🐛 updateContentDimensions when model changes

spec/text-editor-presenter-spec.coffee

@@ -153,7 +153,6 @@ describe "TextEditorPresenter", ->
         expect(stateFn(presenter).tiles[8]).toBeDefined()
         expect(stateFn(presenter).tiles[10]).toBeUndefined()
 
-
       it "updates when ::lineHeight changes", ->
         presenter = buildPresenter(explicitHeight: 6, scrollTop: 0, lineHeight: 1, tileSize: 2)
 
@@ -661,6 +660,16 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> presenter.setScrollTop(50)
           expect(presenter.getState().content.scrollTop).toBe 50
 
+        it "scrolls down automatically when the model is changed", ->
+          presenter = buildPresenter(scrollTop: 0, lineHeight: 10, explicitHeight: 20)
+
+          editor.setText("")
+          editor.insertNewline()
+          expect(presenter.getState().content.scrollTop).toBe(0)
+
+          editor.insertNewline()
+          expect(presenter.getState().content.scrollTop).toBe(10)
+
         it "never exceeds the computed scroll height minus the computed client height", ->
           presenter = buildPresenter(scrollTop: 10, lineHeight: 10, explicitHeight: 50, horizontalScrollbarHeight: 10)
           expectStateUpdate presenter, -> presenter.setScrollTop(100)

src/text-editor-presenter.coffee

@@ -112,6 +112,8 @@ class TextEditorPresenter
 
   observeModel: ->
     @disposables.add @model.onDidChange =>
+      @updateContentDimensions()
+
       @shouldUpdateHeightState = true
       @shouldUpdateVerticalScrollState = true
       @shouldUpdateHorizontalScrollState = true