test: Add tests for QueryEngine and utils for query package.

packages/query/src/query-engine/tests/index.test.ts

@@ -0,0 +1,48 @@
+import { QueryEngine } from '@/query-engine';
+import { getConfig, getGraphqlUrl } from '@snapwp/core/config';
+import { ApolloClient, InMemoryCache } from '@apollo/client';
+
+jest.mock( '@snapwp/core/config', () => ( {
+	getConfig: jest.fn(),
+	getGraphqlUrl: jest.fn(),
+} ) );
+
+jest.mock( '@apollo/client', () => ( {
+	ApolloClient: jest.fn(),
+	InMemoryCache: jest.fn(),
+} ) );
+
+describe( 'QueryEngine', () => {
+	const validConfig = {
+		homeUrl: 'https://home.example.com',
+	};
+	const graphqlUrl = 'https://graphql.example.com';
+
+	beforeEach( () => {
+		jest.clearAllMocks();
+		( getConfig as jest.Mock ).mockReturnValue( validConfig );
+		( getGraphqlUrl as jest.Mock ).mockReturnValue( graphqlUrl );
+		( InMemoryCache as jest.Mock ).mockImplementation( () => ( {
+			writeQuery: jest.fn(),
+			readQuery: jest.fn(),
+		} ) );
+	} );
+
+	it( 'should initialize the QueryEngine correctly', () => {
+		QueryEngine.initialize();
+
+		expect( getGraphqlUrl ).toHaveBeenCalled();
+		expect( getConfig ).toHaveBeenCalled();
+		expect( ( QueryEngine as any ).graphqlEndpoint ).toBe( graphqlUrl );
+		expect( ( QueryEngine as any ).homeUrl ).toBe( validConfig.homeUrl );
+		expect( ( QueryEngine as any ).apolloClient ).toBeInstanceOf(
+			ApolloClient
+		);
+	} );
+
+	it( 'should be a singleton', () => {
+		const instance1 = QueryEngine.getInstance();
+		const instance2 = QueryEngine.getInstance();
+		expect( instance1 ).toBe( instance2 );
+	} );
+} );

packages/query/src/utils/parse-global-styles.ts

@@ -20,10 +20,18 @@ export default function parseQueryResult(
 ): GlobalHeadProps {
 	if ( queryData.errors?.length ) {
 		queryData.errors?.forEach( ( error ) => {
-			Logger.error( `Error fetching global styles: ${ error }` );
+			Logger.error(
+				`Error fetching global styles: ${ error?.message }`,
+				error
+			);
 		} );
 	}
 
+	// Check if globalStyles is null.
+	if ( queryData.data.globalStyles === null ) {
+		throw new GlobalStylesParseError( `Error fetching global styles.` );
+	}
+
 	if ( ! queryData.data && queryData.errors?.length ) {
 		throw new GlobalStylesParseError( `Error fetching global styles.` );
 	}

packages/query/src/utils/parse-template.ts

@@ -34,6 +34,13 @@ export default function parseQueryResult(
 		} );
 	}
 
+	// Check if data.templateByUri is null
+	if ( ! queryData.data.templateByUri ) {
+		throw new TemplateParseError(
+			`Error fetching template data for uri: ${ uri }`
+		);
+	}
+
 	if ( ! queryData.data && queryData.errors?.length ) {
 		throw new TemplateParseError(
 			`Error fetching template data for uri: ${ uri }`

packages/query/src/utils/tests/parse-global-styles.test.ts

@@ -0,0 +1,101 @@
+import { ApolloQueryResult } from '@apollo/client';
+import { Logger, GlobalStylesParseError } from '@snapwp/core';
+import parseQueryResult from '../parse-global-styles';
+import { GetGlobalStylesQuery } from '@graphqlTypes/graphql';
+
+jest.mock( '@snapwp/core', () => ( {
+	...jest.requireActual( '@snapwp/core' ),
+	Logger: {
+		error: jest.fn(),
+	},
+} ) );
+
+describe( 'parseQueryResult', () => {
+	beforeEach( () => {
+		jest.clearAllMocks();
+	} );
+
+	it( 'should parse valid query data correctly', () => {
+		const queryData: ApolloQueryResult< GetGlobalStylesQuery > = {
+			data: {
+				globalStyles: {
+					customCss: 'body { color: red; }',
+					stylesheet: 'styles.css',
+					renderedFontFaces: '@font-face { font-family: "MyFont"; }',
+				},
+			},
+			errors: [],
+			loading: false,
+			networkStatus: 7,
+		};
+
+		const result = parseQueryResult( queryData );
+
+		expect( result ).toEqual( {
+			customCss: 'body { color: red; }',
+			globalStylesheet: 'styles.css',
+			renderedFontFaces: '@font-face { font-family: "MyFont"; }',
+		} );
+	} );
+
+	it( 'should log errors and still parse data if both data and errors exist', () => {
+		const queryData: ApolloQueryResult< GetGlobalStylesQuery > = {
+			data: {
+				globalStyles: {
+					customCss: 'body { color: blue; }',
+					stylesheet: 'theme.css',
+					renderedFontFaces:
+						'@font-face { font-family: "OtherFont"; }',
+				},
+			},
+			errors: [ { message: 'Sample error message' } ],
+			loading: false,
+			networkStatus: 7,
+		};
+
+		const result = parseQueryResult( queryData );
+
+		expect( Logger.error ).toHaveBeenCalledWith(
+			'Error fetching global styles: Sample error message',
+			{ message: 'Sample error message' }
+		);
+		expect( result ).toEqual( {
+			customCss: 'body { color: blue; }',
+			globalStylesheet: 'theme.css',
+			renderedFontFaces: '@font-face { font-family: "OtherFont"; }',
+		} );
+	} );
+
+	it( 'should throw an error if `data.globalStyles` is null and errors exist', () => {
+		const queryData: ApolloQueryResult< GetGlobalStylesQuery > = {
+			data: { globalStyles: null },
+			errors: [ { message: 'Critical error occurred' } ],
+			loading: false,
+			networkStatus: 7,
+		};
+
+		expect( () => parseQueryResult( queryData ) ).toThrow(
+			GlobalStylesParseError
+		);
+		expect( Logger.error ).toHaveBeenCalledWith(
+			'Error fetching global styles: Critical error occurred',
+			{ message: 'Critical error occurred' }
+		);
+	} );
+
+	it( 'should throw an error if `data.globalStyles` is null and no errors exist', () => {
+		const queryData: ApolloQueryResult< GetGlobalStylesQuery > = {
+			data: { globalStyles: null },
+			// @ts-ignore
+			// data: null,
+			errors: [],
+			loading: false,
+			networkStatus: 7,
+		};
+
+		expect( () => parseQueryResult( queryData ) ).toThrow(
+			GlobalStylesParseError
+		);
+		expect( Logger.error ).not.toHaveBeenCalled();
+	} );
+} );

packages/query/src/utils/tests/parse-template.test.ts

@@ -0,0 +1,112 @@
+import { ApolloQueryResult } from '@apollo/client';
+import {
+	BlockData,
+	Logger,
+	TemplateParseError,
+	TemplateData,
+} from '@snapwp/core';
+import parseQueryResult from '@/utils/parse-template';
+import { GetCurrentTemplateQuery } from '@graphqlTypes/graphql';
+
+jest.mock( '@snapwp/core', () => ( {
+	...jest.requireActual( '@snapwp/core' ),
+	Logger: {
+		error: jest.fn(),
+	},
+} ) );
+
+describe( 'parseQueryResult', () => {
+	const wordpressUrl = 'https://test.com';
+	const uri = '/sample-template';
+
+	beforeEach( () => {
+		jest.clearAllMocks();
+	} );
+
+	it( 'should parse valid query data correctly', () => {
+		const queryData: ApolloQueryResult< GetCurrentTemplateQuery > = {
+			data: {
+				templateByUri: {
+					bodyClasses: [ 'class1', 'class2' ],
+					enqueuedScripts: {
+						nodes: [
+							{
+								id: '122',
+								src: '/script.js',
+								handle: 'test-script',
+							},
+							{
+								id: '123',
+								src: 'https://cdn.com/script.js',
+								handle: 'cdn-script',
+							},
+						],
+					},
+					enqueuedStylesheets: {
+						nodes: [
+							{
+								src: '/style.css',
+								handle: 'test-style',
+								before: [ 'before-content' ],
+								after: [ 'after-content' ],
+							},
+						],
+					},
+					editorBlocks: [
+						{
+							type: 'core/paragraph',
+							renderedHtml: '<p>Text</p>',
+						},
+					],
+				},
+			},
+			errors: [],
+			loading: false,
+			networkStatus: 7,
+		};
+
+		const result = parseQueryResult( queryData, wordpressUrl, uri );
+
+		expect( result ).toEqual< TemplateData >( {
+			stylesheets: [
+				{
+					src: 'https://test.com/style.css',
+					handle: 'test-style',
+					before: 'before-content',
+					after: 'after-content',
+				},
+			],
+			editorBlocks: [
+				{
+					type: 'core/paragraph',
+					renderedHtml: '<p>Text</p>',
+				},
+			],
+			scriptModules: undefined,
+			scripts: [
+				{ src: 'https://test.com/script.js', handle: 'test-script' },
+				{ src: 'https://cdn.com/script.js', handle: 'cdn-script' },
+			],
+			bodyClasses: [ 'class1', 'class2' ],
+		} );
+	} );
+
+	it( 'should throw an error if `data` is null and errors exist', () => {
+		const queryData: ApolloQueryResult< GetCurrentTemplateQuery > = {
+			data: { templateByUri: null },
+			errors: [ { message: 'Critical error occurred' } ],
+			loading: false,
+			networkStatus: 7,
+		};
+
+		expect( () =>
+			parseQueryResult( queryData, wordpressUrl, uri )
+		).toThrow( TemplateParseError );
+
+		expect( Logger.error ).toHaveBeenCalledWith(
+			'Error fetching template data: Critical error occurred.',
+			'(Please refer to our FAQs for steps to debug and fix)',
+			{ message: 'Critical error occurred' }
+		);
+	} );
+} );