     x.equals(y).should.be.true
 
   it 'should properly calculate before/after intersect', ->
-    (@intBeforeIntersect.exec(@ctx) == null).should.be.true
+    should(@intBeforeIntersect.exec(@ctx)).be.null
 
   it 'should properly calculate meets intersect', ->
     x = @intMeetsInterval.exec(@ctx)

    y.equals(x).should.be.true

  it 'should properly calculate before/after unions', ->
    (@dateTimeBeforeUnion.exec(@ctx) == null).should.be.true

  it 'should properly calculate meets unions', ->
    x = @dateTimeFullInterval.exec(@ctx)

  @beforeEach ->
    setup @, data

  it 'should properly calculate sameAs except', ->
    should(@dateTimeSameAsExcept.exec(@ctx)).be.null

  it 'should properly calculate before/after except', ->
    @dateTimeBeforeExcept.exec(@ctx).should.eql new Interval(new DateTime(2012, 1, 1, 0, 0, 0, 0), new DateTime(2012, 4, 1, 0, 0, 0, 0))
