From 730f34b214dec8bc6d5d4aa442c47031e65a33ba Mon Sep 17 00:00:00 2001
From: nick spragg <nick.spragg@bbc.co.uk>
Date: Fri, 13 Jan 2017 20:24:04 +0000
Subject: [PATCH] Feature: Add methods for checking permissions

---
 src/file.js                                | 20 ++++++++++
 test/file.js                               | 46 ++++++++++++++++++++++
 test/fixtures/permissions/executable.sh    |  0
 test/fixtures/permissions/notExecutable.sh |  0
 test/fixtures/permissions/notWritable.json |  0
 test/fixtures/permissions/readWrite.json   |  0
 6 files changed, 66 insertions(+)
 create mode 100755 test/fixtures/permissions/executable.sh
 create mode 100644 test/fixtures/permissions/notExecutable.sh
 create mode 100644 test/fixtures/permissions/notWritable.json
 create mode 100644 test/fixtures/permissions/readWrite.json

diff --git a/src/file.js b/src/file.js
index ac50687..77215df 100644
--- a/src/file.js
+++ b/src/file.js
@@ -36,6 +36,14 @@ class File {
     return pathname.split(path.sep).length - 1;
   }
 
+  _access(permission) {
+    let hasPermission = true;
+
+    return fsp.accessAsync(this._pathname, permission)
+      .catch(() => hasPermission = false)
+      .then(() => hasPermission);
+  }
+
   isDirectorySync() {
     return this._getStatsSync().isDirectory();
   }
@@ -120,6 +128,18 @@ class File {
   sizeSync() {
     return this._getStatsSync().size;
   }
+
+  isWritable() {
+    return this._access(fs.W_OK);
+  }
+
+  isReadable() {
+    return this._access(fs.R_OK);
+  }
+
+  isExecutable() {
+    return this._access(fs.X_OK);
+  }
 }
 
 module.exports.create = (filename) => {
diff --git a/test/file.js b/test/file.js
index 3518ad2..e19f26f 100644
--- a/test/file.js
+++ b/test/file.js
@@ -398,4 +398,50 @@ describe('File', () => {
       assert.equal(file.getName(), getAbsolutePath('dates/a.txt'));
     });
   });
+
+  describe('.isWritable', () => {
+    it('returns true when the file has write permission', () => {
+      const file = File.create(getAbsolutePath('justFiles/a.json'));
+      file.isWritable()
+        .then((isWritable) => {
+          assert.strictEqual(isWritable, true);
+        });
+    });
+
+    it('returns false when the file does not have write permission', () => {
+      const file = File.create(getAbsolutePath('permissions/notWritable.json'));
+      file.isWritable()
+        .then((isWritable) => {
+          assert.strictEqual(isWritable, false);
+        });
+    });
+  });
+
+  describe('.isReadable', () => {
+    it('returns true when the file has read permission', () => {
+      const file = File.create(getAbsolutePath('permissions/readWrite.json'));
+      file.isReadable()
+        .then((isReadable) => {
+          assert.strictEqual(isReadable, true);
+        });
+    });
+  });
+
+  describe('.isExecutable', () => {
+    it('returns true when the file has read permission', () => {
+      const file = File.create(getAbsolutePath('permissions/executable.sh'));
+      file.isReadable()
+        .then((isExecutable) => {
+          assert.strictEqual(isExecutable, true);
+        });
+    });
+
+    it('returns false when the file does not have read permission', () => {
+      const file = File.create(getAbsolutePath('permissions/notExecutable.sh'));
+      file.isExecutable()
+        .then((isExecutable) => {
+          assert.strictEqual(isExecutable, false);
+        });
+    });
+  });
 });
diff --git a/test/fixtures/permissions/executable.sh b/test/fixtures/permissions/executable.sh
new file mode 100755
index 0000000..e69de29
diff --git a/test/fixtures/permissions/notExecutable.sh b/test/fixtures/permissions/notExecutable.sh
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/permissions/notWritable.json b/test/fixtures/permissions/notWritable.json
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/permissions/readWrite.json b/test/fixtures/permissions/readWrite.json
new file mode 100644
index 0000000..e69de29