Provide default column to getGuideColumn callback

spec/extensions/wrap-guide-spec.coffee

@@ -24,7 +24,7 @@ describe "WrapGuide", ->
 
   describe "@updateGuide", ->
     it "positions the guide at the configured column", ->
-      width = editor.charWidth * wrapGuide.getGuideColumn()
+      width = editor.charWidth * wrapGuide.defaultColumn
       expect(width).toBeGreaterThan(0)
       expect(wrapGuide.position().left).toBe(width)
 
@@ -44,6 +44,16 @@ describe "WrapGuide", ->
       wrapGuide.updateGuide(editor)
       expect(editorPath).toBe(require.resolve('fixtures/sample.js'))
 
+    it "invokes the callback with a default value", ->
+      column = null
+      wrapGuide.getGuideColumn = (path, defaultColumn) ->
+        editorPath = path
+        column = defaultColumn
+        defaultColumn
+
+      wrapGuide.updateGuide(editor)
+      expect(column).toBeGreaterThan(0)
+
     it "uses the function from the config data", ->
       rootView.find('.wrap-guide').remove()
       config =

src/extensions/wrap-guide/wrap-guide.coffee

@@ -20,19 +20,20 @@ class WrapGuide extends View
     @div class: 'wrap-guide'
 
   getGuideColumn: null
+  defaultColumn: 80
 
   initialize: (@rootView, @editor, config = {}) =>
     if typeof config.getGuideColumn is 'function'
       @getGuideColumn = config.getGuideColumn
     else
-      @getGuideColumn = -> 80
+      @getGuideColumn = (path, defaultColumn) -> defaultColumn
 
     @updateGuide(@editor)
     @editor.on 'editor-path-change', => @updateGuide(@editor)
     @rootView.on 'font-size-change', => @updateGuide(@editor)
 
   updateGuide: (editor) ->
-    column = @getGuideColumn(editor.getPath())
+    column = @getGuideColumn(editor.getPath(), @defaultColumn)
     if column > 0
       @css('left', "#{editor.charWidth * column}px").show()
     else