From 0e7d1b33f78cce09dedff4f747e2a3aa3e3d6935 Mon Sep 17 00:00:00 2001
From: RyanZim <opensrc@ryanzim.com>
Date: Thu, 13 Apr 2017 19:03:14 -0400
Subject: [PATCH] Add pathExists() and pathExistsSync()

---
 README.md                                     |  2 +
 docs/pathExists-sync.md                       |  3 ++
 docs/pathExists.md                            | 22 ++++++++++
 lib/index.js                                  |  1 +
 .../__tests__/path-exists-sync.test.js        | 28 +++++++++++++
 lib/path-exists/__tests__/path-exists.test.js | 40 +++++++++++++++++++
 lib/path-exists/index.js                      | 12 ++++++
 7 files changed, 108 insertions(+)
 create mode 100644 docs/pathExists-sync.md
 create mode 100644 docs/pathExists.md
 create mode 100644 lib/path-exists/__tests__/path-exists-sync.test.js
 create mode 100644 lib/path-exists/__tests__/path-exists.test.js
 create mode 100644 lib/path-exists/index.js

diff --git a/README.md b/README.md
index 6a114e48..4e6e127e 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,7 @@ Methods
 - [move](docs/move.md)
 - [outputFile](docs/outputFile.md)
 - [outputJson](docs/outputJson.md)
+- [pathExists](docs/pathExists.md)
 - [readJson](docs/readJson.md)
 - [remove](docs/remove.md)
 - [writeJson](docs/writeJson.md)
@@ -123,6 +124,7 @@ Methods
 - [moveSync](docs/move-sync.md)
 - [outputFileSync](docs/outputFile-sync.md)
 - [outputJsonSync](docs/outputJson-sync.md)
+- [pathExistsSync](docs/pathExists-sync.md)
 - [readJsonSync](docs/readJson-sync.md)
 - [removeSync](docs/remove-sync.md)
 - [writeJsonSync](docs/writeJson-sync.md)
diff --git a/docs/pathExists-sync.md b/docs/pathExists-sync.md
new file mode 100644
index 00000000..3ef973c2
--- /dev/null
+++ b/docs/pathExists-sync.md
@@ -0,0 +1,3 @@
+# pathExistsSync(file)
+
+An alias for [`fs.existsSync()`](https://nodejs.org/api/fs.html#fs_fs_existssync_path), created for consistency with [`pathExists()`](pathExists.md).
diff --git a/docs/pathExists.md b/docs/pathExists.md
new file mode 100644
index 00000000..0302b09d
--- /dev/null
+++ b/docs/pathExists.md
@@ -0,0 +1,22 @@
+# pathExists(file[, callback])
+
+Test whether or not the given path exists by checking with the file system. Like [`fs.exists`](https://nodejs.org/api/fs.html#fs_fs_exists_path_callback), but with a normal callback signature (err, exists). Uses `fs.access` under the hood.
+
+- `file` `<String>`
+- `callback` `<Function>`
+
+## Example:
+
+```js
+const fs = require('fs-extra')
+
+const file = '/tmp/this/path/does/not/exist/file.txt'
+// Promise usage:
+fs.pathExists(file)
+  .then(exists => console.log(exists)) // => false
+// Callback usage:
+fs.pathExists(file, (err, exists) => {
+  console.log(err) // => null
+  console.log(exists) // => false
+})
+```
diff --git a/lib/index.js b/lib/index.js
index dd9fe2b2..cb7dd9e6 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -17,5 +17,6 @@ assign(fs, require('./move-sync'))
 assign(fs, require('./empty'))
 assign(fs, require('./ensure'))
 assign(fs, require('./output'))
+assign(fs, require('./path-exists'))
 
 module.exports = fs
diff --git a/lib/path-exists/__tests__/path-exists-sync.test.js b/lib/path-exists/__tests__/path-exists-sync.test.js
new file mode 100644
index 00000000..dbde2b44
--- /dev/null
+++ b/lib/path-exists/__tests__/path-exists-sync.test.js
@@ -0,0 +1,28 @@
+'use strict'
+/* eslint-env mocha */
+
+const fs = require(process.cwd())
+const path = require('path')
+const os = require('os')
+const assert = require('assert')
+
+describe('pathExists()', () => {
+  let TEST_DIR
+
+  beforeEach(done => {
+    TEST_DIR = path.join(os.tmpdir(), 'fs-extra', 'path-exists')
+    fs.emptyDir(TEST_DIR, done)
+  })
+
+  afterEach(done => fs.remove(TEST_DIR, done))
+
+  it('should return false if file does not exist', () => {
+    assert(!fs.pathExistsSync(path.join(TEST_DIR, 'somefile')))
+  })
+
+  it('should return true if file does exist', () => {
+    const file = path.join(TEST_DIR, 'exists')
+    fs.ensureFileSync(file)
+    assert(fs.pathExistsSync(file))
+  })
+})
diff --git a/lib/path-exists/__tests__/path-exists.test.js b/lib/path-exists/__tests__/path-exists.test.js
new file mode 100644
index 00000000..abc1e634
--- /dev/null
+++ b/lib/path-exists/__tests__/path-exists.test.js
@@ -0,0 +1,40 @@
+'use strict'
+/* eslint-env mocha */
+
+const fs = require(process.cwd())
+const path = require('path')
+const os = require('os')
+const assert = require('assert')
+
+describe('pathExists()', () => {
+  let TEST_DIR
+
+  beforeEach(done => {
+    TEST_DIR = path.join(os.tmpdir(), 'fs-extra', 'path-exists')
+    fs.emptyDir(TEST_DIR, done)
+  })
+
+  afterEach(done => fs.remove(TEST_DIR, done))
+
+  it('should return false if file does not exist', () => {
+    return fs.pathExists(path.join(TEST_DIR, 'somefile'))
+      .then(exists => assert(!exists))
+  })
+
+  it('should return true if file does exist', () => {
+    const file = path.join(TEST_DIR, 'exists')
+    fs.ensureFileSync(file)
+    return fs.pathExists(file)
+      .then(exists => assert(exists))
+  })
+
+  it('should pass an empty error parameter to the callback', done => {
+    const file = path.join(TEST_DIR, 'exists')
+    fs.ensureFileSync(file)
+    fs.pathExists(file, (err, exists) => {
+      assert.ifError(err)
+      assert(exists)
+      done()
+    })
+  })
+})
diff --git a/lib/path-exists/index.js b/lib/path-exists/index.js
new file mode 100644
index 00000000..ddd9bc71
--- /dev/null
+++ b/lib/path-exists/index.js
@@ -0,0 +1,12 @@
+'use strict'
+const u = require('universalify').fromPromise
+const fs = require('../fs')
+
+function pathExists (path) {
+  return fs.access(path).then(() => true).catch(() => false)
+}
+
+module.exports = {
+  pathExists: u(pathExists),
+  pathExistsSync: fs.existsSync
+}