fix(cli): fix TypeError when formatting error messages

error.errors can be undefined which will lead to a TypeError, swallowing the actual error message in the process

Signed-off-by: Max Falk <gmdfalk@gmail.com>

packages/cli/src/lib/builder/packager.test.ts

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2021 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { formatErrorMessage } from './packager';
+
+describe('formatErrorMessage with esbuild plugin error', () => {
+  it('given error with missing errors array then error message should be shown', () => {
+    const msg = formatErrorMessage({
+      code: 'PLUGIN_ERROR',
+      plugin: 'esbuild',
+      message: 'test',
+    });
+    expect(msg).toBe('test\n\n');
+  });
+});

packages/cli/src/lib/builder/packager.ts

@@ -22,7 +22,7 @@ import { paths } from '../paths';
 import { makeConfigs } from './config';
 import { BuildOptions } from './types';
 
-function formatErrorMessage(error: any) {
+export function formatErrorMessage(error: any) {
   let msg = '';
 
   if (error.code === 'PLUGIN_ERROR') {