From a53a076422ecc020b305192ee04e5ae4d0509dd0 Mon Sep 17 00:00:00 2001
From: Rick Waldron <waldron.rick@gmail.com>
Date: Fri, 19 Aug 2016 12:35:26 -0400
Subject: [PATCH] Tests for ensuring preferences.json before write. Closes
 gh-821

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
---
 lib/preferences.js       |  6 +++---
 test/unit/preferences.js | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/lib/preferences.js b/lib/preferences.js
index 3b80e926..79f34b9e 100644
--- a/lib/preferences.js
+++ b/lib/preferences.js
@@ -31,12 +31,12 @@ Preferences.write = function(key, value) {
       .then(contents => {
         contents = contents || {};
         contents[key] = value;
-        fs.ensureFile(preferencesJson, function(err){
+        fs.ensureFile(preferencesJson, error => {
           if (error) {
             log.error('Error writing preference', key, value);
             reject(error);
           } else {
-            fs.writeFile(preferencesJson, JSON.stringify(contents), function(error) {
+            fs.writeFile(preferencesJson, JSON.stringify(contents), error => {
               if (error) {
                 log.error('Error writing preference', key, value);
                 reject(error);
@@ -45,7 +45,7 @@ Preferences.write = function(key, value) {
               }
             });
           }
-        })
+        });
       })
       .catch(error => {
         reject(error);
diff --git a/test/unit/preferences.js b/test/unit/preferences.js
index 07bb607c..c9e5bb07 100644
--- a/test/unit/preferences.js
+++ b/test/unit/preferences.js
@@ -134,6 +134,9 @@ exports['Preferences.write'] = {
     this.exists = this.sandbox.stub(fs, 'exists', (file, handler) => {
       handler(true);
     });
+    this.ensureFile = this.sandbox.stub(fs, 'ensureFile', (file, handler) => {
+      handler(null);
+    });
     this.readFile = this.sandbox.stub(fs, 'readFile', (file, handler) => {
       handler(null, JSON.stringify(this.state));
     });
@@ -160,5 +163,21 @@ exports['Preferences.write'] = {
       test.equal(value, this.state[key]);
       test.done();
     });
+  },
+
+  writeEnsureFileFalse: function(test) {
+    test.expect(1);
+
+    var key = 'key';
+    var value = 'value';
+    var error = 'error';
+
+    this.ensureFile.restore();
+    this.ensureFile = this.sandbox.stub(fs, 'ensureFile', (file, handler) => handler(error));
+
+    Preferences.write(key, value).catch(rejection => {
+      test.equal(rejection, error);
+      test.done();
+    });
   }
 };