1# TestRunner 2 3> **Note** 4> 5> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version. 6 7## Modules to Import 8 9```js 10import TestRunner from '@ohos.application.testRunner' 11``` 12 13 14 15## TestRunner.onPrepare 16 17onPrepare(): void 18 19Prepares the unit test environment to run test cases. 20 21**System capability**: SystemCapability.Ability.AbilityRuntime.Core 22 23**Example** 24 25```js 26export default class UserTestRunner extends TestRunner { 27 onPrepare() { 28 console.log("Trigger onPrepare") 29 } 30}; 31``` 32 33 34 35## TestRunner.onRun 36 37onRun(): void 38 39Runs test cases. 40 41**System capability**: SystemCapability.Ability.AbilityRuntime.Core 42 43**Example** 44 45```js 46export default class UserTestRunner extends TestRunner { 47 onRun() { 48 console.log("Trigger onRun") 49 } 50}; 51``` 52