public void ProcessAsync()
        {
            var subject = new EmojiAttributeTagHelper();

            var output = GetTagHelperOutput(":grinning:");

            subject.Process(null !, output);
            output.Content.GetContent().Should().Be(":grinning:".Markup());

            output = GetTagHelperOutput(":fail:");
            subject.Process(null !, output);
            output.Content.GetContent().Should().Be(":fail:");
        public void ProcessAsync()
        {
            var subject = new EmojiAttributeTagHelper();

            var output = GetTagHelperOutput(":grinning:");

            subject.Process(null, output);
            output.Content.GetContent().Should().Be(":grinning:".Markup());

            output = GetTagHelperOutput(":fail:");
            subject.Process(null, output);
            output.Content.GetContent().Should().Be(":fail:");

            TagHelperOutput GetTagHelperOutput(string attribute)
            {
                return(new TagHelperOutput("span", new TagHelperAttributeList {
                    { "emoji", attribute }
                }, (flag, encoder) =>
                {
                    var tagHelperContent = new DefaultTagHelperContent();
                    return Task.FromResult <TagHelperContent>(tagHelperContent);
                }));
            }
        }