Breaking: improve plugin resolving (refs eslint/rfcs#47)

docs/user-guide/configuring.md

@@ -968,6 +968,8 @@ project-root
 
 The config in `app/.eslintrc.json` defines the glob pattern `**/*Spec.js`. This pattern is relative to the base directory of `app/.eslintrc.json`. So, this pattern would match `app/lib/fooSpec.js` and `app/components/barSpec.js` but **NOT** `server/serverSpec.js`. If you defined the same pattern in the `.eslintrc.json` file within in the `project-root` folder, it would match all three of the `*Spec` files.
 
+If `--config` option provides a config, the glob patterns in the config are relative to the current working directory rather than the base directory of the given config. For example, if `--config configs/.eslintrc.json` is present, the glob patterns in the config are relative to `.` rather than `./configs`.
+
 ### Example configuration
 
 In your `.eslintrc.json`:
@@ -1032,6 +1034,10 @@ You can tell ESLint to ignore specific files and directories by `ignorePatterns`
 * You cannot write `ignorePatterns` property under `overrides` property.
 * `.eslintignore` can override `ignorePatterns` property of config files.
 
+If a glob pattern starts with `/`, the pattern is relative to the base directory of the config file. For example, `/foo.js` in `lib/.eslintrc.json` matches to `lib/foo.js` but not `lib/subdir/foo.js`.
+
+If `--config` option provides a config, the ignore patterns that start with `/` in the config are relative to the current working directory rather than the base directory of the given config. For example, if `--config configs/.eslintrc.json` is present, the ignore patterns in the config are relative to `.` rather than `./configs`.
+
 ### `.eslintignore`
 
 You can tell ESLint to ignore specific files and directories by creating an `.eslintignore` file in your project's root directory. The `.eslintignore` file is a plain text file where each line is a glob pattern indicating which paths should be omitted from linting. For example, the following will omit all JavaScript files:
@@ -1045,7 +1051,7 @@ When ESLint is run, it looks in the current working directory to find an `.eslin
 Globs are matched using [node-ignore](https://github.com/kaelzhang/node-ignore), so a number of features are available:
 
 * Lines beginning with `#` are treated as comments and do not affect ignore patterns.
-* Paths are relative to `.eslintignore` location or the current working directory. This is also true of paths passed in via the `--ignore-pattern` [command](./command-line-interface.md#--ignore-pattern).
+* Paths are relative to the current working directory. This is also true of paths passed in via the `--ignore-pattern` [command](./command-line-interface.md#--ignore-pattern).
 * Lines preceded by `!` are negated patterns that re-include a pattern that was ignored by an earlier pattern.
 * Ignore patterns behave according to the `.gitignore` [specification](https://git-scm.com/docs/gitignore).
 

lib/cli-engine/cascading-config-array-factory.js

@@ -140,6 +140,7 @@ function createBaseConfigArray({
 function createCLIConfigArray({
     cliConfigData,
     configArrayFactory,
+    cwd,
     ignorePath,
     specificConfigPath
 }) {
@@ -158,7 +159,7 @@ function createCLIConfigArray({
         cliConfigArray.unshift(
             ...configArrayFactory.loadFile(
                 specificConfigPath,
-                { name: "--config" }
+                { name: "--config", basePath: cwd }
             )
         );
     }
@@ -198,7 +199,7 @@ class CascadingConfigArrayFactory {
         cliConfig: cliConfigData = null,
         cwd = process.cwd(),
         ignorePath,
-        resolvePluginsRelativeTo = cwd,
+        resolvePluginsRelativeTo,
         rulePaths = [],
         specificConfigPath = null,
         useEslintrc = true
@@ -220,6 +221,7 @@ class CascadingConfigArrayFactory {
             cliConfigArray: createCLIConfigArray({
                 cliConfigData,
                 configArrayFactory,
+                cwd,
                 ignorePath,
                 specificConfigPath
             }),

lib/cli-engine/cli-engine.js

@@ -20,12 +20,13 @@ const path = require("path");
 const defaultOptions = require("../../conf/default-cli-options");
 const pkg = require("../../package.json");
 const ConfigOps = require("../shared/config-ops");
+const { emitDeprecationWarning } = require("../shared/deprecation-warnings");
 const naming = require("../shared/naming");
 const ModuleResolver = require("../shared/relative-module-resolver");
 const { Linter } = require("../linter");
 const builtInRules = require("../rules");
 const { CascadingConfigArrayFactory } = require("./cascading-config-array-factory");
-const { IgnorePattern, getUsedExtractedConfigs } = require("./config-array");
+const { IgnorePattern } = require("./config-array");
 const { FileEnumerator } = require("./file-enumerator");
 const hash = require("./hash");
 const LintResultCache = require("./lint-result-cache");
@@ -75,6 +76,13 @@ const validFixTypes = new Set(["problem", "suggestion", "layout"]);
  * @property {string} resolvePluginsRelativeTo The folder where plugins should be resolved from, defaulting to the CWD
  */
 
+/**
+ * Information of deprecated rules.
+ * @typedef {Object} DeprecatedRuleInfo
+ * @property {string} ruleId The rule ID.
+ * @property {string[]} replacedBy The rule IDs that replace this deprecated rule.
+ */
+
 /**
  * A linting result.
  * @typedef {Object} LintResult
@@ -86,13 +94,7 @@ const validFixTypes = new Set(["problem", "suggestion", "layout"]);
  * @property {number} fixableWarningCount Number of fixable warnings for the result.
  * @property {string} [source] The source code of the file that was linted.
  * @property {string} [output] The source code of the file that was linted, with as many fixes applied as possible.
- */
-
-/**
- * Information of deprecated rules.
- * @typedef {Object} DeprecatedRuleInfo
- * @property {string} ruleId The rule ID.
- * @property {string[]} replacedBy The rule IDs that replace this deprecated rule.
+ * @property {DeprecatedRuleInfo[]} usedDeprecatedRules The list of used deprecated rules.
  */
 
 /**
@@ -103,7 +105,6 @@ const validFixTypes = new Set(["problem", "suggestion", "layout"]);
  * @property {number} warningCount Number of warnings for the result.
  * @property {number} fixableErrorCount Number of fixable errors for the result.
  * @property {number} fixableWarningCount Number of fixable warnings for the result.
- * @property {DeprecatedRuleInfo[]} usedDeprecatedRules The list of used deprecated rules.
  */
 
 /**
@@ -191,6 +192,59 @@ function calculateStatsPerRun(results) {
     });
 }
 
+/**
+ * Collect used deprecated rules.
+ * @param {ExtractedConfig} config The config which were used.
+ * @param {Map<string, Rule>} pluginRules The rule definitions of loaded plugins.
+ * @returns {DeprecatedRuleInfo[]} Used deprecated rules.
+ */
+function getRuleDeprecationWarnings(config, pluginRules) {
+    const retv = [];
+
+    for (const [ruleId, ruleConfig] of Object.entries(config.rules)) {
+
+        // Skip if it's not used.
+        if (!ConfigOps.getRuleSeverity(ruleConfig)) {
+            continue;
+        }
+        const rule = pluginRules.get(ruleId) || builtInRules.get(ruleId);
+
+        // Skip if it's not deprecated.
+        if (!(rule && rule.meta && rule.meta.deprecated)) {
+            continue;
+        }
+
+        // This rule was used and deprecated.
+        retv.push({
+            ruleId,
+            replacedBy: rule.meta.replacedBy || []
+        });
+    }
+
+    return retv;
+}
+
+/**
+ * Merge used deprecated rules from all lint results.
+ * @param {LintResult[]} results The lint results.
+ * @returns {DeprecatedRuleInfo[]} Used deprecated rules.
+ */
+function mergeRuleDeprecationWarnings(results) {
+    const retv = [];
+    const ids = new Set();
+
+    for (const { usedDeprecatedRules } of results) {
+        for (const usedDeprecatedRule of usedDeprecatedRules) {
+            if (!ids.has(usedDeprecatedRule.ruleId)) {
+                ids.add(usedDeprecatedRule.ruleId);
+                retv.push(usedDeprecatedRule);
+            }
+        }
+    }
+
+    return retv;
+}
+
 /**
  * Processes an source code using ESLint.
  * @param {Object} config The config object.
@@ -264,6 +318,11 @@ function verifyText({
         result.source = text;
     }
 
+    result.usedDeprecatedRules = getRuleDeprecationWarnings(
+        config.extractConfig(filePathToVerify),
+        config.pluginRules
+    );
+
     return result;
 }
 
@@ -323,50 +382,6 @@ function getRule(ruleId, configArrays) {
     return builtInRules.get(ruleId) || null;
 }
 
-/**
- * Collect used deprecated rules.
- * @param {ConfigArray[]} usedConfigArrays The config arrays which were used.
- * @returns {IterableIterator<DeprecatedRuleInfo>} Used deprecated rules.
- */
-function *iterateRuleDeprecationWarnings(usedConfigArrays) {
-    const processedRuleIds = new Set();
-
-    // Flatten used configs.
-    /** @type {ExtractedConfig[]} */
-    const configs = [].concat(
-        ...usedConfigArrays.map(getUsedExtractedConfigs)
-    );
-
-    // Traverse rule configs.
-    for (const config of configs) {
-        for (const [ruleId, ruleConfig] of Object.entries(config.rules)) {
-
-            // Skip if it was processed.
-            if (processedRuleIds.has(ruleId)) {
-                continue;
-            }
-            processedRuleIds.add(ruleId);
-
-            // Skip if it's not used.
-            if (!ConfigOps.getRuleSeverity(ruleConfig)) {
-                continue;
-            }
-            const rule = getRule(ruleId, usedConfigArrays);
-
-            // Skip if it's not deprecated.
-            if (!(rule && rule.meta && rule.meta.deprecated)) {
-                continue;
-            }
-
-            // This rule was used and deprecated.
-            yield {
-                ruleId,
-                replacedBy: rule.meta.replacedBy || []
-            };
-        }
-    }
-}
-
 /**
  * Checks if the given message is an error message.
  * @param {LintMessage} message The message to check.
@@ -620,7 +635,14 @@ class CLIEngine {
         }
     }
 
+    /**
+     * Get rules that the last `executeOn*` methods used.
+     * @returns {Map<string, Rule>} A map of rule Id and rule implementation.
+     * @deprecated
+     */
     getRules() {
+        emitDeprecationWarning("getRules()", "ESLINT_LEGACY_GET_RULES");
+
         const { lastConfigArrays } = internalSlotsMap.get(this);
 
         return new Map(function *() {
@@ -823,16 +845,15 @@ class CLIEngine {
             lintResultCache.reconcile();
         }
 
-        // Collect used deprecated rules.
-        const usedDeprecatedRules = Array.from(
-            iterateRuleDeprecationWarnings(lastConfigArrays)
-        );
-
         debug(`Linting complete in: ${Date.now() - startTime}ms`);
         return {
             results,
             ...calculateStatsPerRun(results),
-            usedDeprecatedRules
+
+            get usedDeprecatedRules() {
+                emitDeprecationWarning("executeOnFiles()", "ESLINT_LEGACY_USED_DEPRECATED_RULES");
+                return mergeRuleDeprecationWarnings(results);
+            }
         };
     }
 
@@ -894,16 +915,15 @@ class CLIEngine {
             }));
         }
 
-        // Collect used deprecated rules.
-        const usedDeprecatedRules = Array.from(
-            iterateRuleDeprecationWarnings(lastConfigArrays)
-        );
-
         debug(`Linting complete in: ${Date.now() - startTime}ms`);
         return {
             results,
             ...calculateStatsPerRun(results),
-            usedDeprecatedRules
+
+            get usedDeprecatedRules() {
+                emitDeprecationWarning("executeOnText()", "ESLINT_LEGACY_USED_DEPRECATED_RULES");
+                return mergeRuleDeprecationWarnings(results);
+            }
         };
     }
 
@@ -931,6 +951,32 @@ class CLIEngine {
             .toCompatibleObjectAsConfigFileContent();
     }
 
+    /**
+     * Returns rule objects for the given file based on the CLI options.
+     * @param {string} filePath The path of the file to retrieve rules for.
+     * @returns {Map<string, Rule>} A map of rule ID and rule implementation that is used to lint the file.
+     */
+    getRulesForFile(filePath) {
+        const { configArrayFactory, options } = internalSlotsMap.get(this);
+        const absolutePath = path.resolve(options.cwd, filePath);
+
+        if (directoryExists(absolutePath)) {
+            throw Object.assign(
+                new Error("'filePath' should not be a directory path."),
+                { messageTemplate: "print-config-with-directory-path" }
+            );
+        }
+        const configArray = configArrayFactory.getConfigArrayForFile(
+            absolutePath,
+            { ignoreNotFoundError: true }
+        );
+
+        return new Map(function *() {
+            yield* builtInRules;
+            yield* configArray.pluginRules;
+        }());
+    }
+
     /**
      * Checks if a given path is ignored by ESLint.
      * @param {string} filePath The path of the file to check.