feat(rule-finder): add --ext option

README.md

@@ -46,7 +46,7 @@ Then run it with: `$ npm run --silent eslint-find-option-rules` (the `--silent`
 
 ```
 available options are -a|--all-available, -c|--current, -d|--deprecated, -p|--plugin, -u|--unused
-available flags are -n|--no-error, --no-core, and -i/--include deprecated
+available flags are -n|--no-error, --no-core, -i/--include deprecated, and --ext .js
 ```
 
 By default it will error out only for `-d|--deprecated` and `-u|--unused`,
@@ -56,6 +56,8 @@ By default, core rules will be included in the output of `-a|--all-available`, `
 
 By default, deprecated rules will be omitted from the output of `-a|--all-available`, `-p|--plugin` and `-u|--unused`.  If you want to report on deprecated rules as well, use the `--include=deprecated` or `-i deprecated` flag.
 
+By default, rules will be searched for files having `.js` extension.  If you want to find rules using another extension (`.json` for example), use the `--ext .json` flag (or `--ext .js --ext .json` if you need multiple extensions).
+
 **NOTE:** Deprecated rules are found by looking at the metadata of the rule definition.  All core rules and many plugin rules use this flag to indicate deprecated rules.  But if you find a plugin that does not mark their rules as deprecated in the rule metadata, please file a pull request with that project.
 
 ### Specify a file

src/bin/find.js

@@ -22,6 +22,10 @@ const argv = require('yargs')
     choices: ['deprecated'],
     type: 'string'
   })
+  .option('ext', {
+    type: 'array',
+    default: ['.js']
+  })
   .default('error', true)
   .default('core', true)
   .argv;
@@ -32,7 +36,8 @@ const cli = require('../lib/cli-util');
 const specifiedFile = argv._[0];
 const finderOptions = {
   omitCore: !argv.core,
-  includeDeprecated: argv.include === 'deprecated'
+  includeDeprecated: argv.include === 'deprecated',
+  ext: argv.ext
 };
 const ruleFinder = getRuleFinder(specifiedFile, finderOptions);
 const errorOut = argv.error && !argv.n;

src/lib/rule-finder.js

@@ -37,7 +37,7 @@ function _getConfig(configFile, files) {
 }
 
 function _getCurrentNamesRules(config) {
-  return Object.keys(config.rules);
+  return config.rules ? Object.keys(config.rules) : [];
 }
 
 function _isDeprecated(rule) {
@@ -78,10 +78,30 @@ function _isNotCore(rule) {
   return rule.indexOf('/') !== '-1';
 }
 
-function RuleFinder(specifiedFile, options) {
-  const {omitCore, includeDeprecated} = options;
+function _escapeRegExp(str) {
+  return str.replace(/[\\^$.*+?()[\]{}|]/ug, '\\$&');
+}
+
+function _createExtensionRegExp(extensions) {
+  const normalizedExts = extensions.map(ext => _escapeRegExp(
+    ext.startsWith(".")
+      ? ext.slice(1)
+      : ext
+  ));
+
+  return new RegExp(
+    `.\\.(?:${normalizedExts.join("|")})$`,
+    "u"
+  );
+}
+
+function RuleFinder(specifiedFile, {omitCore, includeDeprecated, ext = ['.js']}) {
   const configFile = _getConfigFile(specifiedFile);
-  const files = glob.sync('**/*.js', {dot: true, matchBase: true});
+
+  const extensionRegExp = _createExtensionRegExp(ext);
+  const files = glob.sync(`**/*`, {dot: true, matchBase: true})
+    .filter(file => extensionRegExp.test(file));
+
   const config = _getConfig(configFile, files);
   let currentRuleNames = _getCurrentNamesRules(config);
   if (omitCore) {

test/bin/find.js

@@ -87,6 +87,23 @@ describe('bin', () => {
     assert.equal(exitStatus, 0);
   });
 
+  it('option -a along with --ext', () => {
+    process.argv[2] = '-a';
+    process.argv[3] = '--ext .json';
+    proxyquire('../../src/bin/find', stub);
+    assert.ok(getAllAvailableRules.called);
+    assert.equal(exitStatus, 0);
+  });
+
+  it('option -a along with multi --ext', () => {
+    process.argv[2] = '-a';
+    process.argv[3] = '--ext .js';
+    process.argv[4] = '--ext .json';
+    proxyquire('../../src/bin/find', stub);
+    assert.ok(getAllAvailableRules.called);
+    assert.equal(exitStatus, 0);
+  });
+
   it('option -u|--unused', () => {
     process.argv[2] = '-u';
     proxyquire('../../src/bin/find', stub);

test/lib/rule-finder.js

@@ -290,6 +290,35 @@ describe('rule-finder', function() {
     ]);
   });
 
+  it('specifiedFile (relative path) - current rules with ext', () => {
+    const ruleFinder = getRuleFinder(specifiedFileRelative, { ext: ['.json'] });
+    assertDeepEqual(ruleFinder.getCurrentRules(), [
+      '@scope-with-dash/foo-rule',
+      '@scope-with-dash/scoped-with-dash-plugin/foo-rule',
+      '@scope/foo-rule',
+      '@scope/scoped-plugin/foo-rule',
+      'bar-rule',
+      'foo-rule'
+    ]);
+  });
+
+  it('specifiedFile (relative path) - current rules with ext without dot', () => {
+    const ruleFinder = getRuleFinder(specifiedFileRelative, { ext: ['json'] });
+    assertDeepEqual(ruleFinder.getCurrentRules(), [
+      '@scope-with-dash/foo-rule',
+      '@scope-with-dash/scoped-with-dash-plugin/foo-rule',
+      '@scope/foo-rule',
+      '@scope/scoped-plugin/foo-rule',
+      'bar-rule',
+      'foo-rule'
+    ]);
+  });
+
+  it('specifiedFile (relative path) - current rules with ext not found', () => {
+    const ruleFinder = getRuleFinder(specifiedFileRelative, { ext: ['.ts'] });
+    assertDeepEqual(ruleFinder.getCurrentRules(), []);
+  });
+
   it('specifiedFile (relative path) - current rule config', () => {
     const ruleFinder = getRuleFinder(specifiedFileRelative);
     assertDeepEqual(ruleFinder.getCurrentRulesDetailed(), {