Add ‘mini’ attribute to TextEditorElement if .isMini() is true on model

spec/text-editor-element-spec.coffee

@@ -1,4 +1,5 @@
 TextEditorElement = require '../src/text-editor-element'
+TextEditor = require '../src/text-editor'
 
 # The rest of text-editor-component-spec will be moved to this file when React
 # is eliminated. This covers only concerns related to the wrapper element for now
@@ -19,6 +20,13 @@ describe "TextEditorElement", ->
       element = jasmineContent.firstChild
       expect(element.getModel().getPlaceholderText()).toBe 'testing'
 
+  describe "when the model is assigned", ->
+    it "adds the 'mini' attribute if .isMini() returns true on the model", ->
+      element = new TextEditorElement
+      model = new TextEditor(mini: true)
+      element.setModel(model)
+      expect(element.hasAttribute('mini')).toBe true
+
   describe "focus and blur handling", ->
     describe "when the editor.useShadowDOM config option is true", ->
       it "proxies focus/blur events to/from the hidden input inside the shadow root", ->

src/text-editor-element.coffee

@@ -70,6 +70,7 @@ class TextEditorElement extends HTMLElement
     @model = model
     @mountComponent()
     @addGrammarScopeAttribute()
+    @addMiniAttributeIfNeeded()
     @model.onDidChangeGrammar => @addGrammarScopeAttribute()
     @addEncodingAttribute()
     @model.onDidChangeEncoding => @addEncodingAttribute()
@@ -131,6 +132,9 @@ class TextEditorElement extends HTMLElement
     grammarScope = @model.getGrammar()?.scopeName?.replace(/\./g, ' ')
     @dataset.grammar = grammarScope
 
+  addMiniAttributeIfNeeded: ->
+    @setAttributeNode(document.createAttribute("mini")) if @model.isMini()
+
   addEncodingAttribute: ->
     @dataset.encoding = @model.getEncoding()