Add unit tests for getParentLineIndex

packages/rich-text/src/test/get-parent-line-index.js

@@ -0,0 +1,43 @@
+/**
+ * External dependencies
+ */
+import deepFreeze from 'deep-freeze';
+
+/**
+ * Internal dependencies
+ */
+
+import { getParentLineIndex } from '../get-parent-line-index';
+import { LINE_SEPARATOR } from '../special-characters';
+
+describe( 'getParentLineIndex', () => {
+	const ul = { type: 'ul' };
+
+	it( 'should return undefined if there is only one line', () => {
+		expect( getParentLineIndex( deepFreeze( {
+			formats: [ , ],
+			text: '1',
+		} ), undefined ) ).toBe( undefined );
+	} );
+
+	it( 'should return undefined if the list is part of the first root list child', () => {
+		expect( getParentLineIndex( deepFreeze( {
+			formats: [ , ],
+			text: `1${ LINE_SEPARATOR }2`,
+		} ), 2 ) ).toBe( undefined );
+	} );
+
+	it( 'should return the line index of the parent list (1)', () => {
+		expect( getParentLineIndex( deepFreeze( {
+			formats: [ , , , [ ul ], , ],
+			text: `1${ LINE_SEPARATOR }2${ LINE_SEPARATOR }3`,
+		} ), 3 ) ).toBe( 1 );
+	} );
+
+	it( 'should return the line index of the parent list (2)', () => {
+		expect( getParentLineIndex( deepFreeze( {
+			formats: [ , [ ul ], , [ ul, ul ], , [ ul ], , ],
+			text: `1${ LINE_SEPARATOR }2${ LINE_SEPARATOR }3${ LINE_SEPARATOR }4`,
+		} ), 5 ) ).toBe( undefined );
+	} );
+} );