Upgrade to ESLint 8 and require Node.js 12

.github/workflows/main.yml

@@ -10,9 +10,9 @@ jobs:
       fail-fast: false
       matrix:
         node-version:
+          - 16
           - 14
           - 12
-          - 10
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1

gruntfile.js

@@ -3,7 +3,7 @@ module.exports = grunt => {
 	grunt.initConfig({
 		eslint: {
 			options: {
-				configFile: 'conf/eslint.json',
+				overrideConfigFile: 'conf/eslint.json',
 				rulePaths: ['conf/rules'],
 				quiet: true
 			},

package.json

@@ -11,7 +11,7 @@
 		"url": "https://sindresorhus.com"
 	},
 	"engines": {
-		"node": ">=10"
+		"node": ">=12"
 	},
 	"scripts": {
 		"test": "grunt"
@@ -28,7 +28,7 @@
 	],
 	"dependencies": {
 		"chalk": "^4.0.0",
-		"eslint": "^7.0.0"
+		"eslint": "^8.0.0"
 	},
 	"devDependencies": {
 		"grunt": "^1.0.1",

readme.md

@@ -32,7 +32,7 @@ grunt.registerTask('default', ['eslint']);
 grunt.initConfig({
 	eslint: {
 		options: {
-			configFile: 'conf/eslint.json',
+			overrideConfigFile: 'conf/eslint.json',
 			rulePaths: ['conf/rules']
 		},
 		target: ['file.js']
@@ -55,7 +55,7 @@ grunt.initConfig({
 
 ## Options
 
-See the [ESLint options](https://eslint.org/docs/developer-guide/nodejs-api#cliengine).
+See the [ESLint options](https://eslint.org/docs/developer-guide/nodejs-api#-new-eslintoptions).
 
 In addition the following options are supported:
 

tasks/eslint.js

@@ -1,62 +1,67 @@
 'use strict';
 const chalk = require('chalk');
-const eslint = require('eslint');
+const { ESLint } = require('eslint');
 
 module.exports = grunt => {
-	grunt.registerMultiTask('eslint', 'Validate files with ESLint', function () {
-		const options = this.options({
-			outputFile: false,
-			quiet: false,
-			maxWarnings: -1,
-			failOnError: true,
-		});
-
-		if (this.filesSrc.length === 0) {
-			grunt.log.writeln(chalk.magenta('Could not find any files to validate'));
-			return true;
-		}
+	grunt.registerMultiTask('eslint', 'Validate files with ESLint', async function () {
+		const done = this.async();
 
-		const formatter = eslint.CLIEngine.getFormatter(options.format);
+		try {
+			const { format, quiet, maxWarnings, failOnError, outputFile, ...options } = this.options({
+				outputFile: false,
+				quiet: false,
+				maxWarnings: -1,
+				failOnError: true,
+				format: "stylish"
+			});
 
-		if (!formatter) {
-			grunt.warn(`Could not find formatter ${options.format}`);
-			return false;
-		}
+			if (this.filesSrc.length === 0) {
+				grunt.log.writeln(chalk.magenta('Could not find any files to validate'));
+				return true;
+			}
 
-		const engine = new eslint.CLIEngine(options);
+			const engine = new ESLint(options);
 
-		let report;
-		try {
-			report = engine.executeOnFiles(this.filesSrc);
-		} catch (error) {
-			grunt.warn(error);
-			return false;
-		}
+			const formatter = await engine.loadFormatter(format);
 
-		if (options.fix) {
-			eslint.CLIEngine.outputFixes(report);
-		}
+			if (!formatter) {
+				grunt.warn(`Could not find formatter ${format}`);
+				return false;
+			}
 
-		let results = report.results;
+			let results = await engine.lintFiles(this.filesSrc);
 
-		if (options.quiet) {
-			results = eslint.CLIEngine.getErrorResults(results);
-		}
+			if (options.fix) {
+				await ESLint.outputFixes(results);
+			}
 
-		const output = formatter(results);
+			if (quiet) {
+				results = ESLint.getErrorResults(results);
+			}
 
-		if (options.outputFile) {
-			grunt.file.write(options.outputFile, output);
-		} else if (output) {
-			console.log(output);
-		}
+			const output = formatter.format(results);
 
-		const tooManyWarnings = options.maxWarnings >= 0 && report.warningCount > options.maxWarnings;
+			if (outputFile) {
+				grunt.file.write(outputFile, output);
+			} else if (output) {
+				console.log(output);
+			}
 
-		if (report.errorCount === 0 && tooManyWarnings) {
-			grunt.warn(`ESLint found too many warnings (maximum: ${options.maxWarnings})`);
-		}
+			const { warningCount, errorCount } = results.reduce((count, { warningCount, errorCount }) => {
+				count.warningCount += warningCount;
+				count.errorCount += errorCount;
+				return count;
+			}, { warningCount: 0, errorCount: 0 });
 
-		return options.failOnError ? report.errorCount === 0 : 0;
+			const tooManyWarnings = maxWarnings >= 0 && warningCount > maxWarnings;
+
+			if (errorCount === 0 && tooManyWarnings) {
+				grunt.warn(`ESLint found too many warnings (maximum: ${maxWarnings})`);
+			}
+
+			done(failOnError ? errorCount === 0 : 0);
+		} catch (err) {
+			done(err);
+		}
 	});
-};
+};