     bus.scan(0, -> 1).onValue((value) -> outputs.push(value))
     expect(outputs).toEqual([0])
   it "yields null seed value", ->
-    outputs = []
-    bus = new Bacon.Bus()
-    bus.scan(null, -> 1).onValue((value) -> outputs.push(value))
-    expect(outputs).toEqual([null])
+    expectPropertyEvents(
+      -> series(1, [1]).scan(null, ->1)
+      [null, 1])
 
 describe "combineTemplate", ->
   it "combines streams according to a template object", ->

    expectPropertyEvents(
      -> series(1, [1, error(), 2]).toProperty()
      [1, error(), 2])

describe "Property.map", ->
  it "maps property values", ->

error = (msg) -> new Bacon.Error(msg)
seqs = []
soon = (f) -> setTimeout f, t(1)
timeUnitMillisecs = 10
series = (interval, values) ->
  Bacon.sequentially(t(interval), values)
repeat = (interval, values) ->
