DRY up tests

Author: sindresorhus

test/assertion-arguments.js

@@ -1,12 +1,7 @@
-import test from 'ava';
-import AvaRuleTester from 'eslint-ava-rule-tester';
+import RuleTester from './helpers/rule-tester.js';
 import rule from '../rules/assertion-arguments.js';
 
-const ruleTester = new AvaRuleTester(test, {
-	languageOptions: {
-		ecmaVersion: 'latest',
-	},
-});
+const ruleTester = new RuleTester();
 
 const missingError = {messageId: 'missing-message'};
 const foundError = {messageId: 'found-message'};
@@ -20,16 +15,12 @@ const outOfOrderError = (line, column, endLine, endColumn) => ({
 const messageIsNotStringError = {messageId: 'not-string-message'};
 const regexFirstError = {messageId: 'regex-first-argument'};
 
-const header = 'const test = require(\'ava\');';
-
-function testCode(content, useHeader) {
-	const testFunction = `
+function testCode(content) {
+	return `
 		test(t => {
 			${content}
 		});
 	`;
-	const code = (useHeader === false ? '' : header) + testFunction;
-	return code;
 }
 
 function offsetError(error, line, column) {
@@ -55,24 +46,28 @@ function offsetError(error, line, column) {
 }
 
 function testCase(message, content, errors = [], {
-	useHeader, output = null,
+	noHeader, output = null,
 } = {}) {
 	if (!Array.isArray(errors)) {
 		errors = [errors];
 	}
 
-	const offset = useHeader === false ? [1, 3] : [2, 3];
+	const offset = noHeader ? [2, 3] : [3, 3];
 
 	errors = errors.map(error => offsetError(error, ...offset));
 
 	const result = {
 		options: message ? [{message}] : [],
-		code: testCode(content, useHeader),
+		code: testCode(content),
 	};
 
+	if (noHeader) {
+		result.noHeader = true;
+	}
+
 	if (errors.length > 0) {
 		result.errors = errors;
-		result.output = output === null ? null : testCode(output, useHeader);
+		result.output = output === null ? null : testCode(output);
 	}
 
 	return result;
@@ -157,9 +152,6 @@ const dynamics = [
 ];
 
 ruleTester.run('assertion-arguments', rule, {
-	assertionOptions: {
-		requireMessage: true,
-	},
 	valid: [
 		testCase(false, 't.plan(1);'),
 		testCase(false, 't.plan(0);'),
@@ -194,7 +186,7 @@ ruleTester.run('assertion-arguments', rule, {
 		testCase(false, 't.timeout(100, \'message\');'),
 		testCase(false, 'foo.t.plan();'),
 		// Shouldn't be triggered since it's not a test file
-		testCase(false, 't.true(true);', [], {useHeader: false}),
+		testCase(false, 't.true(true);', [], {noHeader: true}),
 
 		testCase(false, 't.assert(true);'),
 		testCase(false, 't.deepEqual({}, {});'),
@@ -221,7 +213,7 @@ ruleTester.run('assertion-arguments', rule, {
 		testCase(false, 't.truthy(\'unicorn\');'),
 		testCase(false, 't.snapshot(value);'),
 		// Shouldn't be triggered since it's not a test file
-		testCase(false, 't.true(true, \'message\');', [], {useHeader: false}),
+		testCase(false, 't.true(true, \'message\');', [], {noHeader: true}),
 
 		testCase(false, 't.context.a(1, 2, 3, 4);'),
 		testCase(false, 't.context.is(1, 2, 3, 4);'),
@@ -257,7 +249,7 @@ ruleTester.run('assertion-arguments', rule, {
 		testCase('always', 't.try(\'title\', tt => tt.pass(\'ok\'), 1, 2);'),
 
 		// Shouldn't be triggered since it's not a test file
-		testCase('always', 't.true(true);', [], {useHeader: false}),
+		testCase('always', 't.true(true);', [], {noHeader: true}),
 
 		testCase('always', 't.context.a(1, 2, 3, 4);'),
 		testCase('always', 't.context.is(1, 2, 3, 4);'),
@@ -295,7 +287,7 @@ ruleTester.run('assertion-arguments', rule, {
 		testCase('never', 't.try(\'title\', tt => tt.pass(), 1, 2);'),
 
 		// Shouldn't be triggered since it's not a test file
-		testCase('never', 't.true(true, \'message\');', [], {useHeader: false}),
+		testCase('never', 't.true(true, \'message\');', [], {noHeader: true}),
 
 		testCase('never', 't.context.a(1, 2, 3, 4);'),
 		testCase('never', 't.context.is(1, 2, 3, 4);'),

test/create-ava-rule.js

@@ -1,5 +1,4 @@
-import test from 'ava';
-import AvaRuleTester from 'eslint-ava-rule-tester';
+import RuleTester from './helpers/rule-tester.js';
 import tsParser from '@typescript-eslint/parser';
 import createAvaRule from '../create-ava-rule.js';
 
@@ -17,14 +16,10 @@ const rule = {
 	},
 };
 
-const ruleTester = new AvaRuleTester(test, {
-	languageOptions: {
-		ecmaVersion: 'latest',
-		sourceType: 'module',
-	},
-});
+const ruleTester = new RuleTester({autoHeader: false});
 
-const typescriptRuleTester = new AvaRuleTester(test, {
+const typescriptRuleTester = new RuleTester({
+	autoHeader: false,
 	languageOptions: {
 		parser: tsParser,
 	},
@@ -37,9 +32,6 @@ const errors = [
 ];
 
 ruleTester.run('rule-fixture', rule, {
-	assertionOptions: {
-		requireMessage: true,
-	},
 	valid: [
 		// `require` patterns
 		'const test = require(\'ava\');',
@@ -76,9 +68,6 @@ ruleTester.run('rule-fixture', rule, {
 });
 
 typescriptRuleTester.run('rule-fixture-ts', rule, {
-	assertionOptions: {
-		requireMessage: true,
-	},
 	valid: [
 		// TypeScript re-assignment patterns
 		{name: 'as assertion', code: 'import anyTest from \'ava\';\nconst test = anyTest as any;'},

test/failing-test-url.js

@@ -1,49 +1,43 @@
-import test from 'ava';
-import AvaRuleTester from 'eslint-ava-rule-tester';
+import RuleTester from './helpers/rule-tester.js';
 import rule from '../rules/failing-test-url.js';
 
-const ruleTester = new AvaRuleTester(test, {
-	languageOptions: {
-		ecmaVersion: 'latest',
-	},
-});
+const ruleTester = new RuleTester();
 
 const messageId = 'failing-test-url';
-const header = 'const test = require(\'ava\');\n';
 
 ruleTester.run('failing-test-url', rule, {
 	valid: [
-		header + 'test("my test name", t => { t.pass(); });',
-		header + '// https://github.com/avajs/ava/issues/123\ntest.failing(t => { t.pass(); });',
-		header + '/* https://github.com/avajs/ava/issues/123 */\ntest.failing(t => { t.pass(); });',
-		header + '// See http://example.com/issue\ntest.failing(t => { t.pass(); });',
-		header + '// Tracking issue: https://github.com/avajs/ava/issues/123\ntest.failing(t => { t.pass(); });',
-		header + '// https://github.com/avajs/ava/issues/123\ntest.serial.failing(t => { t.pass(); });',
+		'test("my test name", t => { t.pass(); });',
+		'// https://github.com/avajs/ava/issues/123\ntest.failing(t => { t.pass(); });',
+		'/* https://github.com/avajs/ava/issues/123 */\ntest.failing(t => { t.pass(); });',
+		'// See http://example.com/issue\ntest.failing(t => { t.pass(); });',
+		'// Tracking issue: https://github.com/avajs/ava/issues/123\ntest.failing(t => { t.pass(); });',
+		'// https://github.com/avajs/ava/issues/123\ntest.serial.failing(t => { t.pass(); });',
 		// Not a test file
-		'test.failing(t => { t.pass(); });',
+		{code: 'test.failing(t => { t.pass(); });', noHeader: true},
 		// Not a test call
-		header + 'notTest.failing();',
+		'notTest.failing();',
 	],
 	invalid: [
 		{
-			code: header + 'test.failing(t => { t.pass(); });',
+			code: 'test.failing(t => { t.pass(); });',
 			errors: [{messageId, line: 2, column: 6}],
 		},
 		{
-			code: header + '// TODO: fix this\ntest.failing(t => { t.pass(); });',
+			code: '// TODO: fix this\ntest.failing(t => { t.pass(); });',
 			errors: [{messageId, line: 3, column: 6}],
 		},
 		{
-			code: header + 'test.serial.failing(t => { t.pass(); });',
+			code: 'test.serial.failing(t => { t.pass(); });',
 			errors: [{messageId, line: 2, column: 13}],
 		},
 		{
-			code: header + '// See issue #123\ntest.failing(t => { t.pass(); });',
+			code: '// See issue #123\ntest.failing(t => { t.pass(); });',
 			errors: [{messageId, line: 3, column: 6}],
 		},
 		{
 			// URL comment separated by code should not count
-			code: header + '// https://github.com/avajs/ava/issues/123\nconst foo = 1;\ntest.failing(t => { t.pass(); });',
+			code: '// https://github.com/avajs/ava/issues/123\nconst foo = 1;\ntest.failing(t => { t.pass(); });',
 			errors: [{messageId, line: 4, column: 6}],
 		},
 	],

test/helpers/rule-tester.js

@@ -0,0 +1,87 @@
+import path from 'node:path';
+import test from 'ava';
+import AvaRuleTester from 'eslint-ava-rule-tester';
+
+const header = 'import test from \'ava\';\n';
+
+function addHeaderToCase(testCase) {
+	if (typeof testCase === 'string') {
+		return header + testCase;
+	}
+
+	if (testCase.noHeader) {
+		const {noHeader, ...rest} = testCase;
+		return rest;
+	}
+
+	const result = {...testCase, code: header + testCase.code};
+
+	if (typeof result.output === 'string') {
+		result.output = header + result.output;
+	}
+
+	result.errors &&= result.errors.map(error => {
+		if (!error.suggestions) {
+			return error;
+		}
+
+		return {
+			...error,
+			suggestions: error.suggestions.map(suggestion => typeof suggestion.output === 'string'
+				? {...suggestion, output: header + suggestion.output}
+				: suggestion),
+		};
+	});
+
+	return result;
+}
+
+const defaultConfig = {
+	languageOptions: {
+		ecmaVersion: 'latest',
+		sourceType: 'module',
+	},
+};
+
+export default class RuleTester extends AvaRuleTester {
+	#autoHeader;
+
+	constructor({autoHeader, ...config} = {}) {
+		super(test, {
+			...defaultConfig,
+			...config,
+			languageOptions: {
+				...defaultConfig.languageOptions,
+				...config.languageOptions,
+			},
+		});
+		this.#autoHeader = autoHeader ?? true;
+	}
+
+	run(name, rule, tests) {
+		const processed = this.#autoHeader
+			? {
+				valid: tests.valid.map(testCase => addHeaderToCase(testCase)),
+				invalid: tests.invalid.map(testCase => addHeaderToCase(testCase)),
+			}
+			: {};
+
+		return super.run(name, rule, {
+			assertionOptions: {requireMessage: true},
+			...tests,
+			...processed,
+		});
+	}
+}
+
+export function testCase(contents) {
+	return `test(t => { ${contents} });`;
+}
+
+export function asyncTestCase(contents) {
+	return `test(async t => { ${contents} });`;
+}
+
+export const toPath = subPath => path.join(path.dirname(path.dirname(import.meta.dirname)), subPath);
+
+export {header};