Throw an error if run on an ignored file

cli-main.js

@@ -1,10 +1,15 @@
 #!/usr/bin/env node
 'use strict';
+const path = require('path');
 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 globby = require('globby');
+const multimatch = require('multimatch');
+const pkgConf = require('pkg-conf');
+const optionsManager = require('./lib/options-manager');
 const openReport = require('./lib/open-report');
 const xo = require('.');
 
@@ -139,6 +144,41 @@ const log = report => {
 	process.exit(report.errorCount === 0 ? 0 : 1);
 };
 
+const checkIfInputFileIsIgnored = () => {
+	let packageJsonIgnores = [];
+	let cliIgnores = [];
+
+	const packageOpts = pkgConf.sync('xo', {skipOnFalse: true});
+	if (packageOpts.ignores !== undefined && Array.isArray(packageOpts.ignores)) {
+		packageJsonIgnores = packageOpts.ignores;
+	}
+
+	if (options.ignore && Array.isArray(options.ignore)) {
+		cliIgnores = options.ignore;
+	} else if (options.ignore) {
+		cliIgnores.push(options.ignore);
+	}
+
+	const allIgnoredDirectories = optionsManager.DEFAULT_IGNORE.concat(
+		packageJsonIgnores,
+		cliIgnores
+	);
+
+	for (const file of input) {
+		const filename = path.relative(process.cwd(), file);
+		const inIgnoredDirectory =
+			multimatch(filename, allIgnoredDirectories).length > 0;
+		const isGitIgnored = globby.gitignore.sync({
+			cwd: process.cwd(),
+			ignore: optionsManager.DEFAULT_IGNORE
+		})(filename);
+		if (inIgnoredDirectory || isGitIgnored) {
+			console.error(`You cannot run xo on an ignored file ${filename}`);
+			process.exit(1);
+		}
+	}
+};
+
 // `xo -` => `xo --stdin`
 if (input[0] === '-') {
 	options.stdin = true;
@@ -171,6 +211,7 @@ if (options.init) {
 		log(xo.lintText(stdin, options));
 	});
 } else {
+	checkIfInputFileIsIgnored();
 	xo.lintFiles(input, options).then(report => {
 		if (options.fix) {
 			xo.outputFixes(report);

test/cli-main.js

@@ -61,9 +61,11 @@ test('ignore files in .gitignore', async t => {
 	t.deepEqual(files, ['index.js', 'test/bar.js']);
 });
 
-test('ignore explicit files when in .gitgnore', async t => {
+test('fail explicit files when in .gitgnore', async t => {
 	const cwd = path.join(__dirname, 'fixtures/gitignore');
-	await t.notThrowsAsync(main(['test/foo.js', '--reporter=json'], {cwd}));
+	const {stderr} = await t.throwsAsync(main(['test/foo.js', '--reporter=json'], {cwd}));
+	const filename = path.normalize('test/foo.js');
+	t.true(stderr.includes(`You cannot run xo on an ignored file ${filename}`));
 });
 
 test('negative gitignores', async t => {
@@ -150,3 +152,23 @@ test('space option with boolean strings', async t => {
 	t.true(trueResult.stdout.includes('Expected indentation of 2 spaces'));
 	t.true(falseResult.stdout.includes('Expected indentation of 1 tab'));
 });
+
+test('fail explicit files when in ignores array in package.json', async t => {
+	const cwd = path.join(__dirname, 'fixtures/explicit-file-ignores');
+	const {stderr} = await t.throwsAsync(main(['tests/bar.js', '--reporter=json'], {cwd}));
+	const filename = path.normalize('tests/bar.js');
+	t.true(stderr.includes(`You cannot run xo on an ignored file ${filename}`));
+});
+
+test('fail explicit files when in default ignores', async t => {
+	const cwd = path.join(__dirname, 'fixtures/explicit-file-ignores');
+	const {stderr} = await t.throwsAsync(main(['dist/foo.js', '--reporter=json'], {cwd}));
+	const filename = path.normalize('dist/foo.js');
+	t.true(stderr.includes(`You cannot run xo on an ignored file ${filename}`));
+});
+
+test('fail explicit files when in cli ignores', async t => {
+	const cwd = path.join(__dirname, 'fixtures/explicit-file-ignores');
+	const {stderr} = await t.throwsAsync(main(['baz.js', '--ignore', 'baz.js', '--reporter=json'], {cwd}));
+	t.true(stderr.includes('You cannot run xo on an ignored file baz.js'));
+});

test/fixtures/explicit-file-ignores/baz.js

@@ -0,0 +1,2 @@
+const name = "JabClari";
+console.log(name);

test/fixtures/explicit-file-ignores/dist/foo.js

@@ -0,0 +1,2 @@
+const description = "JavaScript happiness style linter ❤️";
+console.log(description);

test/fixtures/explicit-file-ignores/package.json

@@ -0,0 +1,5 @@
+{
+    "xo":{
+        "ignores": ["tests/**"]
+    }
+}

test/fixtures/explicit-file-ignores/tests/bar.js

@@ -0,0 +1,2 @@
+const age = 99;
+console.log(age);