// We need to disable the following eslint check as it's only applicable // to testing-library/react not `react-test-renderer` used here /* eslint-disable testing-library/await-async-query */ /** * External dependencies */ import TestRenderer, { act } from 'react-test-renderer'; /** * Internal dependencies */ import { usePrevious } from '../use-previous'; describe( 'usePrevious', () => { const TestComponent = ( { testValue, validation } ) => { const previousValue = usePrevious( testValue, validation ); return
; }; let renderer; beforeEach( () => ( renderer = null ) ); it( 'should be undefined at first pass', () => { act( () => { renderer = TestRenderer.create( ); } ); const testValue = renderer.root.findByType( 'div' ).props.testValue; const testPreviousValue = renderer.root.findByType( 'div' ).props.previousValue; expect( testValue ).toBe( 1 ); expect( testPreviousValue ).toBe( undefined ); } ); it( 'test new and previous value', () => { let testValue; let testPreviousValue; act( () => { renderer = TestRenderer.create( ); } ); act( () => { renderer.update( ); } ); testValue = renderer.root.findByType( 'div' ).props.testValue; testPreviousValue = renderer.root.findByType( 'div' ).props.previousValue; expect( testValue ).toBe( 2 ); expect( testPreviousValue ).toBe( 1 ); act( () => { renderer.update( ); } ); testValue = renderer.root.findByType( 'div' ).props.testValue; testPreviousValue = renderer.root.findByType( 'div' ).props.previousValue; expect( testValue ).toBe( 3 ); expect( testPreviousValue ).toBe( 2 ); } ); it( 'should not update value if validation fails', () => { let testValue; let testPreviousValue; act( () => { renderer = TestRenderer.create( ); } ); act( () => { renderer.update( ); } ); testValue = renderer.root.findByType( 'div' ).props.testValue; testPreviousValue = renderer.root.findByType( 'div' ).props.previousValue; expect( testValue ).toBe( 'abc' ); expect( testPreviousValue ).toBe( 1 ); act( () => { renderer.update( ); } ); testValue = renderer.root.findByType( 'div' ).props.testValue; testPreviousValue = renderer.root.findByType( 'div' ).props.previousValue; expect( testValue ).toBe( 3 ); expect( testPreviousValue ).toBe( 1 ); } ); } );