.github/workflows/main.yml

@@ -0,0 +1,26 @@
+name: CI
+on:
+  - push
+  - pull_request
+jobs:
+  test:
+    name: Node.js ${{ matrix.node-version }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version:
+          - 16
+          - 14
+          - 12
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v2
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm install
+      - run: npm test
+      - uses: codecov/codecov-action@v1
+        if: matrix.node-version == 14
+        with:
+          fail_ci_if_error: true

cli-main.js

@@ -1,19 +1,17 @@
 #!/usr/bin/env node
 'use strict';
-const updateNotifier = require('update-notifier');
 const getStdin = require('get-stdin');
 const meow = require('meow');
 const formatterPretty = require('eslint-formatter-pretty');
 const semver = require('semver');
-const openReport = require('./lib/open-report');
-const xo = require('.');
+const openReport = require('./lib/open-report.js');
+const xo = require('./index.js');
 
 const cli = meow(`
 	Usage
 	  $ xo [<file|glob> ...]
 
 	Options
-	  --init            Add XO to your project
 	  --fix             Automagically fix issues
 	  --reporter        Reporter to use
 	  --env             Environment preset  [Can be set multiple times]
@@ -28,44 +26,46 @@ const cli = meow(`
 	  --open            Open files with issues in your editor
 	  --quiet           Show only errors and no warnings
 	  --extension       Additional extension to lint [Can be set multiple times]
-	  --no-esnext       Don't enforce ES2015+ rules
 	  --cwd=<dir>       Working directory for files
 	  --stdin           Validate/fix code from stdin
 	  --stdin-filename  Specify a filename for the --stdin option
+	  --print-config    Print the effective ESLint config for the given file
 
 	Examples
 	  $ xo
 	  $ xo index.js
 	  $ xo *.js !foo.js
 	  $ xo --space
 	  $ xo --env=node --env=mocha
-	  $ xo --init --space
 	  $ xo --plugin=react
 	  $ xo --plugin=html --extension=html
 	  $ echo 'const x=true' | xo --stdin --fix
+	  $ xo --print-config=index.js
 
 	Tips
-	  Put options in package.json instead of using flags so other tools can read it.
+	  - Add XO to your project with \`npm init xo\`.
+	  - Put options in package.json instead of using flags so other tools can read it.
 `, {
+	autoVersion: false,
 	booleanDefault: undefined,
 	flags: {
-		init: {
-			type: 'boolean'
-		},
 		fix: {
 			type: 'boolean'
 		},
 		reporter: {
 			type: 'string'
 		},
 		env: {
-			type: 'string'
+			type: 'string',
+			isMultiple: true
 		},
 		global: {
-			type: 'string'
+			type: 'string',
+			isMultiple: true
 		},
 		ignore: {
-			type: 'string'
+			type: 'string',
+			isMultiple: true
 		},
 		space: {
 			type: 'string'
@@ -80,10 +80,12 @@ const cli = meow(`
 			type: 'string'
 		},
 		plugin: {
-			type: 'string'
+			type: 'string',
+			isMultiple: true
 		},
 		extend: {
-			type: 'string'
+			type: 'string',
+			isMultiple: true
 		},
 		open: {
 			type: 'boolean'
@@ -92,33 +94,40 @@ const cli = meow(`
 			type: 'boolean'
 		},
 		extension: {
-			type: 'string'
-		},
-		esnext: {
-			type: 'boolean'
+			type: 'string',
+			isMultiple: true
 		},
 		cwd: {
 			type: 'string'
 		},
+		printConfig: {
+			type: 'string'
+		},
 		stdin: {
 			type: 'boolean'
 		},
 		stdinFilename: {
-			type: 'string',
-			alias: 'filename'
+			type: 'string'
 		}
 	}
 });
 
-updateNotifier({pkg: cli.pkg}).notify();
+const {input, flags: options, showVersion} = cli;
 
-const {input, flags: options} = cli;
+// TODO: Fix this properly instead of the below workaround.
+// Revert behavior of meow >8 to pre-8 (7.1.1) for flags using `isMultiple: true`.
+// Otherwise, options defined in package.json can't be merged by lib/options-manager.js `mergeOptions()`.
+for (const key in options) {
+	if (Array.isArray(options[key]) && options[key].length === 0) {
+		delete options[key];
+	}
+}
 
 // Make data types for `options.space` match those of the API
 // Check for string type because `xo --no-space` sets `options.space` to `false`
 if (typeof options.space === 'string') {
 	if (/^\d+$/u.test(options.space)) {
-		options.space = parseInt(options.space, 10);
+		options.space = Number.parseInt(options.space, 10);
 	} else if (options.space === 'true') {
 		options.space = true;
 	} else if (options.space === 'false') {
@@ -133,10 +142,14 @@ if (typeof options.space === 'string') {
 	}
 }
 
-const log = report => {
-	const reporter = options.reporter ? xo.getFormatter(options.reporter) : formatterPretty;
+if (process.env.GITHUB_ACTIONS && !options.fix && !options.reporter) {
+	options.quiet = true;
+}
+
+const log = async report => {
+	const reporter = options.reporter || process.env.GITHUB_ACTIONS ? await xo.getFormatter(options.reporter || 'compact') : formatterPretty;
 	process.stdout.write(reporter(report.results));
-	process.exit(report.errorCount === 0 ? 0 : 1);
+	process.exitCode = report.errorCount === 0 ? 0 : 1;
 };
 
 // `xo -` => `xo --stdin`
@@ -145,41 +158,65 @@ if (input[0] === '-') {
 	input.shift();
 }
 
+if (options.version) {
+	showVersion();
+}
+
 if (options.nodeVersion) {
 	if (options.nodeVersion === 'false') {
 		options.nodeVersion = false;
 	} else if (!semver.validRange(options.nodeVersion)) {
-		console.error('The `node-engine` option must be a valid semver range (for example `>=6`)');
+		console.error('The `--node-engine` flag must be a valid semver range (for example `>=6`)');
 		process.exit(1);
 	}
 }
 
-if (options.init) {
-	require('xo-init')();
-} else if (options.stdin) {
-	getStdin().then(stdin => {
+(async () => {
+	if (options.printConfig) {
+		if (input.length > 0) {
+			console.error('The `--print-config` flag must be used with exactly one filename');
+			process.exit(1);
+		}
+
+		if (options.stdin) {
+			console.error('The `--print-config` flag is not supported on stdin');
+			process.exit(1);
+		}
+
+		options.filePath = options.printConfig;
+		const config = await xo.getConfig(options);
+		console.log(JSON.stringify(config, undefined, '\t'));
+	} else if (options.stdin) {
+		const stdin = await getStdin();
+
+		if (options.stdinFilename) {
+			options.filePath = options.stdinFilename;
+		}
+
 		if (options.fix) {
-			console.log(xo.lintText(stdin, options).results[0].output);
+			const {results: [result]} = await xo.lintText(stdin, options);
+			// If there is no output, pass the stdin back out
+			process.stdout.write((result && result.output) || stdin);
 			return;
 		}
 
 		if (options.open) {
-			console.error('The `open` option is not supported on stdin');
+			console.error('The `--open` flag is not supported on stdin');
 			process.exit(1);
 		}
 
-		log(xo.lintText(stdin, options));
-	});
-} else {
-	xo.lintFiles(input, options).then(report => {
+		await log(await xo.lintText(stdin, options));
+	} else {
+		const report = await xo.lintFiles(input, options);
+
 		if (options.fix) {
-			xo.outputFixes(report);
+			await xo.outputFixes(report);
 		}
 
 		if (options.open) {
 			openReport(report);
 		}
 
-		log(report);
-	});
-}
+		await log(report);
+	}
+})();

cli.js

@@ -1,5 +1,4 @@
 #!/usr/bin/env node
-/* eslint-disable import/no-unassigned-import */
 'use strict';
 const resolveCwd = require('resolve-cwd');
 const hasFlag = require('has-flag');