Add tests for textContent().

packages/components/src/filters/advanced/test/utils.js

@@ -0,0 +1,83 @@
+/**
+ * Internal dependencies
+ */
+import { textContent } from '../utils';
+
+describe( 'textContent()', () => {
+	test( 'should be got text `Hello World`', () => {
+		const component = (
+			<div>
+				<h1>Hello</h1> World
+			</div>
+		);
+
+		expect( textContent( component ) ).toBe( 'Hello World' );
+	} );
+
+	test( 'render variable', () => {
+		const component = (
+			<div>
+				<h1>Hello</h1> { 'World' + '2' }
+			</div>
+		);
+
+		expect( textContent( component ) ).toBe( 'Hello World2' );
+	} );
+
+	test( 'render variable2', () => {
+		const component = (
+			<div>
+				<h1>Hello</h1> { 1 + 1 }
+			</div>
+		);
+
+		expect( textContent( component ) ).toBe( 'Hello 2' );
+	} );
+
+	test( 'should output empty string', () => {
+		const component = ( <div /> );
+
+		expect( textContent( component ) ).toBe( '' );
+	} );
+
+	test( 'array children', () => {
+		const component = (
+			<div>
+				<h1>Hello</h1> World
+				{
+					[ 'a', <h2 key="b">b</h2> ]
+				}
+			</div>
+		);
+
+		expect( textContent( component ) ).toBe( 'Hello Worldab' );
+	} );
+
+	test( 'array children with null', () => {
+		const component = (
+			<div>
+				<h1>Hello</h1> World
+				{
+					[ 'a', null ]
+				}
+			</div>
+		);
+
+		expect( textContent( component ) ).toBe( 'Hello Worlda' );
+	} );
+
+	test( 'array component', () => {
+		const component = ( [
+			<h1>a</h1>,
+			'b',
+			'c',
+			(
+				<div>
+					<h2>x</h2>y
+				</div>
+			),
+		] );
+
+		expect( textContent( component ) ).toBe( 'abcxy' );
+	} );
+} );