Write spec for TextEditorElement when autoHeight changes

spec/text-editor-element-spec.coffee

@@ -267,6 +267,26 @@ describe "TextEditorElement", ->
       element.getModel().setMini(false)
       expect(element.hasAttribute('mini')).toBe false
 
+  describe "on TextEditor::onDidChangeAutoHeight", ->
+    it "changes the element's height", ->
+      element = new TextEditorElement
+      jasmine.attachToDOM(element)
+      expect(element.style.height).toBe('')
+      element.getModel().setAutoHeight(false)
+
+      waitsForPromise ->
+        atom.views.getNextUpdatePromise()
+
+      runs ->
+        expect(element.style.height).toBe('100%')
+        element.getModel().setAutoHeight(true)
+
+      waitsForPromise ->
+        atom.views.getNextUpdatePromise()
+
+      runs ->
+        expect(element.style.height).toBe('')
+
   describe "events", ->
     element = null
 

src/text-editor-element.coffee

@@ -38,7 +38,8 @@ class TextEditorElement extends HTMLElement
     @setAttribute('tabindex', -1)
 
   initializeContent: (attributes) ->
-    @resetAutoHeight()
+    unless @getModel().getAutoHeight()
+      @style.height = "100%"
 
     if @config.get('editor.useShadowDOM')
       @useShadowDOM = true
@@ -193,8 +194,11 @@ class TextEditorElement extends HTMLElement
     @removeAttribute("mini")
 
   resetAutoHeight: ->
-    unless @getModel().getAutoHeight()
-      @style.height = "100%"
+    @views.updateDocument =>
+      if @getModel().getAutoHeight()
+        @style.height = ""
+      else
+        @style.height = "100%"
 
   addEncodingAttribute: ->
     @dataset.encoding = @model.getEncoding()