tools: update to ESLint 4.3.0

.eslintrc.yaml

@@ -102,17 +102,17 @@ rules:
   func-name-matching: error
   func-style: [error, declaration, {allowArrowFunctions: true}]
   # indent: [error, 2, {ArrayExpression: first,
-  #                 CallExpression: {arguments: first},
-  #                 FunctionDeclaration: {parameters: first},
-  #                 FunctionExpression: {parameters: first},
-  #                 MemberExpression: off,
-  #                 ObjectExpression: first,
-  #                 SwitchCase: 1}]
+  #                     CallExpression: {arguments: first},
+  #                     FunctionDeclaration: {parameters: first},
+  #                     FunctionExpression: {parameters: first},
+  #                     MemberExpression: off,
+  #                     ObjectExpression: first,
+  #                     SwitchCase: 1}]
   indent-legacy: [error, 2, {ArrayExpression: first,
-                         CallExpression: {arguments: first},
-                         MemberExpression: 1,
-                         ObjectExpression: first,
-                         SwitchCase: 1}]
+                             CallExpression: {arguments: first},
+                             MemberExpression: 1,
+                             ObjectExpression: first,
+                             SwitchCase: 1}]
   key-spacing: [error, {mode: minimum}]
   keyword-spacing: error
   linebreak-style: [error, unix]

lib/async_hooks.js

@@ -40,7 +40,8 @@ var tmp_async_hook_fields = null;
 // async execution. These are tracked so if the user didn't include callbacks
 // for a given step, that step can bail out early.
 const { kInit, kBefore, kAfter, kDestroy, kTotals, kCurrentAsyncId,
-  kCurrentTriggerId, kAsyncUidCntr, kInitTriggerId } = async_wrap.constants;
+        kCurrentTriggerId, kAsyncUidCntr,
+        kInitTriggerId } = async_wrap.constants;
 
 const { async_id_symbol, trigger_id_symbol } = async_wrap;
 

lib/child_process.js

@@ -24,7 +24,7 @@
 const util = require('util');
 const { deprecate, convertToValidSignal } = require('internal/util');
 const { createPromise,
-  promiseResolve, promiseReject } = process.binding('util');
+        promiseResolve, promiseReject } = process.binding('util');
 const debug = util.debuglog('child_process');
 
 const uv = process.binding('uv');

tools/eslint/bin/eslint.js

@@ -44,11 +44,10 @@ process.once("uncaughtException", err => {
     if (typeof err.messageTemplate === "string" && err.messageTemplate.length > 0) {
         const template = lodash.template(fs.readFileSync(path.resolve(__dirname, `../messages/${err.messageTemplate}.txt`), "utf-8"));
 
-        console.log("\nOops! Something went wrong! :(");
-        console.log(`\n${template(err.messageData || {})}`);
+        console.error("\nOops! Something went wrong! :(");
+        console.error(`\n${template(err.messageData || {})}`);
     } else {
-        console.log(err.message);
-        console.log(err.stack);
+        console.error(err.stack);
     }
 
     process.exitCode = 1;

tools/eslint/lib/config/config-initializer.js

@@ -12,10 +12,12 @@
 const util = require("util"),
     inquirer = require("inquirer"),
     ProgressBar = require("progress"),
+    semver = require("semver"),
     autoconfig = require("./autoconfig.js"),
     ConfigFile = require("./config-file"),
     ConfigOps = require("./config-ops"),
     getSourceCodeOfFiles = require("../util/source-code-util").getSourceCodeOfFiles,
+    ModuleResolver = require("../util/module-resolver"),
     npmUtil = require("../util/npm-util"),
     recConfig = require("../../conf/eslint-recommended"),
     log = require("../logging");
@@ -56,12 +58,35 @@ function writeFile(config, format) {
     }
 }
 
+/**
+ * Get the peer dependencies of the given module.
+ * This adds the gotten value to cache at the first time, then reuses it.
+ * In a process, this function is called twice, but `npmUtil.fetchPeerDependencies` needs to access network which is relatively slow.
+ * @param {string} moduleName The module name to get.
+ * @returns {Object} The peer dependencies of the given module.
+ * This object is the object of `peerDependencies` field of `package.json`.
+ */
+function getPeerDependencies(moduleName) {
+    let result = getPeerDependencies.cache.get(moduleName);
+
+    if (!result) {
+        log.info(`Checking peerDependencies of ${moduleName}`);
+
+        result = npmUtil.fetchPeerDependencies(moduleName);
+        getPeerDependencies.cache.set(moduleName, result);
+    }
+
+    return result;
+}
+getPeerDependencies.cache = new Map();
+
 /**
  * Synchronously install necessary plugins, configs, parsers, etc. based on the config
  * @param   {Object} config  config object
+ * @param   {boolean} [installESLint=true]  If `false` is given, it does not install eslint.
  * @returns {void}
  */
-function installModules(config) {
+function installModules(config, installESLint) {
     const modules = {};
 
     // Create a list of modules which should be installed based on config
@@ -73,11 +98,10 @@ function installModules(config) {
     if (config.extends && config.extends.indexOf("eslint:") === -1) {
         const moduleName = `eslint-config-${config.extends}`;
 
-        log.info(`Checking peerDependencies of ${moduleName}`);
         modules[moduleName] = "latest";
         Object.assign(
             modules,
-            npmUtil.fetchPeerDependencies(`${moduleName}@latest`)
+            getPeerDependencies(`${moduleName}@latest`)
         );
     }
 
@@ -86,15 +110,17 @@ function installModules(config) {
         return;
     }
 
-    // Add eslint to list in case user does not have it installed locally
-    modules.eslint = modules.eslint || "latest";
-
-    // Mark to show messages if it's new installation of eslint.
-    const installStatus = npmUtil.checkDevDeps(["eslint"]);
+    if (installESLint === false) {
+        delete modules.eslint;
+    } else {
+        const installStatus = npmUtil.checkDevDeps(["eslint"]);
 
-    if (installStatus.eslint === false) {
-        log.info("Local ESLint installation not found.");
-        config.installedESLint = true;
+        // Mark to show messages if it's new installation of eslint.
+        if (installStatus.eslint === false) {
+            log.info("Local ESLint installation not found.");
+            modules.eslint = modules.eslint || "latest";
+            config.installedESLint = true;
+        }
     }
 
     // Install packages
@@ -265,9 +291,10 @@ function processAnswers(answers) {
 /**
  * process user's style guide of choice and return an appropriate config object.
  * @param {string} guide name of the chosen style guide
+ * @param {boolean} [installESLint=true]  If `false` is given, it does not install eslint.
  * @returns {Object} config object
  */
-function getConfigForStyleGuide(guide) {
+function getConfigForStyleGuide(guide, installESLint) {
     const guides = {
         google: { extends: "google" },
         airbnb: { extends: "airbnb" },
@@ -279,11 +306,74 @@ function getConfigForStyleGuide(guide) {
         throw new Error("You referenced an unsupported guide.");
     }
 
-    installModules(guides[guide]);
+    installModules(guides[guide], installESLint);
 
     return guides[guide];
 }
 
+/**
+ * Get the version of the local ESLint.
+ * @returns {string|null} The version. If the local ESLint was not found, returns null.
+ */
+function getLocalESLintVersion() {
+    try {
+        const resolver = new ModuleResolver();
+        const eslintPath = resolver.resolve("eslint", process.cwd());
+        const eslint = require(eslintPath);
+
+        return eslint.linter.version || null;
+    } catch (_err) {
+        return null;
+    }
+}
+
+/**
+ * Get the shareable config name of the chosen style guide.
+ * @param {Object} answers The answers object.
+ * @returns {string} The shareable config name.
+ */
+function getStyleGuideName(answers) {
+    if (answers.styleguide === "airbnb" && !answers.airbnbReact) {
+        return "airbnb-base";
+    }
+    return answers.styleguide;
+}
+
+/**
+ * Check whether the local ESLint version conflicts with the required version of the chosen shareable config.
+ * @param {Object} answers The answers object.
+ * @returns {boolean} `true` if the local ESLint is found then it conflicts with the required version of the chosen shareable config.
+ */
+function hasESLintVersionConflict(answers) {
+
+    // Get the local ESLint version.
+    const localESLintVersion = getLocalESLintVersion();
+
+    if (!localESLintVersion) {
+        return false;
+    }
+
+    // Get the required range of ESLint version.
+    const configName = getStyleGuideName(answers);
+    const moduleName = `eslint-config-${configName}@latest`;
+    const requiredESLintVersionRange = getPeerDependencies(moduleName).eslint;
+
+    if (!requiredESLintVersionRange) {
+        return false;
+    }
+
+    answers.localESLintVersion = localESLintVersion;
+    answers.requiredESLintVersionRange = requiredESLintVersionRange;
+
+    // Check the version.
+    if (semver.satisfies(localESLintVersion, requiredESLintVersionRange)) {
+        answers.installESLint = false;
+        return false;
+    }
+
+    return true;
+}
+
 /* istanbul ignore next: no need to test inquirer*/
 /**
  * Ask use a few questions on command prompt
@@ -346,6 +436,21 @@ function promptUser() {
             when(answers) {
                 return ((answers.source === "guide" && answers.packageJsonExists) || answers.source === "auto");
             }
+        },
+        {
+            type: "confirm",
+            name: "installESLint",
+            message(answers) {
+                const verb = semver.ltr(answers.localESLintVersion, answers.requiredESLintVersionRange)
+                    ? "upgrade"
+                    : "downgrade";
+
+                return `The style guide "${answers.styleguide}" requires eslint@${answers.requiredESLintVersionRange}. You are currently using eslint@${answers.localESLintVersion}.\n  Do you want to ${verb}?`;
+            },
+            default: true,
+            when(answers) {
+                return answers.source === "guide" && answers.packageJsonExists && hasESLintVersionConflict(answers);
+            }
         }
     ]).then(earlyAnswers => {
 
@@ -355,11 +460,14 @@ function promptUser() {
                 log.info("A package.json is necessary to install plugins such as style guides. Run `npm init` to create a package.json file and try again.");
                 return void 0;
             }
+            if (earlyAnswers.installESLint === false && !semver.satisfies(earlyAnswers.localESLintVersion, earlyAnswers.requiredESLintVersionRange)) {
+                log.info(`Note: it might not work since ESLint's version is mismatched with the ${earlyAnswers.styleguide} config.`);
+            }
             if (earlyAnswers.styleguide === "airbnb" && !earlyAnswers.airbnbReact) {
                 earlyAnswers.styleguide = "airbnb-base";
             }
 
-            config = getConfigForStyleGuide(earlyAnswers.styleguide);
+            config = getConfigForStyleGuide(earlyAnswers.styleguide, earlyAnswers.installESLint);
             writeFile(config, earlyAnswers.format);
 
             return void 0;
@@ -479,6 +587,7 @@ function promptUser() {
 
 const init = {
     getConfigForStyleGuide,
+    hasESLintVersionConflict,
     processAnswers,
     /* istanbul ignore next */initializeConfig() {
         return promptUser();

tools/eslint/lib/config/plugins.js

@@ -156,8 +156,20 @@ class Plugins {
      * @param {string[]} pluginNames An array of plugins names.
      * @returns {void}
      * @throws {Error} If a plugin cannot be loaded.
+     * @throws {Error} If "plugins" in config is not an array
      */
     loadAll(pluginNames) {
+
+        // if "plugins" in config is not an array, throw an error so user can fix their config.
+        if (!Array.isArray(pluginNames)) {
+            const pluginNotArrayMessage = "ESLint configuration error: \"plugins\" value must be an array";
+
+            debug(`${pluginNotArrayMessage}: ${JSON.stringify(pluginNames)}`);
+
+            throw new Error(pluginNotArrayMessage);
+        }
+
+        // load each plugin by name
         pluginNames.forEach(this.load, this);
     }
 }