Allow task to recover after a failed graph start

PiperOrigin-RevId: 500324587

mediapipe/tasks/web/core/task_runner.ts

@@ -164,16 +164,19 @@ export abstract class TaskRunner {
 
   /** Throws the error from the error listener if an error was raised. */
   private handleErrors() {
-    const errorCount = this.processingErrors.length;
-    if (errorCount === 1) {
-      // Re-throw error to get a more meaningful stacktrace
-      throw new Error(this.processingErrors[0].message);
-    } else if (errorCount > 1) {
-      throw new Error(
-          'Encountered multiple errors: ' +
-          this.processingErrors.map(e => e.message).join(', '));
+    try {
+      const errorCount = this.processingErrors.length;
+      if (errorCount === 1) {
+        // Re-throw error to get a more meaningful stacktrace
+        throw new Error(this.processingErrors[0].message);
+      } else if (errorCount > 1) {
+        throw new Error(
+            'Encountered multiple errors: ' +
+            this.processingErrors.map(e => e.message).join(', '));
+      }
+    } finally {
+      this.processingErrors = [];
     }
-    this.processingErrors = [];
   }
 
   /** Configures the `externalFile` option */

mediapipe/tasks/web/core/task_runner_test.ts

@@ -139,6 +139,18 @@ describe('TaskRunner', () => {
     }).toThrowError(/Test error 1, Test error 2/);
   });
 
+  it('clears errors once thrown', () => {
+    taskRunner.enqueueError('Test error');
+
+    expect(() => {
+      taskRunner.setGraph(new Uint8Array(0), /* isBinary= */ true);
+    }).toThrowError(/Test error/);
+
+    expect(() => {
+      taskRunner.setGraph(new Uint8Array(0), /* isBinary= */ true);
+    }).not.toThrow();
+  });
+
   it('verifies that at least one model asset option is provided', () => {
     expect(() => {
       taskRunner.setOptions({});