public void GenerateSourceFilesHeaderGenerates2047EncodedValue() { // Arrange string headerKey = null, headerValue = null; var context = new Mock <HttpContextBase>(); var response = new Mock <HttpResponseBase>(); response.Setup(c => c.AddHeader(It.IsAny <string>(), It.IsAny <string>())).Callback( (string key, string value) => { headerKey = key; headerValue = value; }); context.Setup(c => c.Response).Returns(response.Object); context.Setup(c => c.Items).Returns(new Hashtable()); var webPageContext = new WebPageContext(context.Object, page: null, model: null); webPageContext.SourceFiles.Add("foo"); webPageContext.SourceFiles.Add("bar"); webPageContext.SourceFiles.Add("λ"); // Act WebPageHttpHandler.GenerateSourceFilesHeader(webPageContext); // Assert Assert.Equal(headerKey, "X-SourceFiles"); Assert.Equal(headerValue, "=?UTF-8?B?Zm9vfGJhcnzOuw==?="); }