces: [workspacePath],
+    testMode: "background",
+  });
+
+  try {
+    const window = await harness.firstWindow();
+    await selectSession(window, "External link fixture session");
+    const appUrl = window.url();
+
+    await harness.electronApp.evaluate(({ shell }) => {
+      const globals = globalThis as typeof globalThis & { __piGuiOpenedExternalUrls?: string[] };
+      globals.__piGuiOpenedExternalUrls = [];
+      shell.openExternal = async (url: string) => {
+        globals.__piGuiOpenedExternalUrls?.push(url);
+      };
+    });
+
+    await window.getByRole("link", { name: "GitHub issue" }).click();
+
+    await expect
+      .poll(() =>
+        harness.electronApp.evaluate(
+          () =>
+            (globalThis as typeof globalThis & { __piGuiOpenedExternalUrls?: string[] })
+              .__piGuiOpenedExternalUrls ?? [],
+        ),
+      )
+      .toEqual([targetUrl]);
+    await expect
+      .poll(() => harness.electronApp.evaluate(({ BrowserWindow }) => BrowserWindow.getAllWindows().length))
+      .toBe(1);
+    expect(window.url()).toBe(appUrl);
+    await expect(window.getByTestId("transcript")).toContainText("GitHub issue");
+  } finally {
+    await harness.close();
+  }
+});

apps/desktop/tests/helpers/electron-app.ts

@@ -634,6 +634,52 @@ export async function seedToolResultTreeSessionFixture(
   });
 }
 
+export async function seedExternalLinkSessionFixture(
+  agentDir: string,
+  workspacePath: string,
+): Promise<{
+  readonly sessionId: string;
+  readonly title: "External link fixture session";
+}> {
+  const { SessionManager } = (await import(
+    "../../../../node_modules/@earendil-works/pi-coding-agent/dist/core/session-manager.js"
+  )) as {
+    SessionManager: {
+      create(cwd: string): {
+        appendMessage(message: { role: "user" | "assistant"; content: string; timestamp: number }): string;
+        appendSessionInfo(name: string): string;
+        getSessionId(): string;
+      };
+    };
+  };
+
+  return withAgentDirEnv(agentDir, async () => {
+    const sessionManager = SessionManager.create(workspacePath);
+    let timestamp = Date.now();
+    const nextTimestamp = () => {
+      timestamp += 1_000;
+      return timestamp;
+    };
+
+    sessionManager.appendMessage({
+      role: "user",
+      content: "Show me the related issue.",
+      timestamp: nextTimestamp(),
+    });
+    sessionManager.appendMessage({
+      role: "assistant",
+      content: "Track this in [GitHub issue](https://github.com/minghinmatthewlam/pi-gui/issues/20).",
+      timestamp: nextTimestamp(),
+    });
+    sessionManager.appendSessionInfo("External link fixture session");
+
+    return {
+      sessionId: sessionManager.getSessionId(),
+      title: "External link fixture session",
+    };
+  });
+}
+
 async function withAgentDirEnv<T>(agentDir: string, action: () => Promise<T>): Promise<T> {
   const previousAgentDir = process.env.PI_CODING_AGENT_DIR;
   process.env.PI_CODING_AGENT_DIR = agentDir;