test(loggerImpl): write tests for loggerImpl

test/unit/libraries/logger/loggerImplSpec.ts

@@ -0,0 +1,29 @@
+import * as sinon from 'sinon';
+import { assert } from 'chai';
+import LoggerImpl from '../../../../src/libraries/logger/loggerImpl';
+
+const fakeConsole = {
+  log: sinon.stub()
+};
+
+describe('LoggerImpl', () => {
+  const appName = 'InversifyJsExample';
+  const sandbox = sinon.createSandbox();
+
+  let subjectUnderTest: LoggerImpl;
+
+  beforeEach(() => {
+    subjectUnderTest = new LoggerImpl({ appName }, fakeConsole);
+  });
+
+  afterEach(() => sandbox.restore());
+
+  it('should call "console.log" when log is called', () => {
+    const message = 'test';
+
+    subjectUnderTest.log(message);
+
+    const consoleLogCalled = fakeConsole.log.calledWith(appName + ' says: ' + message);
+    assert(consoleLogCalled, 'console.log should have been called');
+  });
+});