chore(scaffolder): add tests for makeLogStream

plugins/scaffolder-backend/src/scaffolder/jobs/logger.test.ts

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2020 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 { makeLogStream } from './logger';
+describe('Logger', () => {
+  const mockMeta = { test: 'blob' };
+
+  it('should return empty log lines by default', async () => {
+    const { log } = makeLogStream(mockMeta);
+
+    expect(log).toEqual([]);
+  });
+  it('should add lines to the log when using the logger that is returned', async () => {
+    const { logger, log } = makeLogStream(mockMeta);
+
+    logger.info('TEST LINE');
+    logger.warn('WARN LINE');
+
+    const [first, second] = log;
+    expect(log.length).toBe(2);
+
+    expect(first).toContain('info');
+    expect(first).toContain('TEST LINE');
+
+    expect(second).toContain('warn');
+    expect(second).toContain('WARN LINE');
+  });
+
+  it('should add lines from writing to the stream that is returned', async () => {
+    const { stream, log } = makeLogStream(mockMeta);
+    const textLine = 'SOMETHING';
+    stream.write(textLine);
+
+    expect(log).toContain(textLine);
+  });
+});