Replace Jest with Node's built in test runner (part 1)

dotcom-rendering/eslint.config.mjs

@@ -65,7 +65,11 @@ const rulesToEnforce = {
 
 export default defineConfig([
 	...guardian.configs.recommended,
-	...guardian.configs.jest,
+	...guardian.configs.jest.map((config) => ({
+		...config,
+		// Don't apply Jest globals to Node test files
+		ignores: [...(config.ignores ?? []), '**/*.node.test.ts'],
+	})),
 	...guardian.configs.react,
 	...guardian.configs.storybook,
 	// eslint-plugin-prettier/recommended should be the last item in the configuration array so that eslint-config-prettier has the opportunity to override other configs

dotcom-rendering/jest.config.js

@@ -23,6 +23,7 @@ module.exports = {
 		'^.+\\.(mjs|js|ts|tsx)$': ['@swc/jest', swcConfig],
 	},
 	testMatch: ['**/*.test.+(ts|tsx|js)'],
+	testPathIgnorePatterns: ['\\.node\\.test\\.'],
 	setupFilesAfterEnv: ['<rootDir>/scripts/jest/setup.ts'],
 	moduleNameMapper: {
 		'^svgs/(.*)$': '<rootDir>/__mocks__/svgMock.tsx',

dotcom-rendering/package.json

@@ -10,6 +10,7 @@
 		"lint:stats": "pnpm lint --format node_modules/eslint-stats/byError.js",
 		"tsc": "tsc",
 		"test": "IMAGE_DIGEST=sha256:12345 jest --maxWorkers=50%",
+		"test:node": "IMAGE_DIGEST=sha256:12345 node --import=tsx --test \"src/**/*.node.test.ts\"",
 		"test:watch": "IMAGE_DIGEST=sha256:12345 jest --watch --maxWorkers=25%",
 		"test:ci": "IMAGE_DIGEST=sha256:12345 jest --runInBand",
 		"playwright:open": "playwright test --ui",

dotcom-rendering/src/components/ElectionTrackers/electionComponent.test.ts → dotcom-rendering/src/components/ElectionTrackers/electionComponent.node.test.ts

@@ -1,3 +1,4 @@
+import { it } from 'node:test';
 import { parse } from 'valibot';
 import { euParliament } from '../../../fixtures/manual/electionTrackers/euParliament';
 import { ukGeneralExitPoll } from '../../../fixtures/manual/electionTrackers/ukGeneralExitPoll';
@@ -7,26 +8,26 @@ import { usCongressEmpty } from '../../../fixtures/manual/electionTrackers/usCon
 import { usPresidential } from '../../../fixtures/manual/electionTrackers/usPresidential';
 import { ElectionComponents } from './electionComponent';
 
-it('validates US Congress data', () => {
+void it('validates US Congress data', () => {
 	parse(ElectionComponents, usCongressEmpty);
 });
 
-it('validates UK General data', () => {
+void it('validates UK General data', () => {
 	parse(ElectionComponents, ukGeneralFinal);
 });
 
-it('validates UK General Exit Poll data', () => {
+void it('validates UK General Exit Poll data', () => {
 	parse(ElectionComponents, ukGeneralExitPoll);
 });
 
-it('validates UK Local data', () => {
+void it('validates UK Local data', () => {
 	parse(ElectionComponents, ukLocal);
 });
 
-it('validates US Presidential data', () => {
+void it('validates US Presidential data', () => {
 	parse(ElectionComponents, usPresidential);
 });
 
-it('validates EU Parliament data', () => {
+void it('validates EU Parliament data', () => {
 	parse(ElectionComponents, euParliament);
 });

dotcom-rendering/src/cricketMatch.test.ts → dotcom-rendering/src/cricketMatch.node.test.ts

@@ -1,14 +1,16 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
 import { liveMatch, resultMatch } from '../fixtures/manual/cricketMatch';
 import { parseCricketMatch } from './cricketMatch';
 
-describe('parseCricketMatchV2', () => {
-	it('parses a winner result cricket match correctly', () => {
+void describe('parseCricketMatchV2', () => {
+	void it('parses a winner result cricket match correctly', () => {
 		const result = parseCricketMatch(resultMatch).getOrThrow(
 			'Expected parsing cricket match to succeed',
 		);
 
-		expect(result.kind).toEqual('Result');
-		expect(result.result).toEqual({
+		assert.equal(result.kind, 'Result');
+		assert.deepEqual(result.result, {
 			type: 'home-win',
 			description: 'England win by 115 runs',
 			winner: {
@@ -17,32 +19,35 @@ describe('parseCricketMatchV2', () => {
 				margin: 115,
 			},
 		});
-		expect(result.matchDate).toEqual(new Date('2026-06-17T10:00:00.000Z'));
+		assert.deepEqual(
+			result.matchDate,
+			new Date('2026-06-17T10:00:00.000Z'),
+		);
 	});
 
-	it('parses a cricket match in pre-match status', () => {
+	void it('parses a cricket match in pre-match status', () => {
 		const result = parseCricketMatch({
 			...liveMatch,
 			result: 'pre-match',
 			fullResult: undefined,
 		}).getOrThrow('Expected parsing cricket match to succeed');
 
-		expect(result.kind).toEqual('Fixture');
-		expect(result.result).toEqual(undefined);
+		assert.equal(result.kind, 'Fixture');
+		assert.equal(result.result, undefined);
 	});
 
-	it('parses a cricket match in in-play status', () => {
+	void it('parses a cricket match in in-play status', () => {
 		const result = parseCricketMatch({
 			...liveMatch,
 			result: 'in-play',
 			fullResult: undefined,
 		}).getOrThrow('Expected parsing cricket match to succeed');
 
-		expect(result.kind).toEqual('Live');
-		expect(result.result).toEqual(undefined);
+		assert.equal(result.kind, 'Live');
+		assert.equal(result.result, undefined);
 	});
 
-	it('parses an abandoned cricket match correctly', () => {
+	void it('parses an abandoned cricket match correctly', () => {
 		const result = parseCricketMatch({
 			...liveMatch,
 			fullResult: {
@@ -52,14 +57,13 @@ describe('parseCricketMatchV2', () => {
 			},
 		}).getOrThrow('Expected parsing cricket match to succeed');
 
-		expect(result.result).toEqual({
+		assert.deepEqual(result.result, {
 			type: 'abandoned',
 			description: 'Match abandoned due to rain',
-			winner: undefined,
 		});
 	});
 
-	it('parses a cricket match with no winner', () => {
+	void it('parses a cricket match with no winner', () => {
 		const result = parseCricketMatch({
 			...liveMatch,
 			fullResult: {
@@ -69,10 +73,9 @@ describe('parseCricketMatchV2', () => {
 			},
 		}).getOrThrow('Expected parsing cricket match to succeed');
 
-		expect(result.result).toEqual({
+		assert.deepEqual(result.result, {
 			type: 'no-result',
 			description: 'No result',
-			winner: undefined,
 		});
 	});
 });

dotcom-rendering/src/footballMatches.test.ts → dotcom-rendering/src/footballMatches.node.test.ts

@@ -1,3 +1,5 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
 import { footballData } from '../fixtures/generated/football-live';
 import {
 	emptyMatches,
@@ -25,25 +27,25 @@ const withMatches = (
 		})),
 	}));
 
-describe('footballMatches', () => {
-	it('should parse match fixtures correctly', () => {
+void describe('footballMatches', () => {
+	void it('should parse match fixtures correctly', () => {
 		const result = parse(footballData.matchesList).getOrThrow(
 			'Expected football match parsing to succeed',
 		);
 
-		expect(result.length).toBe(1);
+		assert.equal(result.length, 1);
 
 		const day = result[0];
-		expect(day?.dateISOString).toBe('2025-04-28T00:00:00.000Z');
-		expect(day?.competitions.length).toBe(2);
+		assert.equal(day?.dateISOString, '2025-04-28T00:00:00.000Z');
+		assert.equal(day?.competitions.length, 2);
 
 		const competition = day?.competitions[0];
-		expect(competition?.name).toBe('Serie A');
-		expect(competition?.matches[0]?.kind).toBe('Fixture');
-		expect(competition?.tag).toBe('football/serieafootball');
+		assert.equal(competition?.name, 'Serie A');
+		assert.equal(competition?.matches[0]?.kind, 'Fixture');
+		assert.equal(competition?.tag, 'football/serieafootball');
 	});
 
-	it('should return an error when football days have invalid dates', () => {
+	void it('should return an error when football days have invalid dates', () => {
 		const invalidDate: FEMatchByDateAndCompetition[] = emptyMatches.map(
 			(day) => ({
 				...day,
@@ -55,10 +57,10 @@ describe('footballMatches', () => {
 			'Expected football match parsing to fail',
 		);
 
-		expect(result.kind).toBe('FootballDayInvalidDate');
+		assert.equal(result.kind, 'FootballDayInvalidDate');
 	});
 
-	it('should return an error when football matches have an invalid date', () => {
+	void it('should return an error when football matches have an invalid date', () => {
 		const invalidMatchResult: FEMatchByDateAndCompetition[] = withMatches([
 			matchFixture,
 			{ ...matchResult, date: '' },
@@ -85,24 +87,24 @@ describe('footballMatches', () => {
 			'Expected football match parsing to fail',
 		);
 
-		expect(resultOne.kind).toBe('FootballMatchInvalidDate');
-		expect(resultTwo.kind).toBe('FootballMatchInvalidDate');
+		assert.equal(resultOne.kind, 'FootballMatchInvalidDate');
+		assert.equal(resultTwo.kind, 'FootballMatchInvalidDate');
 
 		if (resultThree.kind !== 'InvalidMatchDay') {
 			throw new Error('Expected an invalid match day error');
 		}
 
-		expect(resultThree.errors[0]!.kind).toBe('FootballMatchInvalidDate');
+		assert.equal(resultThree.errors[0]!.kind, 'FootballMatchInvalidDate');
 	});
 
-	it('should return an error when it receives a live match', () => {
+	void it('should return an error when it receives a live match', () => {
 		const result = parse(withMatches([liveMatch])).getErrorOrThrow(
 			'Expected football match parsing to fail',
 		);
 
-		expect(result.kind).toBe('UnexpectedLiveMatch');
+		assert.equal(result.kind, 'UnexpectedLiveMatch');
 	});
-	it('should return a clean team name', () => {
+	void it('should return a clean team name', () => {
 		const matchesListWithTeamName = (teamName: string): FEResult => {
 			return {
 				...matchResult,
@@ -136,10 +138,10 @@ describe('footballMatches', () => {
 				throw new Error('Expected Result');
 			}
 
-			expect(match.homeTeam.name).toBe(cleanName);
+			assert.equal(match.homeTeam.name, cleanName);
 		}
 	});
-	it('should replace known live match status with our status', () => {
+	void it('should replace known live match status with our status', () => {
 		const matchDay = parse(
 			withMatches([matchDayLiveSecondHalf]),
 		).getOrThrow('Expected football live match parsing to succeed');
@@ -149,9 +151,9 @@ describe('footballMatches', () => {
 			throw new Error('Expected live match');
 		}
 
-		expect(match.status).toBe('2nd');
+		assert.equal(match.status, '2nd');
 	});
-	it('should replace unknown live match status with first two characters', () => {
+	void it('should replace unknown live match status with first two characters', () => {
 		const matchDayLiveUnknownStatus = {
 			...matchDayLiveSecondHalf,
 			matchStatus: 'Something odd',
@@ -166,6 +168,6 @@ describe('footballMatches', () => {
 			throw new Error('Expected live match');
 		}
 
-		expect(match.status).toBe('So');
+		assert.equal(match.status, 'So');
 	});
 });

dotcom-rendering/src/lib/acquisitions.test.ts → dotcom-rendering/src/lib/acquisitions.node.test.ts

@@ -1,7 +1,9 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
 import { addTrackingCodesToUrl } from './acquisitions';
 
-describe('acquisitions', () => {
-	it('should addTrackingCodesToUrl', () => {
+void describe('acquisitions', () => {
+	void it('should addTrackingCodesToUrl', () => {
 		const result = addTrackingCodesToUrl({
 			base: `https://support.theguardian.com/contribute`,
 			componentType: 'ACQUISITIONS_HEADER',
@@ -15,7 +17,8 @@ describe('acquisitions', () => {
 			referrerUrl: 'https://theguardian.com/uk',
 		});
 
-		expect(result).toEqual(
+		assert.equal(
+			result,
 			'https://support.theguardian.com/contribute?REFPVID=abcdefg&INTCMP=header_support&acquisitionData=%7B%22source%22%3A%22GUARDIAN_WEB%22%2C%22componentId%22%3A%22header_support%22%2C%22componentType%22%3A%22ACQUISITIONS_HEADER%22%2C%22campaignCode%22%3A%22header_support%22%2C%22abTest%22%3A%7B%22name%22%3A%22testName%22%2C%22variant%22%3A%22variantName%22%7D%2C%22referrerPageviewId%22%3A%22abcdefg%22%2C%22referrerUrl%22%3A%22https%3A%2F%2Ftheguardian.com%2Fuk%22%7D',
 		);
 	});

dotcom-rendering/src/lib/ad-targeting.test.ts → dotcom-rendering/src/lib/ad-targeting.node.test.ts

@@ -1,3 +1,5 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
 import { buildAdTargeting } from './ad-targeting';
 
 const sharedAdTargeting = {
@@ -12,7 +14,7 @@ const sharedAdTargeting = {
 	url: '/money/2017/mar/10/ministers-to-criminalise-use-of-ticket-tout-harvesting-software',
 };
 
-describe('buildAdTargeting', () => {
+void describe('buildAdTargeting', () => {
 	const expectedAdTargeting = {
 		adUnit: '/59666047/theguardian.com/money/article/ng',
 		customParams: {
@@ -38,8 +40,8 @@ describe('buildAdTargeting', () => {
 		},
 	};
 
-	it('builds adTargeting correctly', () => {
-		expect(
+	void it('builds adTargeting correctly', () => {
+		assert.deepEqual(
 			buildAdTargeting({
 				isAdFreeUser: false,
 				isSensitive: false,
@@ -48,6 +50,7 @@ describe('buildAdTargeting', () => {
 				sharedAdTargeting,
 				adUnit: '/59666047/theguardian.com/money/article/ng',
 			}),
-		).toEqual(expectedAdTargeting);
+			expectedAdTargeting,
+		);
 	});
 });