Add testRuleConfigs function (#68)

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Head
+
+- Added: `testRuleConfigs` function.
+
 ## 6.1.1
 
 - Fixed: tightly-coupled dependency on Stylelint's internal module `lib/utils/getOsEol`.

README.md

@@ -2,7 +2,7 @@
 
 [![NPM version](https://img.shields.io/npm/v/jest-preset-stylelint.svg)](https://www.npmjs.org/package/jest-preset-stylelint) [![Build Status](https://github.com/stylelint/jest-preset-stylelint/workflows/CI/badge.svg)](https://github.com/stylelint/jest-preset-stylelint/actions)
 
-[Jest](https://facebook.github.io/jest/) preset for [Stylelint](https://github.com/stylelint) plugins.
+[Jest](https://jestjs.io/) preset for [Stylelint](https://stylelint.io/) plugins.
 
 ## Installation
 
@@ -22,14 +22,16 @@ Add the preset to your `jest.config.js` or `jest` field in `package.json`:
 }
 ```
 
-Optionally, you can avoid specifying `plugins` in every schema by defining your own setup file to configure the `testRule` function. This is useful if you have many tests. There are two additional steps to do this:
+Optionally, you can avoid specifying `plugins` in every schema by defining your own setup file to configure the `testRule`/`testRuleConfigs` functions.
+This is useful if you have many tests. There are two additional steps to do this:
 
-1. Create `jest.setup.js` in the root of your project. Provide `plugins` option to `getTestRule()`:
+1. Create `jest.setup.js` in the root of your project. Provide `plugins` option to `getTestRule`/`getTestRuleConfigs`:
 
    ```js
    const { getTestRule } = require("jest-preset-stylelint");
 
    global.testRule = getTestRule({ plugins: ["./"] });
+   global.testRuleConfigs = getTestRuleConfigs({ plugins: ["./"] });
    ```
 
 2. Add `jest.setup.js` to your `jest.config.js` or `jest` field in `package.json`:
@@ -43,7 +45,13 @@ Optionally, you can avoid specifying `plugins` in every schema by defining your
 
 ## Usage
 
-The preset exposes a global `testRule` function that you can use to efficiently test your plugin using a schema.
+This preset exposes the following global functions as a helper.
+
+See also the [type definitions](index.d.ts) for more details.
+
+### `testRule`
+
+The `testRule` function enables you to efficiently test your plugin using a schema.
 
 For example, we can test a plugin that enforces and autofixes kebab-case class selectors:
 
@@ -104,9 +112,34 @@ testRule({
 });
 ```
 
-## Schema properties
+### `testRuleConfigs`
+
+The `testRuleConfigs` function enables you to test invalid configs for a rule.
+
+For example:
+
+```js
+testInvalidRuleConfigs({
+  plugins: ["."],
+  ruleName,
+
+  accept: [
+    {
+      config: "valid"
+    }
+  ],
 
-See the [type definitions](index.d.ts).
+  reject: [
+    {
+      config: "invalid"
+    },
+    {
+      config: [/invalid/],
+      description: "regex is not allowed"
+    }
+  ]
+});
+```
 
 ## [Changelog](CHANGELOG.md)
 

__tests__/fixtures/plugin-foo.js

@@ -0,0 +1,44 @@
+'use strict';
+
+const stylelint = require('stylelint');
+
+const ruleName = 'plugin/foo';
+
+const messages = stylelint.utils.ruleMessages(ruleName, {
+	rejected: (selector) => `No "${selector}" selector`,
+});
+
+/** @type {(value: unknown) => boolean} */
+const isString = (value) => typeof value === 'string';
+
+/** @type {import('stylelint').Rule} */
+const ruleFunction = (primary) => {
+	return (root, result) => {
+		const validOptions = stylelint.utils.validateOptions(result, ruleName, {
+			actual: primary,
+			possible: [isString],
+		});
+
+		if (!validOptions) {
+			return;
+		}
+
+		root.walkRules((rule) => {
+			const { selector } = rule;
+
+			if (primary !== selector) {
+				stylelint.utils.report({
+					result,
+					ruleName,
+					message: messages.rejected(selector),
+					node: rule,
+				});
+			}
+		});
+	};
+};
+
+ruleFunction.ruleName = ruleName;
+ruleFunction.messages = messages;
+
+module.exports = stylelint.createPlugin(ruleName, ruleFunction);

__tests__/getTestRule.test.js

@@ -0,0 +1,33 @@
+'use strict';
+
+const getTestRule = require('../getTestRule.js');
+
+const testRule = getTestRule();
+
+testRule({
+	plugins: [require.resolve('./fixtures/plugin-foo.js')],
+	ruleName: 'plugin/foo',
+	config: ['.a'],
+
+	accept: [
+		{
+			code: '.a {}',
+		},
+		{
+			code: '.a {}',
+			description: 'with description',
+		},
+	],
+
+	reject: [
+		{
+			code: '#a {}',
+			message: 'No "#a" selector (plugin/foo)',
+		},
+		{
+			code: '#a {}',
+			message: 'No "#a" selector (plugin/foo)',
+			description: 'with description',
+		},
+	],
+});

__tests__/getTestRuleConfigs.test.js

@@ -0,0 +1,30 @@
+'use strict';
+
+const getTestRuleConfigs = require('../getTestRuleConfigs.js');
+
+const testRuleConfigs = getTestRuleConfigs();
+
+testRuleConfigs({
+	plugins: [require.resolve('./fixtures/plugin-foo.js')],
+	ruleName: 'plugin/foo',
+
+	accept: [
+		{
+			config: 'a',
+		},
+		{
+			config: ['b'],
+			description: 'string is allowed',
+		},
+	],
+
+	reject: [
+		{
+			config: 123,
+		},
+		{
+			config: [/foo/],
+			description: 'regex is not allowed',
+		},
+	],
+});

getTestRuleConfigs.js

@@ -0,0 +1,68 @@
+'use strict';
+
+const { inspect } = require('util');
+
+/** @type {import('.').getTestRuleConfigs} */
+module.exports = function getTestRuleConfigs(options = {}) {
+	return function testRuleConfigs({
+		ruleName,
+		accept = [],
+		reject = [],
+		only = false,
+		skip = false,
+		plugins = options.plugins,
+	}) {
+		if (accept.length === 0 && reject.length === 0) {
+			throw new TypeError('The either "accept" or "reject" property must not be empty');
+		}
+
+		/** @type {import('stylelint').lint} */
+		let lint;
+
+		beforeAll(() => {
+			// eslint-disable-next-line n/no-unpublished-require
+			lint = require('stylelint').lint;
+		});
+
+		const testGroup = only ? describe.only : skip ? describe.skip : describe;
+
+		testGroup(`${ruleName} configs`, () => {
+			/**
+			 * @param {import('.').ConfigCase} case
+			 * @param {(warnings: unknown[]) => void} comparison
+			 */
+			function testConfig({ config, description, only: onlyTest, skip: skipTest }, comparison) {
+				const testFn = onlyTest ? test.only : skipTest ? test.skip : test;
+
+				testFn(`${description || inspect(config)}`, async () => {
+					const lintConfig = {
+						plugins,
+						rules: { [ruleName]: config },
+					};
+					const { results } = await lint({ code: '', config: lintConfig });
+
+					expect(results).toHaveLength(1);
+					comparison(results[0].invalidOptionWarnings);
+				});
+			}
+
+			describe('accept', () => {
+				accept.forEach((c) => {
+					testConfig(c, (warnings) => {
+						// eslint-disable-next-line jest/no-standalone-expect
+						expect(warnings).toEqual([]);
+					});
+				});
+			});
+
+			describe('reject', () => {
+				reject.forEach((c) => {
+					testConfig(c, (warnings) => {
+						// eslint-disable-next-line jest/no-standalone-expect
+						expect(warnings).toEqual([{ text: expect.stringMatching(`"${ruleName}"`) }]);
+					});
+				});
+			});
+		});
+	};
+};

index.d.ts

@@ -156,6 +156,29 @@ export type TestRule = (schema: TestSchema) => void;
  */
 export function getTestRule(options?: { plugins?: TestSchema['plugins'] }): TestRule;
 
+export type ConfigCase = {
+	config: unknown;
+	description?: string;
+	only?: boolean;
+	skip?: boolean;
+};
+
+/**
+ * Test configurations for a rule.
+ */
+export type TestRuleConfigs = (
+	schema: Pick<TestSchema, 'ruleName' | 'plugins' | 'only' | 'skip'> & {
+		accept?: ConfigCase[];
+		reject?: ConfigCase[];
+	},
+) => void;
+
+/**
+ * Create a `testRuleConfigs()` function with any specified plugins.
+ */
+export function getTestRuleConfigs(options?: { plugins?: TestSchema['plugins'] }): TestRuleConfigs;
+
 declare global {
 	var testRule: TestRule;
+	var testRuleConfigs: TestRuleConfigs;
 }

jest-setup.js

@@ -1,5 +1,7 @@
 'use strict';
 
-const getTestRule = require('./getTestRule');
+const getTestRule = require('./getTestRule.js');
+const getTestRuleConfigs = require('./getTestRuleConfigs.js');
 
 global.testRule = getTestRule();
+global.testRuleConfigs = getTestRuleConfigs();

package.json

@@ -14,6 +14,7 @@
   "main": "index.js",
   "types": "index.d.ts",
   "files": [
+    "getTestRuleConfigs.js",
     "getTestRule.js",
     "jest-preset.js",
     "jest-setup.js",
@@ -55,6 +56,10 @@
       "@stylelint/remark-preset"
     ]
   },
+  "jest": {
+    "preset": "./jest-preset.js",
+    "testRegex": ".*\\.test\\.js$"
+  },
   "devDependencies": {
     "@stylelint/prettier-config": "^3.0.0",
     "@stylelint/remark-preset": "^4.0.0",