Mock time in tests

Author: dolfbarr

src/index.test.tsx

@@ -1,13 +1,16 @@
 import { useLog } from './index'
+import * as utils from './utils'
 import { act, renderHook } from '@testing-library/react'
 import { useEffect, useState } from 'react'
 
 describe('useLog', () => {
   const OLD_ENV = process.env
+  jest.spyOn(utils, 'getCurrentTime').mockReturnValue('09:38 PM')
   const consoleLog = jest.spyOn(console, 'log').mockImplementation(() => null)
   const consoleGroup = jest
     .spyOn(console, 'group')
     .mockImplementation(() => null)
+
   const consoleGroupCollapsed = jest
     .spyOn(console, 'groupCollapsed')
     .mockImplementation(() => null)
@@ -70,14 +73,14 @@ describe('useLog', () => {
      * Set Initial Values
      */
     expect(consoleGroup).toBeCalledWith(
-      `Mount in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      'Mount in %c<TestComponent /> %c@ 09:38 PM',
       'color: DodgerBlue',
       'color: SlateGray; font-weight: thin;',
     )
     expect(consoleLog).toBeCalledWith('      On mount: null')
 
     expect(consoleGroup).toBeCalledWith(
-      `Change in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      'Change in %c<TestComponent /> %c@ 09:38 PM',
       'color: DodgerBlue',
       'color: SlateGray; font-weight: thin;',
     )
@@ -90,7 +93,7 @@ describe('useLog', () => {
       'color: green; font-weight: bold;',
     )
     expect(consoleGroup).toBeCalledWith(
-      `Change in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      'Change in %c<TestComponent /> %c@ 09:38 PM',
       'color: DodgerBlue',
       'color: SlateGray; font-weight: thin;',
     )
@@ -113,7 +116,7 @@ describe('useLog', () => {
       logRerender()
     })
     expect(consoleGroup).toBeCalledWith(
-      `Change in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      'Change in %c<TestComponent /> %c@ 09:38 PM',
       'color: DodgerBlue',
       'color: SlateGray; font-weight: thin;',
     )
@@ -136,7 +139,7 @@ describe('useLog', () => {
       logRerender()
     })
     expect(consoleGroup).toBeCalledWith(
-      `Change in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      'Change in %c<TestComponent /> %c@ 09:38 PM',
       'color: DodgerBlue',
       'color: SlateGray; font-weight: thin;',
     )
@@ -158,7 +161,7 @@ describe('useLog', () => {
       logUnmount()
     })
     expect(consoleGroup).toBeCalledWith(
-      `Unmount in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      'Unmount in %c<TestComponent /> %c@ 09:38 PM',
       'color: DodgerBlue',
       'color: SlateGray; font-weight: thin;',
     )
@@ -261,7 +264,7 @@ describe('useLog', () => {
     expect(consoleGroupCollapsed).toHaveBeenCalled()
     // first call, first parameter for group name should exist
     expect(consoleGroupCollapsed.mock.calls[0][0]).toBe(
-      `Mount in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+      'Mount in %c<TestComponent /> %c@ 09:38 PM',
     )
   })
 

src/utils.test.ts

@@ -1,17 +1,18 @@
-import { getGroupLabel, getComponentName, print, getPrinter } from './utils'
+import * as utils from './utils'
 import { _PrintConfig, _PrintTypes, Printer } from './types'
 
+const { getGroupLabel, getComponentName, print, getPrinter } = utils
+
 describe('utils', () => {
+  jest.spyOn(utils, 'getCurrentTime').mockReturnValue('09:38 PM')
   describe('getGroupLabel', () => {
     it('renders', () => {
-      expect(getGroupLabel(_PrintTypes.Change)).toEqual(
-        `Change %c%c@ ${new Date().toLocaleTimeString()}`,
-      )
+      expect(getGroupLabel(_PrintTypes.Change)).toEqual('Change %c%c@ 09:38 PM')
     })
 
     it('renders with component name', () => {
       expect(getGroupLabel(_PrintTypes.Mount, 'TestComponent')).toEqual(
-        `Mount in %c<TestComponent /> %c@ ${new Date().toLocaleTimeString()}`,
+        'Mount in %c<TestComponent /> %c@ 09:38 PM',
       )
     })
   })
@@ -66,7 +67,7 @@ describe('utils', () => {
       print(printProps)
 
       expect(consoleGroup).toHaveBeenCalledWith(
-        `Change in %c<SomeComponentName /> %c@ ${new Date().toLocaleTimeString()}`,
+        'Change in %c<SomeComponentName /> %c@ 09:38 PM',
         undefined,
         undefined,
       )
@@ -79,7 +80,7 @@ describe('utils', () => {
       print({ ...printProps, prevValue: 'Some Previous value' })
 
       expect(consoleGroup).toHaveBeenCalledWith(
-        `Change in %c<SomeComponentName /> %c@ ${new Date().toLocaleTimeString()}`,
+        'Change in %c<SomeComponentName /> %c@ 09:38 PM',
         undefined,
         undefined,
       )
@@ -119,7 +120,7 @@ describe('utils', () => {
 
       expect(consoleGroup).not.toHaveBeenCalled()
       expect(consoleGroupCollapsed).toHaveBeenCalledWith(
-        `Change in %c<SomeComponentName /> %c@ ${new Date().toLocaleTimeString()}`,
+        'Change in %c<SomeComponentName /> %c@ 09:38 PM',
         undefined,
         undefined,
       )

src/utils.ts

@@ -1,6 +1,9 @@
+import * as utils from './utils'
 import { Printer, _PrintConfig, _PrintTypes, _SupportedConsole } from './types'
 
-export function getCurrentDate(): string {
+/* istanbul ignore next */
+export function getCurrentTime(): string {
+  // No need in testing Date module
   return new Date().toLocaleTimeString()
 }
 
@@ -12,9 +15,9 @@ export function getGroupLabel(
     ? `in %c<${String(componentName)} /> `
     : '%c'
   const typeWrapper = `${String(type)} `
-  const dateWrapper = `%c@ ${getCurrentDate()}`
+  const timeWrapper = `%c@ ${utils.getCurrentTime()}`
 
-  return `${typeWrapper}${componentNameWrapper}${dateWrapper}`
+  return `${typeWrapper}${componentNameWrapper}${timeWrapper}`
 }
 
 export function getComponentName(): string {