Refactor code based on CoffeeScript style guide

https://github.com/polarmobile/coffeescript-style-guide

lib/notational-velocity-view.coffee

@@ -11,7 +11,7 @@ class NotationalVelocityView extends SelectListView
     super
     @addClass('nvatom from-top overlay')
     @rootDirectory = atom.config.get('nvatom.directory')
-    if !fs.existsSync(@rootDirectory)
+    unless fs.existsSync(@rootDirectory)
       throw new Error("The given directory #{@rootDirectory} does not exist. "
         + "Set the note directory to the existing one from Settings.")
     @skipPopulateList = false
@@ -28,7 +28,7 @@ class NotationalVelocityView extends SelectListView
       @populateList() if @documentsLoaded
     @docQuery.on "removed", (fileDetails) =>
       @populateList() if @documentsLoaded
-    if !atom.config.get('nvatom.enableLunrPipeline')
+    unless atom.config.get('nvatom.enableLunrPipeline')
       @docQuery.searchIndex.pipeline.reset()
 
   isCursorProceeded: ->
@@ -42,14 +42,14 @@ class NotationalVelocityView extends SelectListView
     isCursorProceeded = @isCursorProceeded()
 
     for item in filteredItems
-      if item.title.match(///^#{filterQuery}$///i) != null
+      if item.title.match(///^#{filterQuery}$///i) isnt null
         # autoselect
         n = filteredItems.indexOf(item) + 1
         @selectItemView(@list.find("li:nth-child(#{n})"))
         return
 
     for item in filteredItems
-      if item.title.match(///^#{filterQuery}///i) != null && isCursorProceeded
+      if (item.title.match(///^#{filterQuery}///i) isnt null) and isCursorProceeded
         # autocomplete
         @skipPopulateList = true
         editor = @filterEditorView.model
@@ -61,7 +61,7 @@ class NotationalVelocityView extends SelectListView
         @selectItemView(@list.find("li:nth-child(#{n})"))
 
   filter: (filterQuery) ->
-    if filterQuery == "" || filterQuery == undefined
+    if (filterQuery is "") or (filterQuery is undefined)
       return @docQuery.documents
     return @docQuery.search(filterQuery)
 
@@ -156,6 +156,6 @@ class NotationalVelocityView extends SelectListView
       @setError(@getEmptyMessage(@docQuery.documents.length, filteredItems.length))
 
   schedulePopulateList: ->
-    if !@skipPopulateList
+    unless @skipPopulateList
       super
     @skipPopulateList = false

lib/notational-velocity.coffee

@@ -66,14 +66,14 @@ module.exports =
     return unless paneItem?.getURI?()?
     return unless paneItem?.isModified?()
     uri = paneItem.getURI()
-    return unless uri.indexOf(@rootDirectory) == 0
+    return unless uri.indexOf(@rootDirectory) is 0
     return unless path.extname(uri) in atom.config.get('nvatom.extensions')
     paneItem?.save?()
 
   autodelete: (paneItem) ->
     return false unless paneItem?.getURI?()?
     uri = paneItem.getURI()
-    return false unless uri.indexOf(@rootDirectory) == 0
+    return false unless uri.indexOf(@rootDirectory) is 0
     return false unless path.extname(uri) in atom.config.get('nvatom.extensions')
     return false unless paneItem?.isEmpty()
     fs.unlinkSync(uri)
@@ -93,10 +93,10 @@ module.exports =
       throw new Error("Note directory #{noteDirectory} cannot reside within atom packages directory. Please change its value from package settings.")
 
     # Initialize note directory.
-    if !fs.existsSync(noteDirectory)
+    unless fs.existsSync(noteDirectory)
       @tryMigrateFromNotationalVelocity()
       noteDirectory = atom.config.get('nvatom.directory')
-      if !fs.existsSync(noteDirectory)
+      unless fs.existsSync(noteDirectory)
         fs.makeTreeSync(noteDirectory)
         fs.copySync(defaultNoteDirectory, noteDirectory)
 
@@ -109,12 +109,12 @@ module.exports =
     defaultNoteDirectory = path.join(packagesDirectory, 'nvatom', 'notebook')
 
     # notational-velocity does not exist.
-    if prevNoteDirectory == undefined
+    if prevNoteDirectory is undefined
       return
 
     atom.notifications.addInfo('Migrating from notational-velocity package...')
 
-    if !fs.existsSync(prevNoteDirectory)
+    unless fs.existsSync(prevNoteDirectory)
       atom.notifications.addError("notational-velocity.directory #{prevNoteDirectory} does not exists. Migration process is failed.")
       return