feat: implement Locator.prototype.wait (#10629)

docs/api/puppeteer.locator.md

@@ -37,3 +37,4 @@ export declare abstract class Locator<T> extends EventEmitter
 | [setVisibility(this, visibility)](./puppeteer.locator.setvisibility.md)                                |                     |                                                                                                                                                                                                                                          |
 | [setWaitForEnabled(this, value)](./puppeteer.locator.setwaitforenabled.md)                             |                     |                                                                                                                                                                                                                                          |
 | [setWaitForStableBoundingBox(this, value)](./puppeteer.locator.setwaitforstableboundingbox.md)         |                     |                                                                                                                                                                                                                                          |
+| [wait(options)](./puppeteer.locator.wait.md)                                                           |                     | <p>Waits for the locator to get the serialized value from the page.</p><p>Note this requires the value to be JSON-serializable.</p>                                                                                                      |

docs/api/puppeteer.locator.wait.md

@@ -0,0 +1,27 @@
+---
+sidebar_label: Locator.wait
+---
+
+# Locator.wait() method
+
+Waits for the locator to get the serialized value from the page.
+
+Note this requires the value to be JSON-serializable.
+
+#### Signature:
+
+```typescript
+class Locator {
+  wait(options?: Readonly<ActionOptions>): Promise<T>;
+}
+```
+
+## Parameters
+
+| Parameter | Type                                                          | Description  |
+| --------- | ------------------------------------------------------------- | ------------ |
+| options   | Readonly&lt;[ActionOptions](./puppeteer.actionoptions.md)&gt; | _(Optional)_ |
+
+**Returns:**
+
+Promise&lt;T&gt;

packages/puppeteer-core/src/api/locators/Locator.ts

@@ -635,6 +635,26 @@ export abstract class Locator<T> extends EventEmitter {
    */
   abstract _wait(options?: Readonly<ActionOptions>): Observable<HandleFor<T>>;
 
+  /**
+   * Waits for the locator to get the serialized value from the page.
+   *
+   * Note this requires the value to be JSON-serializable.
+   *
+   * @public
+   */
+  async wait(options?: Readonly<ActionOptions>): Promise<T> {
+    const handle = await firstValueFrom(
+      this._wait(options).pipe(
+        this.operators.retryAndRaceWithSignalAndTimer(options?.signal)
+      )
+    );
+    try {
+      return await handle.jsonValue();
+    } finally {
+      void handle.dispose().catch(debugError);
+    }
+  }
+
   /**
    * Creates an expectation that is evaluated against located values.
    *

packages/puppeteer-core/src/common/bidi/JSHandle.ts

@@ -115,12 +115,9 @@ export class JSHandle<T = unknown> extends BaseJSHandle<T> {
   }
 
   override async jsonValue(): Promise<T> {
-    const value = BidiSerializer.deserialize(this.#remoteValue);
+    return await this.evaluate(value => {
-
+      return value;
-    if (this.#remoteValue.type !== 'undefined' && value === undefined) {
+    });
-      throw new Error('Could not serialize referenced object');
-    }
-    return value;
   }
 
   override asElement(): ElementHandle<Node> | null {

test/TestExpectations.json

@@ -23,6 +23,12 @@
     "parameters": ["webDriverBiDi"],
     "expectations": ["PASS"]
   },
+  {
+    "testIdPattern": "[jshandle.spec] JSHandle JSHandle.jsonValue should not throw for circular objects",
+    "platforms": ["darwin", "linux", "win32"],
+    "parameters": ["cdp"],
+    "expectations": ["FAIL"]
+  },
   {
     "testIdPattern": "[elementhandle.spec] ElementHandle specs Custom queries *",
     "platforms": ["darwin", "linux", "win32"],

test/src/evaluation.spec.ts

@@ -345,24 +345,6 @@ describe('Evaluation specs', function () {
       });
       expect(result).toBe(undefined);
     });
-    it('should be able to throw a tricky error', async () => {
-      const {page} = await getTestState();
-
-      const windowHandle = await page.evaluateHandle(() => {
-        return window;
-      });
-      const errorText = await windowHandle.jsonValue().catch(error_ => {
-        return error_.message;
-      });
-      const error = await page
-        .evaluate(errorText => {
-          throw new Error(errorText);
-        }, errorText)
-        .catch(error_ => {
-          return error_;
-        });
-      expect(error.message).toContain(errorText);
-    });
     it('should accept a string', async () => {
       const {page} = await getTestState();
 

test/src/jshandle.spec.ts

@@ -163,7 +163,7 @@ describe('JSHandle', function () {
       expect(date).toBeInstanceOf(Date);
       expect(date.toISOString()).toEqual('2017-09-26T00:00:00.000Z');
     });
-    it('should throw for circular objects', async () => {
+    it('should not throw for circular objects', async () => {
       const {page} = await getTestState();
 
       const handle = await page.evaluateHandle(() => {
@@ -171,11 +171,7 @@ describe('JSHandle', function () {
         t.t = t;
         return t;
       });
-      let error!: Error;
+      await handle.jsonValue();
-      await handle.jsonValue().catch(error_ => {
-        return (error = error_);
-      });
-      expect(error.message).toContain('Could not serialize referenced object');
     });
   });
 

test/src/locator.spec.ts

@@ -569,4 +569,21 @@ describe('Locator', function () {
       }
     });
   });
+
+  describe('Locator.prototype.wait', () => {
+    it('should work', async () => {
+      const {page} = await getTestState();
+      page.setContent(`
+        <script>
+          setTimeout(() => {
+            const element = document.createElement("div");
+            element.innerText = "test2"
+            document.body.append(element);
+          }, 50);
+        </script>
+      `);
+      // This shouldn't throw.
+      await page.locator('div').wait();
+    });
+  });
 });