         require '../testFixtures/testWithExcludes/a/foo.coffee'
         require '../testFixtures/testWithExcludes/b/bar.coffee'
 
-        assert global[COVERAGE_VAR]?, "Code should have been instrumented"
-        assert ('a/foo.coffee' of global[COVERAGE_VAR]), "Should instrument a/foo.coffee"
-        assert !('b/bar.coffee' of global[COVERAGE_VAR]), "Should not instrument b/bar.coffee"
+        expect(global[COVERAGE_VAR], "Code should have been instrumented").to.exist
+        expect(global[COVERAGE_VAR]['a/foo.coffee'], "Should instrument a/foo.coffee").to.exist
+        expect(global[COVERAGE_VAR]['b/bar.coffee'], "Should not instrument b/bar.coffee").to.not.exist
 
     it "should handle nested recursion correctly", ->
         # From https://github.com/benbria/coffee-coverage/pull/37


        global[COVERAGE_VAR] = {"example.coffee": {}}
        z = eval code
        assert.equal z, 10

        require '../testFixtures/testWithExcludes/a/foo.coffee'
        require '../testFixtures/testWithExcludes/b/bar.coffee'

        expect(global[COVERAGE_VAR], "Code should have been instrumented").to.exist
        expect(global[COVERAGE_VAR]['a/foo.coffee'], "Should instrument a/foo.coffee").to.exist
        expect(global[COVERAGE_VAR]['b/bar.coffee'], "Should not instrument b/bar.coffee").to.not.exist

    it "should exclude directories when dynamically instrumenting code", ->

