public void Find_When_FeatureDoesNotExist_ShouldReturn_Null() { const string testFileName = "test.json"; _fileReader .Setup(x => x.ReadToEnd(testFileName)) .Returns("{\"MY_FEATURE\": 1}"); var sft = new SimpleFeatureToggle(new SimpleFeatureToggleConfiguration { FeatureLoadingStrategy = new FileFeatureLoadingStrategy(testFileName, _fileReader.Object) }); var result = sft.Find("NOT_A_FEATURE"); Assert.IsNull(result); }