tools: move eslint from tools to tools/node_modules

This is required because we need to add the babel-eslint dependency
and it has to be able to resolve "eslint".
babel-eslint is required to support future ES features such as async
iterators and import.meta.

Refs: https://github.com/nodejs/node/pull/17755
PR-URL: https://github.com/nodejs/node/pull/17820
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

1 files changed, 359 insertions, 0 deletions

diff --git a/tools/node_modules/eslint/lib/config/autoconfig.js b/tools/node_modules/eslint/lib/config/autoconfig.js
new file mode 100644
index 0000000000..8536fdc55a
--- /dev/null
+++ b/tools/node_modules/eslint/lib/config/autoconfig.js
@@ -0,0 +1,359 @@
+/**
+ * @fileoverview Used for creating a suggested configuration based on project code.
+ * @author Ian VanSchooten
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const lodash = require("lodash"),
+    Linter = require("../linter"),
+    configRule = require("./config-rule"),
+    ConfigOps = require("./config-ops"),
+    recConfig = require("../../conf/eslint-recommended");
+
+const debug = require("debug")("eslint:autoconfig");
+const linter = new Linter();
+
+//------------------------------------------------------------------------------
+// Data
+//------------------------------------------------------------------------------
+
+const MAX_CONFIG_COMBINATIONS = 17, // 16 combinations + 1 for severity only
+    RECOMMENDED_CONFIG_NAME = "eslint:recommended";
+
+//------------------------------------------------------------------------------
+// Private
+//------------------------------------------------------------------------------
+
+/**
+ * Information about a rule configuration, in the context of a Registry.
+ *
+ * @typedef {Object}     registryItem
+ * @param   {ruleConfig} config        A valid configuration for the rule
+ * @param   {number}     specificity   The number of elements in the ruleConfig array
+ * @param   {number}     errorCount    The number of errors encountered when linting with the config
+ */
+
+/**
+ * This callback is used to measure execution status in a progress bar
+ * @callback progressCallback
+ * @param {number} The total number of times the callback will be called.
+ */
+
+/**
+ * Create registryItems for rules
+ * @param   {rulesConfig} rulesConfig Hash of rule names and arrays of ruleConfig items
+ * @returns {Object}                  registryItems for each rule in provided rulesConfig
+ */
+function makeRegistryItems(rulesConfig) {
+    return Object.keys(rulesConfig).reduce((accumulator, ruleId) => {
+        accumulator[ruleId] = rulesConfig[ruleId].map(config => ({
+            config,
+            specificity: config.length || 1,
+            errorCount: void 0
+        }));
+        return accumulator;
+    }, {});
+}
+
+/**
+ * Creates an object in which to store rule configs and error counts
+ *
+ * Unless a rulesConfig is provided at construction, the registry will not contain
+ * any rules, only methods.  This will be useful for building up registries manually.
+ *
+ * Registry class
+ */
+class Registry {
+
+    /**
+     * @param {rulesConfig} [rulesConfig] Hash of rule names and arrays of possible configurations
+     */
+    constructor(rulesConfig) {
+        this.rules = (rulesConfig) ? makeRegistryItems(rulesConfig) : {};
+    }
+
+    /**
+     * Populate the registry with core rule configs.
+     *
+     * It will set the registry's `rule` property to an object having rule names
+     * as keys and an array of registryItems as values.
+     *
+     * @returns {void}
+     */
+    populateFromCoreRules() {
+        const rulesConfig = configRule.createCoreRuleConfigs();
+
+        this.rules = makeRegistryItems(rulesConfig);
+    }
+
+    /**
+     * Creates sets of rule configurations which can be used for linting
+     * and initializes registry errors to zero for those configurations (side effect).
+     *
+     * This combines as many rules together as possible, such that the first sets
+     * in the array will have the highest number of rules configured, and later sets
+     * will have fewer and fewer, as not all rules have the same number of possible
+     * configurations.
+     *
+     * The length of the returned array will be <= MAX_CONFIG_COMBINATIONS.
+     *
+     * @param   {Object}   registry The autoconfig registry
+     * @returns {Object[]}          "rules" configurations to use for linting
+     */
+    buildRuleSets() {
+        let idx = 0;
+        const ruleIds = Object.keys(this.rules),
+            ruleSets = [];
+
+        /**
+         * Add a rule configuration from the registry to the ruleSets
+         *
+         * This is broken out into its own function so that it doesn't need to be
+         * created inside of the while loop.
+         *
+         * @param   {string} rule The ruleId to add.
+         * @returns {void}
+         */
+        const addRuleToRuleSet = function(rule) {
+
+            /*
+             * This check ensures that there is a rule configuration and that
+             * it has fewer than the max combinations allowed.
+             * If it has too many configs, we will only use the most basic of
+             * the possible configurations.
+             */
+            const hasFewCombos = (this.rules[rule].length <= MAX_CONFIG_COMBINATIONS);
+
+            if (this.rules[rule][idx] && (hasFewCombos || this.rules[rule][idx].specificity <= 2)) {
+
+                /*
+                 * If the rule has too many possible combinations, only take
+                 * simple ones, avoiding objects.
+                 */
+                if (!hasFewCombos && typeof this.rules[rule][idx].config[1] === "object") {
+                    return;
+                }
+
+                ruleSets[idx] = ruleSets[idx] || {};
+                ruleSets[idx][rule] = this.rules[rule][idx].config;
+
+                /*
+                 * Initialize errorCount to zero, since this is a config which
+                 * will be linted.
+                 */
+                this.rules[rule][idx].errorCount = 0;
+            }
+        }.bind(this);
+
+        while (ruleSets.length === idx) {
+            ruleIds.forEach(addRuleToRuleSet);
+            idx += 1;
+        }
+
+        return ruleSets;
+    }
+
+    /**
+     * Remove all items from the registry with a non-zero number of errors
+     *
+     * Note: this also removes rule configurations which were not linted
+     * (meaning, they have an undefined errorCount).
+     *
+     * @returns {void}
+     */
+    stripFailingConfigs() {
+        const ruleIds = Object.keys(this.rules),
+            newRegistry = new Registry();
+
+        newRegistry.rules = Object.assign({}, this.rules);
+        ruleIds.forEach(ruleId => {
+            const errorFreeItems = newRegistry.rules[ruleId].filter(registryItem => (registryItem.errorCount === 0));
+
+            if (errorFreeItems.length > 0) {
+                newRegistry.rules[ruleId] = errorFreeItems;
+            } else {
+                delete newRegistry.rules[ruleId];
+            }
+        });
+
+        return newRegistry;
+    }
+
+    /**
+     * Removes rule configurations which were not included in a ruleSet
+     *
+     * @returns {void}
+     */
+    stripExtraConfigs() {
+        const ruleIds = Object.keys(this.rules),
+            newRegistry = new Registry();
+
+        newRegistry.rules = Object.assign({}, this.rules);
+        ruleIds.forEach(ruleId => {
+            newRegistry.rules[ruleId] = newRegistry.rules[ruleId].filter(registryItem => (typeof registryItem.errorCount !== "undefined"));
+        });
+
+        return newRegistry;
+    }
+
+    /**
+     * Creates a registry of rules which had no error-free configs.
+     * The new registry is intended to be analyzed to determine whether its rules
+     * should be disabled or set to warning.
+     *
+     * @returns {Registry}  A registry of failing rules.
+     */
+    getFailingRulesRegistry() {
+        const ruleIds = Object.keys(this.rules),
+            failingRegistry = new Registry();
+
+        ruleIds.forEach(ruleId => {
+            const failingConfigs = this.rules[ruleId].filter(registryItem => (registryItem.errorCount > 0));
+
+            if (failingConfigs && failingConfigs.length === this.rules[ruleId].length) {
+                failingRegistry.rules[ruleId] = failingConfigs;
+            }
+        });
+
+        return failingRegistry;
+    }
+
+    /**
+     * Create an eslint config for any rules which only have one configuration
+     * in the registry.
+     *
+     * @returns {Object} An eslint config with rules section populated
+     */
+    createConfig() {
+        const ruleIds = Object.keys(this.rules),
+            config = { rules: {} };
+
+        ruleIds.forEach(ruleId => {
+            if (this.rules[ruleId].length === 1) {
+                config.rules[ruleId] = this.rules[ruleId][0].config;
+            }
+        });
+
+        return config;
+    }
+
+    /**
+     * Return a cloned registry containing only configs with a desired specificity
+     *
+     * @param   {number} specificity Only keep configs with this specificity
+     * @returns {Registry}           A registry of rules
+     */
+    filterBySpecificity(specificity) {
+        const ruleIds = Object.keys(this.rules),
+            newRegistry = new Registry();
+
+        newRegistry.rules = Object.assign({}, this.rules);
+        ruleIds.forEach(ruleId => {
+            newRegistry.rules[ruleId] = this.rules[ruleId].filter(registryItem => (registryItem.specificity === specificity));
+        });
+
+        return newRegistry;
+    }
+
+    /**
+     * Lint SourceCodes against all configurations in the registry, and record results
+     *
+     * @param   {Object[]} sourceCodes  SourceCode objects for each filename
+     * @param   {Object}   config       ESLint config object
+     * @param   {progressCallback} [cb] Optional callback for reporting execution status
+     * @returns {Registry}              New registry with errorCount populated
+     */
+    lintSourceCode(sourceCodes, config, cb) {
+        let lintedRegistry = new Registry();
+
+        lintedRegistry.rules = Object.assign({}, this.rules);
+
+        const ruleSets = lintedRegistry.buildRuleSets();
+
+        lintedRegistry = lintedRegistry.stripExtraConfigs();
+
+        debug("Linting with all possible rule combinations");
+
+        const filenames = Object.keys(sourceCodes);
+        const totalFilesLinting = filenames.length * ruleSets.length;
+
+        filenames.forEach(filename => {
+            debug(`Linting file: ${filename}`);
+
+            let ruleSetIdx = 0;
+
+            ruleSets.forEach(ruleSet => {
+                const lintConfig = Object.assign({}, config, { rules: ruleSet });
+                const lintResults = linter.verify(sourceCodes[filename], lintConfig);
+
+                lintResults.forEach(result => {
+
+                    /*
+                     * It is possible that the error is from a configuration comment
+                     * in a linted file, in which case there may not be a config
+                     * set in this ruleSetIdx.
+                     * (https://github.com/eslint/eslint/issues/5992)
+                     * (https://github.com/eslint/eslint/issues/7860)
+                     */
+                    if (
+                        lintedRegistry.rules[result.ruleId] &&
+                        lintedRegistry.rules[result.ruleId][ruleSetIdx]
+                    ) {
+                        lintedRegistry.rules[result.ruleId][ruleSetIdx].errorCount += 1;
+                    }
+                });
+
+                ruleSetIdx += 1;
+
+                if (cb) {
+                    cb(totalFilesLinting); // eslint-disable-line callback-return
+                }
+            });
+
+            // Deallocate for GC
+            sourceCodes[filename] = null;
+        });
+
+        return lintedRegistry;
+    }
+}
+
+/**
+ * Extract rule configuration into eslint:recommended where possible.
+ *
+ * This will return a new config with `"extends": "eslint:recommended"` and
+ * only the rules which have configurations different from the recommended config.
+ *
+ * @param   {Object} config config object
+ * @returns {Object}        config object using `"extends": "eslint:recommended"`
+ */
+function extendFromRecommended(config) {
+    const newConfig = Object.assign({}, config);
+
+    ConfigOps.normalizeToStrings(newConfig);
+
+    const recRules = Object.keys(recConfig.rules).filter(ruleId => ConfigOps.isErrorSeverity(recConfig.rules[ruleId]));
+
+    recRules.forEach(ruleId => {
+        if (lodash.isEqual(recConfig.rules[ruleId], newConfig.rules[ruleId])) {
+            delete newConfig.rules[ruleId];
+        }
+    });
+    newConfig.extends = RECOMMENDED_CONFIG_NAME;
+    return newConfig;
+}
+
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+module.exports = {
+    Registry,
+    extendFromRecommended
+};