inspector: return Error objects on error

The inspector communicates errors via POJOs. This commit
wraps the error information in an actual Error object.

PR-URL: #26255
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: cjihrig

lib/inspector.js

@@ -3,6 +3,7 @@
 const {
   ERR_INSPECTOR_ALREADY_CONNECTED,
   ERR_INSPECTOR_CLOSED,
+  ERR_INSPECTOR_COMMAND,
   ERR_INSPECTOR_NOT_AVAILABLE,
   ERR_INSPECTOR_NOT_CONNECTED,
   ERR_INVALID_ARG_TYPE,
@@ -48,8 +49,14 @@ class Session extends EventEmitter {
       if (parsed.id) {
         const callback = this[messageCallbacksSymbol].get(parsed.id);
         this[messageCallbacksSymbol].delete(parsed.id);
-        if (callback)
-          callback(parsed.error || null, parsed.result || null);
+        if (callback) {
+          if (parsed.error) {
+            return callback(new ERR_INSPECTOR_COMMAND(parsed.error.code,
+                                                      parsed.error.message));
+          }
+
+          callback(null, parsed.result);
+        }
       } else {
         this.emit(parsed.method, parsed);
         this.emit('inspectorNotification', parsed);

test/sequential/test-inspector-runtime-evaluate-with-timeout.js

@@ -5,17 +5,22 @@ const common = require('../common');
 common.skipIfInspectorDisabled();
 
 (async function test() {
-  const { strictEqual } = require('assert');
+  const assert = require('assert');
   const { Session } = require('inspector');
   const { promisify } = require('util');
 
   const session = new Session();
   session.connect();
   session.post = promisify(session.post);
-  const result = await session.post('Runtime.evaluate', {
-    expression: 'for(;;);',
-    timeout: 0
-  }).catch((e) => e);
-  strictEqual(result.message, 'Execution was terminated');
+  await assert.rejects(
+    session.post('Runtime.evaluate', {
+      expression: 'for(;;);',
+      timeout: 0
+    }),
+    {
+      code: 'ERR_INSPECTOR_COMMAND',
+      message: 'Inspector error -32000: Execution was terminated'
+    }
+  );
   session.disconnect();
 })();