refactor: clean and test worklet error handling

js/AudioWorklet.js

@@ -46,14 +46,14 @@ const resolveModule = async (moduleUrl) => {
         const res = await fetch(moduleUrl);
         code = await res.text();
       } catch (err) {
-        throw new Error(`Failed to execute 'addModule' on 'AudioWorklet': ${err.message}`);
+        throw new DOMException(`Failed to execute 'addModule' on 'AudioWorklet': ${err.message}`, 'AbortError');
       }
   } else if (moduleUrl.startsWith('blob:')) {
     try {
       const blob = resolveObjectURL(moduleUrl);
       code = await blob.text();
     } catch (err) {
-      throw new Error(`Failed to execute 'addModule' on 'AudioWorklet': ${err.message}`);
+      throw new DOMException(`Failed to execute 'addModule' on 'AudioWorklet': ${err.message}`, 'AbortError');
     }
   } else {
     // get caller site from error stack trace
@@ -75,7 +75,7 @@ const resolveModule = async (moduleUrl) => {
         const res = await fetch(url);
         code = await res.text();
       } catch (err) {
-        throw new Error(`Failed to execute 'addModule' on 'AudioWorklet': ${err.message}`);
+        throw new DOMException(`Failed to execute 'addModule' on 'AudioWorklet': ${err.message}`, 'AbortError');
       }
     } else {
       const dirname = callerSite.substr(0, callerSite.lastIndexOf(path.sep));
@@ -85,7 +85,7 @@ const resolveModule = async (moduleUrl) => {
       if (existsSync(pathname)) {
         absPathname = pathname;
       } else {
-        throw new Error(`Failed to execute 'addModule' on 'AudioWorklet': Cannot resolve module ${moduleUrl}`);
+        throw new DOMException(`Failed to execute 'addModule' on 'AudioWorklet': Cannot resolve module ${moduleUrl}`, 'AbortError');
       }
     }
   }
@@ -128,10 +128,9 @@ class AudioWorklet {
           break;
         }
         case 'node-web-audio-api:worklet:add-module-failed': {
-          const { promiseId, ctor, name, message } = event;
+          const { promiseId, err } = event;
           const { reject } = this.#idPromiseMap.get(promiseId);
           this.#idPromiseMap.delete(promiseId);
-          const err = new globalThis[ctor](message, name);
           reject(err);
           break;
         }

js/AudioWorkletGlobalScope.js

@@ -334,9 +334,7 @@ parentPort.on('message', async event => {
         parentPort.postMessage({
           cmd: 'node-web-audio-api:worklet:add-module-failed',
           promiseId,
-          ctor: err.constructor.name,
-          name: err.name,
-          message: err.message,
+          err,
         });
       }
       break;
@@ -358,7 +356,6 @@ parentPort.on('message', async event => {
       try {
         instance = new ctor(options);
       } catch (err) {
-        // @todo - this is not clean at all...
         port.postMessage({ cmd: 'node-web-audio-api:worklet:ctor-error', err });
         return;
       }

js/AudioWorkletNode.js

@@ -222,7 +222,8 @@ module.exports = (jsExport, nativeBinding) => {
       );
 
       this.#port.on('message', msg => {
-        // ErrorEvent named processorerror
+        // Handle 'processorerror' ErrorEvent
+        // cf. https://webaudio.github.io/web-audio-api/#dom-audioworkletnode-onprocessorerror
         switch (msg.cmd) {
           case 'node-web-audio-api:worklet:ctor-error': {
             const message = `Failed to construct '${parsedName}' AudioWorkletProcessor: ${msg.err.message}`;

tests/AudioWorklet.spec.mjs

@@ -1,6 +1,7 @@
 import { Blob } from 'node:buffer';
 import { assert } from 'chai';
 import { AudioContext, OscillatorNode, AudioWorkletNode } from '../index.mjs';
+import { delay } from '@ircam/sc-utils';
 
 const scriptTexts = `
 class FirstProcessor extends AudioWorkletProcessor {
@@ -62,6 +63,62 @@ describe('AudioWorklet', () => {
 
     it.skip(`should support loading from cwd relative path`, async () => {});
     it.skip(`should support loading from caller relative path`, async () => {});
+    it.skip(`should support loading from node_modules`, async () => {});
     it.skip(`should support loading from url`, async () => {});
+
+    it(`should throw clean error`, async () => {
+      // blob worklets do not support import
+      const blob = new Blob(['import stuff from "./abc"'], { type: 'application/javascript' });
+      const objectUrl = URL.createObjectURL(blob);
+
+      const audioContext = new AudioContext();
+      let errored = false;
+
+      try {
+        await audioContext.audioWorklet.addModule(objectUrl);
+      } catch (err) {
+        console.log(err);
+        errored = true;
+      }
+
+      await audioContext.close();
+      assert.isTrue(errored);
+    });
+
+    it(`should throw clean error`, async () => {
+      const audioContext = new AudioContext();
+      let errored = false;
+
+      try {
+        await audioContext.audioWorklet.addModule('./worklets/invalid.worklet.mjs');
+      } catch (err) {
+        console.log(err);
+        errored = true;
+      }
+
+      await audioContext.close();
+      assert.isTrue(errored);
+    });
   });
 });
+
+describe('AudioWorkletNode', () => {
+  describe('# processor', () => {
+    it('should throw a clean error when processor constructor is invalid', async () => {
+      let errored = false;
+
+      const audioContext = new AudioContext();
+      await audioContext.audioWorklet.addModule('./worklets/invalid-ctor.worklet.mjs');
+
+      const invalid = new AudioWorkletNode(audioContext, 'invalid-ctor');
+      invalid.addEventListener('processorerror', (e) => {
+        console.log(e.error);
+        errored = true;
+      });
+
+      await delay(100);
+      await audioContext.close();
+      assert.isTrue(errored);
+    });
+  });
+})

tests/worklets/invalid-ctor.worklet.mjs

@@ -0,0 +1,13 @@
+class InvalidCtor extends AudioWorkletProcessor {
+  constructor() {
+    super();
+
+    this.stuff = invalid;
+  }
+
+  process(inputs, outputs, parameters) {
+    return true;
+  }
+}
+
+registerProcessor('invalid-ctor', InvalidCtor);

tests/worklets/invalid.worklet.js

@@ -0,0 +1 @@
+const a = invalid;

tests/worklets/invalid.worklet.mjs

@@ -0,0 +1 @@
+const a = invalid;