follow style guidelines

atom/browser/api/lib/dialog.coffee

@@ -91,10 +91,10 @@ module.exports =
 
     throw new TypeError('Buttons need to be array') unless Array.isArray options.buttons
 
-    options.title              ?= ''
-    options.message            ?= ''
-    options.detail             ?= ''
-    options.icon               ?= null
+    options.title ?= ''
+    options.message ?= ''
+    options.detail ?= ''
+    options.icon ?= null
     options.defaultId ?= -1
 
     # Choose a default button to get selected when dialog is cancelled.

atom/browser/ui/message_box_mac.mm

@@ -84,9 +84,9 @@ NSAlert* CreateNSAlert(NativeWindow* parent_window,
     [button setTag:i];
 
     if (i == (size_t)default_id) {
-      // focus the button at default_id if the user opted to do so.
+      // Focus the button at default_id if the user opted to do so.
       // The first button added gets set as the default selected.
-      // So remove that default, and make the requested button the default
+      // So remove that default, and make the requested button the default.
       [[[alert buttons] objectAtIndex:0] setKeyEquivalent:@""];
       [button setKeyEquivalent:@"\r"];
     }

docs/api/dialog.md

@@ -87,7 +87,8 @@ will be passed via `callback(filename)`
   `"warning"`. On Windows, "question" displays the same icon as "info", unless
   you set an icon using the "icon" option.
   * `buttons` Array - Array of texts for buttons.
-  * `defaultId` Integer - Index of the button in the buttons array which will be selected by default when the message box opens.
+  * `defaultId` Integer - Index of the button in the buttons array which will
+    be selected by default when the message box opens.
   * `title` String - Title of the message box, some platforms will not show it.
   * `message` String - Content of the message box.
   * `detail` String - Extra information of the message.