Simplify rule deprecation (#956)

Author: fisker

docs/deprecated-rules.md

@@ -0,0 +1,9 @@
+# Deprecated Rules
+
+## prefer-exponentiation-operator
+
+This rule is deprecated in favor of the built-in ESLint [`prefer-exponentiation-operator`](https://eslint.org/docs/rules/prefer-exponentiation-operator) rule.
+
+## regex-shorthand
+
+This rule was renamed to [`better-regex`](rules/better-regex.md).

docs/rules/prefer-exponentiation-operator.md

@@ -1,9 +1,19 @@
 'use strict';
 const path = require('path');
 const importModules = require('import-modules');
+const createDeprecatedRules = require('./rules/utils/create-deprecated-rules');
+
+const deprecatedRules = createDeprecatedRules({
+	// {ruleId: ReplacementRuleId | ReplacementRuleId[]}, if no replacement, use `{ruleId: []}`
+	'prefer-exponentiation-operator': 'prefer-exponentiation-operator',
+	'regex-shorthand': 'unicorn/better-regex'
+});
 
 module.exports = {
-	rules: importModules(path.resolve(__dirname, 'rules'), {camelize: false}),
+	rules: {
+		...importModules(path.resolve(__dirname, 'rules'), {camelize: false}),
+		...deprecatedRules
+	},
 	configs: {
 		recommended: {
 			env: {

docs/rules/regex-shorthand.md

@@ -170,8 +170,7 @@ Configure it in `package.json`.
 
 ## Deprecated Rules
 
-- [prefer-exponentiation-operator](docs/rules/prefer-exponentiation-operator.md) - Use the built-in ESLint [`prefer-exponentiation-operator`](https://eslint.org/docs/rules/prefer-exponentiation-operator) rule instead.
-- [regex-shorthand](docs/rules/regex-shorthand.md) - Renamed to [`better-regex`](docs/rules/better-regex.md).
+See [docs/deprecated-rules.md](docs/deprecated-rules.md)
 
 ## Recommended config
 

index.js

@@ -0,0 +1,21 @@
+'use strict';
+const packageJson = require('../../package');
+const repoUrl = 'https://github.com/sindresorhus/eslint-plugin-unicorn';
+
+function createDeprecatedRules(data) {
+	const rules = {};
+	for (const [ruleId, replacedBy = []] of Object.entries(data)) {
+		rules[ruleId] = {
+			create: () => ({}),
+			meta: {
+				docs: {
+					url: `${repoUrl}/blob/v${packageJson.version}/docs/deprecated-rules.md#${ruleId}`
+				},
+				deprecated: true,
+				replacedBy: Array.isArray(replacedBy) ? replacedBy : [replacedBy]
+			}
+		};
+	}
+}
+
+module.exports = createDeprecatedRules;

readme.md

@@ -49,7 +49,7 @@ test('Every rule is defined in index file in alphabetical order', t => {
 		'There are more exported rules than rule files.'
 	);
 	t.is(
-		Object.keys(index.configs.recommended.rules).length - ignoredRules.length,
+		Object.keys(index.configs.recommended.rules).length - deprecatedRules.length - ignoredRules.length,
 		ruleFiles.length - deprecatedRules.length,
 		'There are more exported rules in the recommended config than rule files.'
 	);