paths in .gitignore are ignored by default

options-manager.js

@@ -7,6 +7,8 @@ const deepAssign = require('deep-assign');
 const multimatch = require('multimatch');
 const resolveFrom = require('resolve-from');
 const pathExists = require('path-exists');
+const globby = require('globby');
+const gitignore = require('parse-gitignore');
 
 const DEFAULT_IGNORE = [
 	'**/node_modules/**',
@@ -195,6 +197,13 @@ function preprocess(opts) {
 	opts = mergeWithPkgConf(opts);
 	opts = normalizeOpts(opts);
 	opts.ignores = DEFAULT_IGNORE.concat(opts.ignores || []);
+
+	// append .gitignore contents if present
+	const paths = globby.sync('.gitignore', {});
+	if (paths.length === 1) {
+		opts.ignores = opts.ignores.concat(gitignore(paths[0]));
+	}
+
 	return opts;
 }
 

package.json

@@ -77,6 +77,7 @@
     "has-flag": "^2.0.0",
     "meow": "^3.4.2",
     "multimatch": "^2.1.0",
+    "parse-gitignore": "^0.3.1",
     "path-exists": "^3.0.0",
     "pkg-conf": "^1.0.1",
     "resolve-cwd": "^1.0.0",

readme.md

@@ -159,7 +159,7 @@ Additional global variables your code accesses during execution.
 
 Type: `Array`
 
-Some [paths](https://github.com/sindresorhus/xo/blob/master/options-manager.js) are ignored by default. Additional ignores can be added here.
+Some [paths](https://github.com/sindresorhus/xo/blob/master/options-manager.js) are ignored by default. Paths in `.gitignore` are also ignored by default. Additional ignores can be added here.
 
 ### space
 

test/cli.js

@@ -31,6 +31,16 @@ test.failing('ignores fixture', async t => {
 	t.throws(execa('../../../cli.js', ['--no-local'], {cwd}));
 });
 
+test('gitignore fixture', async t => {
+	const cwd = path.join(__dirname, 'fixtures/gitignore');
+	try {
+		await execa('../../../cli.js', ['--no-local'], {cwd});
+	} catch (err) {
+		t.is(err.stdout.indexOf('foo.js'), -1);
+		t.true(err.stdout.indexOf('bar.js') !== -1);
+	}
+});
+
 test('supports being extended with a shareable config', async () => {
 	const cwd = path.join(__dirname, 'fixtures/project');
 	await execa('../../../cli.js', ['--no-local'], {cwd});

test/fixtures/gitignore/.gitignore

@@ -0,0 +1 @@
+test/foo.js

test/fixtures/gitignore/index.js

@@ -0,0 +1,5 @@
+'use strict'
+
+module.exports = function (foo) {
+  return foo + 'bar'
+}

test/fixtures/gitignore/package.json

@@ -0,0 +1,21 @@
+{
+  "xo": {
+    "space": 2,
+    "semicolon": false,
+    "overrides": [
+      {
+        "files": "test/*.js",
+        "esnext": true,
+        "space": 3
+      },
+      {
+        "files": "test/foo.js",
+        "space": 4
+      }
+    ],
+    "rules": {
+      "import/no-extraneous-dependencies": 0,
+      "ava/no-ignored-test-files": 0
+    }
+  }
+}

test/fixtures/gitignore/test/bar.js

@@ -0,0 +1,6 @@
+import test from 'ava'
+import fn from '../'
+
+test(t => {
+   t.is(fn('foo'), fn('foobar'))
+})