Chore: Add test that deprecated rules display a deprecated notice

Makefile.js

@@ -816,6 +816,20 @@ target.checkRuleFiles = function() {
             return idNewAtBeginningOfTitleRegExp.test(docText) || idOldAtEndOfTitleRegExp.test(docText);
         }
 
+        /**
+         * Check if deprecated information is in rule code and READNE.md.
+         * @returns {boolean} true if present
+         * @private
+         */
+        function hasDeprecatedInfo() {
+            const ruleCode = cat(filename);
+            const deprecatedTagRegExp = /@deprecated in ESLint/u;
+            const docText = cat(docFilename);
+            const deprecatedInfoRegExp = /This rule was .+deprecated.+in ESLint/u;
+
+            return deprecatedTagRegExp.test(ruleCode) && deprecatedInfoRegExp.test(docText);
+        }
+
         // check for docs
         if (!test("-f", docFilename)) {
             console.error("Missing documentation for rule %s", basename);
@@ -842,12 +856,17 @@ target.checkRuleFiles = function() {
         if (!ruleDef) {
             console.error(`Missing rule from index (./lib/rules/index.js): ${basename}. If you just added a new rule then add an entry for it in this file.`);
             errors++;
-        }
+        } else {
+
+            // check deprecated
+            if (ruleDef.meta.deprecated && !hasDeprecatedInfo()) {
+                console.error(`Missing deprecated information in ${basename} rule code or README.md. Please write @deprecated tag in code or 「This rule was deprecated in ESLint ...」 in README.md.`);
+                errors++;
+            }
 
-        // check eslint:recommended
-        const recommended = require("./conf/eslint-recommended");
+            // check eslint:recommended
+            const recommended = require("./conf/eslint-recommended");
 
-        if (ruleDef) {
             if (ruleDef.meta.docs.recommended) {
                 if (recommended.rules[basename] !== "error") {
                     console.error(`Missing rule from eslint:recommended (./conf/eslint-recommended.js): ${basename}. If you just made a rule recommended then add an entry for it in this file.`);

docs/rules/indent-legacy.md

@@ -1,5 +1,6 @@
 # enforce consistent indentation (indent-legacy)
 
+This rule was **deprecated** in ESLint v4.0.0.
 ESLint 4.0.0 introduced a rewrite of the [`indent`](/docs/rules/indent) rule, which now reports more errors than it did in previous versions. To ease the process of migrating to 4.0.0, the `indent-legacy` rule was introduced as a snapshot of the `indent` rule from ESLint 3.x. If your build is failing after the upgrade to 4.0.0, you can disable `indent` and enable `indent-legacy` as a quick fix. Eventually, you should switch back to the `indent` rule to get bugfixes and improvements in future versions.
 
 ---