public async Task SetOutputContentAsync_SetsOutputsContent() { // Arrange var tagHelperContent = new DefaultTagHelperContent(); var content = "Hello from child content"; var executionContext = new TagHelperExecutionContext( "p", tagMode: TagMode.StartTagAndEndTag, items: new Dictionary <object, object>(), uniqueId: string.Empty, executeChildContentAsync: () => { tagHelperContent.SetContent(content); return(Task.FromResult(result: true)); }, startTagHelperWritingScope: _ => { }, endTagHelperWritingScope: () => tagHelperContent); // Act await executionContext.SetOutputContentAsync(); // Assert Assert.Equal(content, executionContext.Output.Content.GetContent()); }