public void Execute_CanHandleSingleLengthTagHelperPrefix()
        {
            // Arrange
            var engine = RazorEngine.Create(builder =>
            {
                builder.AddTagHelpers(new TagHelperDescriptor[0]);
            });

            var phase = new DefaultRazorTagHelperBinderPhase()
            {
                Engine = engine,
            };
            var expectedDiagnostics = new[]
            {
                RazorDiagnosticFactory.CreateParsing_UnterminatedStringLiteral(
                    new SourceSpan(new SourceLocation(17 + Environment.NewLine.Length, 1, 17), contentLength: 1)),
                RazorDiagnosticFactory.CreateParsing_InvalidTagHelperPrefixValue(
                    new SourceSpan(new SourceLocation(17 + Environment.NewLine.Length, 1, 17), contentLength: 1), "tagHelperPrefix", '\"', "\""),
            };

            var content =
                @"
@tagHelperPrefix """;
            var sourceDocument = TestRazorSourceDocument.Create(content, filePath: null);
            var codeDocument   = RazorCodeDocument.Create(sourceDocument);
            var originalTree   = RazorSyntaxTree.Parse(sourceDocument);

            codeDocument.SetSyntaxTree(originalTree);

            // Act
            phase.Execute(codeDocument);

            // Assert
            var rewrittenTree  = codeDocument.GetSyntaxTree();
            var directiveValue = rewrittenTree.Root.Children.OfType <Block>().First().Children.Last() as Span;
            var chunkGenerator = Assert.IsType <TagHelperPrefixDirectiveChunkGenerator>(directiveValue.ChunkGenerator);

            Assert.Equal(expectedDiagnostics, chunkGenerator.Diagnostics);
        }
        public void Execute_CanHandleSingleLengthRemoveTagHelperDirective()
        {
            // Arrange
            var projectEngine = RazorProjectEngine.Create(builder =>
            {
                builder.AddTagHelpers(new TagHelperDescriptor[0]);
            });

            var phase = new DefaultRazorTagHelperBinderPhase()
            {
                Engine = projectEngine.Engine,
            };
            var expectedDiagnostics = new[]
            {
                RazorDiagnosticFactory.CreateParsing_UnterminatedStringLiteral(
                    new SourceSpan(new SourceLocation(17 + Environment.NewLine.Length, 1, 17), contentLength: 1)),
                RazorDiagnosticFactory.CreateParsing_InvalidTagHelperLookupText(
                    new SourceSpan(new SourceLocation(17 + Environment.NewLine.Length, 1, 17), contentLength: 1), "\"")
            };

            var content =
                @"
@removeTagHelper """;
            var sourceDocument = TestRazorSourceDocument.Create(content, filePath: null);
            var codeDocument   = RazorCodeDocument.Create(sourceDocument);
            var originalTree   = RazorSyntaxTree.Parse(sourceDocument);

            codeDocument.SetSyntaxTree(originalTree);

            // Act
            phase.Execute(codeDocument);

            // Assert
            var rewrittenTree  = codeDocument.GetSyntaxTree();
            var erroredNode    = rewrittenTree.Root.DescendantNodes().First(n => n.GetSpanContext()?.ChunkGenerator is RemoveTagHelperChunkGenerator);
            var chunkGenerator = Assert.IsType <RemoveTagHelperChunkGenerator>(erroredNode.GetSpanContext().ChunkGenerator);

            Assert.Equal(expectedDiagnostics, chunkGenerator.Diagnostics);
        }