eslint 6 support

.travis.yml

@@ -3,29 +3,36 @@ language: node_js
 notifications:
   email: false
 node_js:
+  - '12'
   - '10'
   - '8'
-  - '6'
-  - '4'
 before_install:
   - nvm install-latest-npm
 before_script:
   - 'if [ -n "${ESLINT-}" ]; then npm install --no-save "eslint@${ESLINT}"; fi'
   - 'if [ -n "${AJV-}" ]; then npm install --no-save "ajv@${AJV}"; fi'
-  - npm ls > /dev/null
+  - npm prune > /dev/null && npm ls > /dev/null
 script:
   - 'if [ -n "${LINTONLY-}" ]; then npm run lint; else npm run cover && npm run check-coverage; fi'
 after_success:
   - npm run travis-after-all
 env:
   matrix:
+   - ESLINT=6
    - ESLINT=5 AJV=6
    - ESLINT=4 AJV=5
    - ESLINT=3
 matrix:
   include:
     - node_js: "node"
       env: LINTONLY=true
-  exclude:
+    - node_js: "6"
+      env: ESLINT=5 AJV=5
+    - node_js: "6"
+      env: ESLINT=4 AJV=5
+    - node_js: "6"
+      env: ESLINT=3
     - node_js: "4"
-      env: ESLINT=5 AJV=6
+      env: ESLINT=4 AJV=5
+    - node_js: "4"
+      env: ESLINT=3

package.json

@@ -4,7 +4,7 @@
   "description": "Find built-in ESLint rules you don't have in your custom config.",
   "main": "dist/lib/rule-finder.js",
   "scripts": {
-    "cover": "nyc --reporter=lcov --reporter=text npm test",
+    "cover": "nyc --reporter=lcov --reporter=text --reporter=html npm test",
     "lint": "eslint --ext .js,.json .",
     "test": "mocha --recursive",
     "update-contributors": "all-contributors generate",
@@ -32,6 +32,7 @@
   "dependencies": {
     "cliui": "^3.2.0",
     "eslint-rule-documentation": "^1.0.0",
+    "glob": "^7.1.4",
     "path-is-absolute": "^1.0.1",
     "which": "^1.2.8",
     "window-size": "0.3.0",
@@ -46,7 +47,7 @@
     "codecov": "^2.2.0",
     "commitizen": "^2.9.6",
     "cz-conventional-changelog": "^2.0.0",
-    "eslint": "^3.12.0 || ^4 || ^5",
+    "eslint": "^3.12.0 || ^4 || ^5 || ^6",
     "eslint-plugin-json": "^1.4.0",
     "ghooks": "^2.0.0",
     "mocha": "^3.0.1",
@@ -60,7 +61,7 @@
     "validate-commit-msg": "^2.12.2"
   },
   "peerDependencies": {
-    "eslint": "^3.12.0 || ^4 || ^5"
+    "eslint": "^3.12.0 || ^4 || ^5 || ^6"
   },
   "nyc": {
     "exclude": [

src/lib/rule-finder.js

@@ -1,6 +1,7 @@
 const path = require('path');
 
 const eslint = require('eslint');
+const glob = require('glob');
 const isAbsolute = require('path-is-absolute');
 const difference = require('./array-diff');
 const getSortedRules = require('./sort-rules');
@@ -16,14 +17,22 @@ function _getConfigFile(specifiedFile) {
   return require(path.join(process.cwd(), 'package.json')).main; // eslint-disable-line import/no-dynamic-require
 }
 
-function _getConfig(configFile) {
+function _getConfigs(configFile, files) {
   const cliEngine = new eslint.CLIEngine({
     // Ignore any config applicable depending on the location on the filesystem
     useEslintrc: false,
     // Point to the particular config
     configFile
   });
-  return cliEngine.getConfigForFile();
+  return new Set(files
+                 .map(filePath => cliEngine.isPathIgnored(filePath) ? false : cliEngine.getConfigForFile(filePath))
+                 .filter(Boolean));
+}
+
+function _getConfig(configFile, files) {
+  return Array.from(_getConfigs(configFile, files)).reduce((prev, item) => {
+    return Object.assign(prev, item, {rules: Object.assign({}, prev.rules, item.rules)});
+  }, {});
 }
 
 function _getCurrentNamesRules(config) {
@@ -69,6 +78,7 @@ function _notDeprecated(rule) {
 function _getPluginRules(config) {
   const pluginRules = new Map();
   const plugins = config.plugins;
+  /* istanbul ignore else */
   if (plugins) {
     plugins.forEach(plugin => {
       const normalized = _normalizePluginName(plugin);
@@ -98,7 +108,8 @@ function _isNotCore(rule) {
 function RuleFinder(specifiedFile, options) {
   const {omitCore, includeDeprecated} = options;
   const configFile = _getConfigFile(specifiedFile);
-  const config = _getConfig(configFile);
+  const files = glob.sync('**/*.js', {dot: true, matchBase: true});
+  const config = _getConfig(configFile, files);
   let currentRuleNames = _getCurrentNamesRules(config);
   if (omitCore) {
     currentRuleNames = currentRuleNames.filter(_isNotCore);

test/lib/rule-finder.js

@@ -2,6 +2,21 @@ const path = require('path');
 const assert = require('assert');
 const proxyquire = require('proxyquire');
 
+let ModuleResolver;
+try {
+  // eslint 6 and over: load the actual module
+  // eslint-disable-next-line import/no-unresolved
+  ModuleResolver = require('eslint/lib/shared/relative-module-resolver');
+} catch (err) {
+  if (err.code !== 'MODULE_NOT_FOUND') {
+    throw err;
+  }
+  // eslint < 6: ModuleResolver is `undefined`, which is okay. The proxyquire
+  // override for ../shared/relative-module-resolver won't be used because
+  // eslint < 6 does not have that module and so does not try to load it.
+  ModuleResolver = undefined;
+}
+
 const processCwd = process.cwd;
 
 const eslintVersion = process.env.ESLINT === '3' || process.env.ESLINT === '4' ? '<v5' : 'v5+';
@@ -19,6 +34,31 @@ const getRuleFinder = proxyquire('../../src/lib/rule-finder', {
       }
     }
   },
+  //
+  // This following module override is needed for eslint v6 and over. The module
+  // path that we pass here is literally the one used in eslint (specifially in
+  // eslint/lib/cli-engine/config-array-factory.js)
+  //
+  // The stock `resolve` method attempts to resolve to a file path the module
+  // name passed in `name` relative to the path in `relative`. We have to
+  // override that function, otherwise eslint fails to "load" our plugins.
+  //
+  '../shared/relative-module-resolver': {
+    resolve(name, relative) {
+      // The strategy is simple: if called with one of our plugins, just return
+      // the module name, as-is. This is a lie because what we return is not a
+      // path, but it is simple, and works. Otherwise, we just call the original
+      // `resolve` from the stock module.
+      return ['eslint-plugin-plugin',
+        'eslint-plugin-no-rules',
+        '@scope/eslint-plugin-scoped-plugin',
+        '@scope/eslint-plugin'].includes(name) ?
+        name :
+        ModuleResolver.resolve(name, relative);
+    },
+    '@global': true,
+    '@noCallThru': true
+  },
   'eslint-plugin-plugin': {
     rules: {
       'foo-rule': {},
@@ -83,6 +123,17 @@ const getRuleFinderForDedupeTests = proxyquire('../../src/lib/rule-finder', {
       }
     }
   },
+  // See the long comment in `getRuleFinder` above to learn what the point of
+  // this override is.
+  '../shared/relative-module-resolver': {
+    resolve(name, relative) {
+      return name === 'eslint-plugin-plugin' ?
+        name :
+        ModuleResolver.resolve(name, relative);
+    },
+    '@global': true,
+    '@noCallThru': true
+  },
   'eslint-plugin-plugin': {
     rules: {
       'duplicate-foo-rule': {},