Play with time

examples/logjam/src/log.js

@@ -6,11 +6,14 @@ import { sendToServer } from './send-to-server';
  * Log a message to the console in development mode or send it to the server in production mode.
  * @param  {string} message
  */
-export function log(message) {
-  if (import.meta.env.MODE !== 'production') {
+export function log(
+  message,
+  { productionCallback = () => {}, mode = import.meta.env.MODE } = {},
+) {
+  if (mode !== 'production') {
     console.log(message);
   } else {
-    sendToServer('info', message);
+    productionCallback('info', message);
   }
 }
 

examples/logjam/src/log.test.js

@@ -1,4 +1,33 @@
 import { expect, it, vi, beforeEach, afterEach, describe } from 'vitest';
 import { log } from './log';
 
-describe.todo('logger', () => {});
+describe('logger', () => {
+  describe('development', () => {
+    it('logs to the console in development mode', () => {
+      const logSpy = vi.fn();
+
+      log('Hello World');
+
+      expect(logSpy).toHaveBeenCalledWith('Hello World');
+    });
+  });
+
+  describe('production', () => {
+    beforeEach(() => {
+      vi.stubEnv('MODE', 'production');
+    });
+
+    afterEach(() => {
+      vi.restoreAllMocks();
+    });
+
+    it('should not call console.log in production', () => {
+      const logSpy = vi.spyOn(console, 'log');
+
+      log('Hello World', { mode: 'production', productionCallback: logSpy });
+
+      expect(logSpy).not.toHaveBeenCalled();
+      expect(sendToServer).toHaveBeenCalled();
+    });
+  });
+});

examples/logjam/src/send-to-server.js

@@ -4,5 +4,6 @@
  * @param {string} message
  */
 export const sendToServer = (level, message) => {
+  throw new Error('I should not run!');
   return `You must mock this function: sendToServer(${level}, ${message})`;
 };