refactor(browser): share playwright download wait/save flow

Author: steipete

src/browser/pw-tools-core.downloads.ts

@@ -102,6 +102,42 @@ function createPageDownloadWaiter(page: Page, timeoutMs: number) {
   };
 }
 
+type DownloadPayload = {
+  url?: () => string;
+  suggestedFilename?: () => string;
+  saveAs?: (outPath: string) => Promise<void>;
+};
+
+async function saveDownloadPayload(download: DownloadPayload, outPath: string) {
+  const suggested = download.suggestedFilename?.() || "download.bin";
+  const resolvedOutPath = outPath?.trim() || buildTempDownloadPath(suggested);
+  await fs.mkdir(path.dirname(resolvedOutPath), { recursive: true });
+  await download.saveAs?.(resolvedOutPath);
+  return {
+    url: download.url?.() || "",
+    suggestedFilename: suggested,
+    path: path.resolve(resolvedOutPath),
+  };
+}
+
+async function awaitDownloadPayload(params: {
+  waiter: ReturnType<typeof createPageDownloadWaiter>;
+  state: ReturnType<typeof ensurePageState>;
+  armId: number;
+  outPath?: string;
+}) {
+  try {
+    const download = (await params.waiter.promise) as DownloadPayload;
+    if (params.state.armIdDownload !== params.armId) {
+      throw new Error("Download was superseded by another waiter");
+    }
+    return await saveDownloadPayload(download, params.outPath ?? "");
+  } catch (err) {
+    params.waiter.cancel();
+    throw err;
+  }
+}
+
 export async function armFileUploadViaPlaywright(opts: {
   cdpUrl: string;
   targetId?: string;
@@ -200,28 +236,7 @@ export async function waitForDownloadViaPlaywright(opts: {
   const armId = state.armIdDownload;
 
   const waiter = createPageDownloadWaiter(page, timeout);
-  try {
-    const download = (await waiter.promise) as {
-      url?: () => string;
-      suggestedFilename?: () => string;
-      saveAs?: (outPath: string) => Promise<void>;
-    };
-    if (state.armIdDownload !== armId) {
-      throw new Error("Download was superseded by another waiter");
-    }
-    const suggested = download.suggestedFilename?.() || "download.bin";
-    const outPath = opts.path?.trim() || buildTempDownloadPath(suggested);
-    await fs.mkdir(path.dirname(outPath), { recursive: true });
-    await download.saveAs?.(outPath);
-    return {
-      url: download.url?.() || "",
-      suggestedFilename: suggested,
-      path: path.resolve(outPath),
-    };
-  } catch (err) {
-    waiter.cancel();
-    throw err;
-  }
+  return await awaitDownloadPayload({ waiter, state, armId, outPath: opts.path });
 }
 
 export async function downloadViaPlaywright(opts: {
@@ -257,23 +272,7 @@ export async function downloadViaPlaywright(opts: {
     } catch (err) {
       throw toAIFriendlyError(err, ref);
     }
-
-    const download = (await waiter.promise) as {
-      url?: () => string;
-      suggestedFilename?: () => string;
-      saveAs?: (outPath: string) => Promise<void>;
-    };
-    if (state.armIdDownload !== armId) {
-      throw new Error("Download was superseded by another waiter");
-    }
-    const suggested = download.suggestedFilename?.() || "download.bin";
-    await fs.mkdir(path.dirname(outPath), { recursive: true });
-    await download.saveAs?.(outPath);
-    return {
-      url: download.url?.() || "",
-      suggestedFilename: suggested,
-      path: path.resolve(outPath),
-    };
+    return await awaitDownloadPayload({ waiter, state, armId, outPath });
   } catch (err) {
     waiter.cancel();
     throw err;