refactor: Use eslint-config-eslint for linting this repo (#43)

Author: mdjermanovic

eslint.config.js

@@ -1,12 +1,45 @@
-import js from "@eslint/js";
+import eslintConfigESLint from "eslint-config-eslint";
+
+const eslintPluginJSDoc = eslintConfigESLint.find(
+	config => config.plugins?.jsdoc,
+).plugins.jsdoc;
 
 export default [
-	js.configs.recommended,
 	{
-		ignores: ["**/tests/fixtures/**/*.*"],
+		ignores: ["**/tests/fixtures/", "**/dist/"],
+	},
+
+	...eslintConfigESLint,
+
+	{
+		rules: {
+			// disable rules we don't want to use from eslint-config-eslint
+			"no-undefined": "off",
+
+			// TODO: re-enable eslint-plugin-jsdoc rules
+			...Object.fromEntries(
+				Object.keys(eslintPluginJSDoc.rules).map(name => [
+					`jsdoc/${name}`,
+					"off",
+				]),
+			),
+		},
+	},
+
+	// Tools and CLI
+	{
+		files: [
+			"scripts/**",
+			"packages/migrate-config/src/migrate-config-cli.js",
+		],
+		rules: {
+			"no-console": "off",
+			"n/no-process-exit": "off",
+		},
 	},
+
 	{
-		files: ["**/*.test.js"],
+		files: ["**/tests/**"],
 		languageOptions: {
 			globals: {
 				describe: "readonly",

package.json

@@ -26,9 +26,8 @@
     "!(*.js)": "prettier --write --ignore-unknown"
   },
   "devDependencies": {
-    "@eslint/js": "^9.0.0",
-    "eslint": "^9.0.0",
-    "eslint-config-eslint": "^10.0.0",
+    "eslint": "^9.4.0",
+    "eslint-config-eslint": "^11.0.0",
     "lint-staged": "^15.2.0",
     "prettier": "^3.1.1",
     "yorkie": "^2.0.0"

packages/compat/src/fixup-rules.js

@@ -1,9 +1,7 @@
 /**
- * @filedescription Object Schema
+ * @fileoverview Object Schema
  */
 
-"use strict";
-
 //-----------------------------------------------------------------------------
 // Imports
 //-----------------------------------------------------------------------------
@@ -102,7 +100,7 @@ export function fixupRule(ruleDefinition) {
 		? ruleDefinition
 		: ruleDefinition.create.bind(ruleDefinition);
 
-	const ruleCreate = context => {
+	function ruleCreate(context) {
 		// if getScope is already there then no need to create old methods
 		if ("getScope" in context) {
 			return originalCreate(context);
@@ -161,6 +159,7 @@ export function fixupRule(ruleDefinition) {
 			 * and the third argument for onCodePathSegmentLoop.
 			 */
 			if (methodName.startsWith("on")) {
+				// eslint-disable-next-line no-loop-func -- intentionally updating shared `currentNode` variable
 				visitor[methodName] = (...args) => {
 					currentNode =
 						args[methodName === "onCodePathSegmentLoop" ? 2 : 1];
@@ -171,6 +170,7 @@ export function fixupRule(ruleDefinition) {
 				continue;
 			}
 
+			// eslint-disable-next-line no-loop-func -- intentionally updating shared `currentNode` variable
 			visitor[methodName] = (...args) => {
 				currentNode = args[0];
 
@@ -179,7 +179,7 @@ export function fixupRule(ruleDefinition) {
 		}
 
 		return visitor;
-	};
+	}
 
 	const newRuleDefinition = {
 		...(isLegacyRule ? undefined : ruleDefinition),
@@ -239,20 +239,20 @@ export function fixupPluginRules(plugin) {
 export function fixupConfigRules(config) {
 	const configs = Array.isArray(config) ? config : [config];
 
-	return configs.map(config => {
-		if (!config.plugins) {
-			return config;
+	return configs.map(configItem => {
+		if (!configItem.plugins) {
+			return configItem;
 		}
 
 		const newPlugins = Object.fromEntries(
-			Object.entries(config.plugins).map(([pluginName, plugin]) => [
+			Object.entries(configItem.plugins).map(([pluginName, plugin]) => [
 				pluginName,
 				fixupPluginRules(plugin),
 			]),
 		);
 
 		return {
-			...config,
+			...configItem,
 			plugins: newPlugins,
 		};
 	});

packages/compat/src/index.js

@@ -1,5 +1,5 @@
 /**
- * @filedescription Object Schema Package
+ * @fileoverview Object Schema Package
  */
 
 export * from "./fixup-rules.js";

packages/compat/tests/fixup-rules.js

@@ -1,7 +1,6 @@
 /**
- * @filedescription Fixup tests
+ * @fileoverview Fixup tests
  */
-/* global it, describe */
 
 //-----------------------------------------------------------------------------
 // Imports

packages/compat/tests/rules/prefer-rest-params.js

@@ -3,8 +3,6 @@
  * @author Toru Nagashima
  */
 
-"use strict";
-
 //------------------------------------------------------------------------------
 // Requirements
 //------------------------------------------------------------------------------

packages/compat/tests/rules/require-atomic-updates.js

@@ -2,7 +2,6 @@
  * @fileoverview disallow assignments that can lead to race conditions due to usage of `await` or `yield`
  * @author Teddy Katz
  */
-"use strict";
 
 //------------------------------------------------------------------------------
 // Requirements

packages/config-array/src/config-array.js

@@ -425,7 +425,7 @@ function pathMatches(filePath, basePath, config) {
 	const relativeFilePath = path.relative(basePath, filePath);
 
 	// match both strings and functions
-	const match = pattern => {
+	function match(pattern) {
 		if (isString(pattern)) {
 			return doMatch(relativeFilePath, pattern);
 		}
@@ -435,7 +435,7 @@ function pathMatches(filePath, basePath, config) {
 		}
 
 		throw new TypeError(`Unexpected matcher type ${pattern}.`);
-	};
+	}
 
 	// check for all matches to config.files
 	let filePathMatchesPattern = config.files.some(pattern => {
@@ -756,6 +756,8 @@ export class ConfigArray extends Array {
 		return this;
 	}
 
+	/* eslint-disable class-methods-use-this -- Desired as instance methods */
+
 	/**
 	 * Finalizes the state of a config before being cached and returned by
 	 * `getConfig()`. Does nothing by default but is provided to be
@@ -779,6 +781,8 @@ export class ConfigArray extends Array {
 		return config;
 	}
 
+	/* eslint-enable class-methods-use-this -- Desired as instance methods */
+
 	/**
 	 * Determines if a given file path explicitly matches a `files` entry
 	 * and also doesn't match an `ignores` entry. Configs that don't have
@@ -793,9 +797,9 @@ export class ConfigArray extends Array {
 		const cache = dataCache.get(this);
 
 		// first check the cache to avoid duplicate work
-		let result = cache.explicitMatches.get(filePath);
+		const result = cache.explicitMatches.get(filePath);
 
-		if (typeof result == "boolean") {
+		if (typeof result === "boolean") {
 			return result;
 		}
 
@@ -880,7 +884,7 @@ export class ConfigArray extends Array {
 
 		const matchingConfigIndices = [];
 		let matchFound = false;
-		const universalPattern = /\/\*{1,2}$/;
+		const universalPattern = /\/\*{1,2}$/u;
 
 		this.forEach((config, index) => {
 			if (!config.files) {
@@ -959,7 +963,6 @@ export class ConfigArray extends Array {
 				debug(`Matching config found for ${filePath}`);
 				matchingConfigIndices.push(index);
 				matchFound = true;
-				return;
 			}
 		});
 
@@ -985,6 +988,7 @@ export class ConfigArray extends Array {
 
 		// otherwise construct the config
 
+		// eslint-disable-next-line array-callback-return, consistent-return -- rethrowConfigError always throws an error
 		let finalConfig = matchingConfigIndices.reduce((result, index) => {
 			try {
 				return this[ConfigArraySymbol.schema].merge(
@@ -1065,7 +1069,7 @@ export class ConfigArray extends Array {
 
 		const relativeDirectoryPath = path
 			.relative(this.basePath, directoryPath)
-			.replace(/\\/g, "/");
+			.replace(/\\/gu, "/");
 
 		if (relativeDirectoryPath.startsWith("..")) {
 			return true;
@@ -1080,7 +1084,7 @@ export class ConfigArray extends Array {
 
 		const directoryParts = relativeDirectoryPath.split("/");
 		let relativeDirectoryToCheck = "";
-		let result = false;
+		let result;
 
 		/*
 		 * In order to get the correct gitignore-style ignores, where an
@@ -1092,7 +1096,7 @@ export class ConfigArray extends Array {
 		 * have to recalculate everything for every call.
 		 */
 		do {
-			relativeDirectoryToCheck += directoryParts.shift() + "/";
+			relativeDirectoryToCheck += `${directoryParts.shift()}/`;
 
 			result = shouldIgnorePath(
 				this.ignores,