Add Buffer.markersForPosition and coerce marker ids to strings

spec/app/buffer-spec.coffee

@@ -928,6 +928,15 @@ describe 'Buffer', ->
           buffer.undo()
           expect(buffer.getMarkerRange(marker4)).toEqual [[4, 20], [4, 23]]
 
+    describe ".markersForPosition(position)", ->
+      it "returns all markers that intersect the given position", ->
+        m1 = buffer.markRange([[3, 4], [3, 10]])
+        m2 = buffer.markRange([[3, 4], [3, 5]])
+        m3 = buffer.markPosition([3, 5])
+        expect(_.difference(buffer.markersForPosition([3, 5]), [m1, m2, m3]).length).toBe 0
+        expect(_.difference(buffer.markersForPosition([3, 4]), [m1, m2]).length).toBe 0
+        expect(_.difference(buffer.markersForPosition([3, 10]), [m1]).length).toBe 0
+
   describe "anchors", ->
     [anchor, destroyHandler] = []
 

src/app/buffer-marker.coffee

@@ -121,6 +121,9 @@ class BufferMarker
   unobserve: (callback) ->
     _.remove(@observers, callback)
 
+  containsPoint: (point) ->
+    @getRange().containsPoint(point)
+
   notifyObservers: ({oldHeadPosition, newHeadPosition, oldTailPosition, newTailPosition, bufferChanged}) ->
     return if @suppressObserverNotification
     return if _.isEqual(newHeadPosition, oldHeadPosition) and _.isEqual(newTailPosition, oldTailPosition)

src/app/buffer.coffee

@@ -273,7 +273,7 @@ class Buffer
 
   markRange: (range, options={}) ->
     marker = new BufferMarker(_.defaults({
-      id: @nextMarkerId++
+      id: (@nextMarkerId++).toString()
       buffer: this
       range
     }, options))
@@ -323,6 +323,13 @@ class Buffer
   observeMarker: (id, callback) ->
     @validMarkers[id]?.observe(callback)
 
+  markersForPosition: (bufferPosition) ->
+    bufferPosition = Point.fromObject(bufferPosition)
+    ids = []
+    for id, marker of @validMarkers
+      ids.push(id) if marker.containsPoint(bufferPosition)
+    ids
+
   getAnchors: -> new Array(@anchors...)
 
   addAnchor: (options) ->