Beispiel #1
0
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (result.Kind != RazorLanguageKind.Razor)
            {
                // We don't care about changes to projected documents here.
                return(result);
            }

            var originalDiagnostics = context.CodeDocument.GetSyntaxTree().Diagnostics;

            var text           = context.SourceText;
            var edits          = result.Edits;
            var changes        = edits.Select(e => e.AsTextChange(text));
            var changedText    = text.WithChanges(changes);
            var changedContext = await context.WithTextAsync(changedText);

            var changedDiagnostics = changedContext.CodeDocument.GetSyntaxTree().Diagnostics;

            // We want to ensure diagnostics didn't change, but since we're formatting things, its expected
            // that some of them might have moved around.
            // This is not 100% correct, as the formatting technically could still cause a compile error,
            // but only if it also fixes one at the same time, so its probably an edge case (if indeed it's
            // at all possible). Also worth noting the order has to be maintained in that case.
            if (!originalDiagnostics.SequenceEqual(changedDiagnostics, LocationIgnoringDiagnosticComparer.Instance))
            {
                if (DebugAssertsEnabled)
                {
                    Debug.Fail("A formatting result was rejected because the formatted text produced different diagnostics compared to the original text.");
                }

                return(new FormattingResult(Array.Empty <TextEdit>()));
            }

            return(result);
        }
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (result.Kind != RazorLanguageKind.Razor)
            {
                // We don't care about changes to projected documents here.
                return(result);
            }

            var originalDiagnostics = context.CodeDocument.GetSyntaxTree().Diagnostics;

            var text           = context.SourceText;
            var edits          = result.Edits;
            var changes        = edits.Select(e => e.AsTextChange(text));
            var changedText    = text.WithChanges(changes);
            var changedContext = await context.WithTextAsync(changedText);

            var changedDiagnostics = changedContext.CodeDocument.GetSyntaxTree().Diagnostics;

            if (!originalDiagnostics.SequenceEqual(changedDiagnostics))
            {
                // Looks like we removed some non-whitespace content as part of formatting. Oops.
                // Discard this formatting result.

                if (DebugAssertsEnabled)
                {
                    Debug.Fail("A formatting result was rejected because the formatted text produced different diagnostics compared to the original text.");
                }

                return(new FormattingResult(Array.Empty <TextEdit>()));
            }

            return(result);
        }
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (context.IsFormatOnType)
            {
                // We don't want to handle OnTypeFormatting here.
                return(result);
            }

            // Apply previous edits if any.
            var originalText   = context.SourceText;
            var changedText    = originalText;
            var changedContext = context;

            if (result.Edits.Length > 0)
            {
                var changes = result.Edits.Select(e => e.AsTextChange(originalText)).ToArray();
                changedText    = changedText.WithChanges(changes);
                changedContext = await context.WithTextAsync(changedText);

                cancellationToken.ThrowIfCancellationRequested();
            }

            // Format the razor bits of the file
            var syntaxTree = changedContext.CodeDocument.GetSyntaxTree();
            var edits      = FormatRazor(changedContext, syntaxTree);

            // Compute the final combined set of edits
            var formattingChanges = edits.Select(e => e.AsTextChange(changedText));

            changedText = changedText.WithChanges(formattingChanges);
            var finalChanges = SourceTextDiffer.GetMinimalTextChanges(originalText, changedText, lineDiffOnly: false);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (!context.IsFormatOnType || result.Kind != RazorLanguageKind.CSharp)
            {
                // We don't want to handle regular formatting or non-C# on type formatting here.
                return(result);
            }

            // Normalize and re-map the C# edits.
            var codeDocument    = context.CodeDocument;
            var csharpText      = SourceText.From(codeDocument.GetCSharpDocument().GeneratedCode);
            var normalizedEdits = NormalizeTextEdits(csharpText, result.Edits);
            var mappedEdits     = RemapTextEdits(codeDocument, normalizedEdits, result.Kind);
            var filteredEdits   = FilterCSharpTextEdits(context, mappedEdits);

            if (filteredEdits.Length == 0)
            {
                // There are no CSharp edits for us to apply. No op.
                return(new FormattingResult(filteredEdits));
            }

            // Find the lines that were affected by these edits.
            var originalText = codeDocument.GetSourceText();
            var changes      = filteredEdits.Select(e => e.AsTextChange(originalText));
            var changedText  = originalText.WithChanges(changes);

            TrackEncompassingChange(originalText, changedText, out var spanBeforeChange, out var spanAfterChange);
            var rangeBeforeEdit = spanBeforeChange.AsRange(originalText);
            var rangeAfterEdit  = spanAfterChange.AsRange(changedText);

            // Create a new formatting context for the changed razor document.
            var changedContext = await context.WithTextAsync(changedText);

            cancellationToken.ThrowIfCancellationRequested();

            // Now, for each affected line in the edited version of the document, remove x amount of spaces
            // at the front to account for extra indentation applied by the C# formatter.
            // This should be based on context.
            // For instance, lines inside @code/@functions block should be reduced one level
            // and lines inside @{} should be reduced by two levels.
            var indentationChanges = AdjustCSharpIndentation(changedContext, (int)rangeAfterEdit.Start.Line, (int)rangeAfterEdit.End.Line);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that modify indentation.
                changedText    = changedText.WithChanges(indentationChanges);
                changedContext = await changedContext.WithTextAsync(changedText);
            }

            // We make an optimistic attempt at fixing corner cases.
            changedText = CleanupDocument(changedContext, rangeAfterEdit);

            // Now that we have made all the necessary changes to the document. Let's diff the original vs final version and return the diff.
            var finalChanges = SourceTextDiffer.GetMinimalTextChanges(originalText, changedText, lineDiffOnly: false);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (context.IsFormatOnType || result.Kind != RazorLanguageKind.Razor)
            {
                // We don't want to handle OnTypeFormatting here.
                return(result);
            }

            // Apply previous edits if any.
            var originalText   = context.SourceText;
            var changedText    = originalText;
            var changedContext = context;

            if (result.Edits.Length > 0)
            {
                var changes = result.Edits.Select(e => e.AsTextChange(originalText)).ToArray();
                changedText    = changedText.WithChanges(changes);
                changedContext = await context.WithTextAsync(changedText);
            }

            cancellationToken.ThrowIfCancellationRequested();

            // Apply original C# edits
            var csharpEdits = await FormatCSharpAsync(changedContext, cancellationToken);

            if (csharpEdits.Count > 0)
            {
                var csharpChanges = csharpEdits.Select(c => c.AsTextChange(changedText));
                changedText    = changedText.WithChanges(csharpChanges);
                changedContext = await changedContext.WithTextAsync(changedText);
            }

            cancellationToken.ThrowIfCancellationRequested();

            // We make an optimistic attempt at fixing corner cases.
            var cleanupChanges = CleanupDocument(changedContext);

            changedText    = changedText.WithChanges(cleanupChanges);
            changedContext = await changedContext.WithTextAsync(changedText);

            cancellationToken.ThrowIfCancellationRequested();

            var indentationChanges = await AdjustIndentationAsync(changedContext, cancellationToken);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that modify indentation.
                changedText = changedText.WithChanges(indentationChanges);
            }

            var finalChanges = SourceTextDiffer.GetMinimalTextChanges(originalText, changedText, lineDiffOnly: false);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
Beispiel #6
0
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (context.IsFormatOnType || result.Kind != RazorLanguageKind.Razor)
            {
                // We don't want to handle OnTypeFormatting here.
                return(result);
            }

            // Apply previous edits if any.
            var originalText   = context.SourceText;
            var changedText    = originalText;
            var changedContext = context;

            if (result.Edits.Length > 0)
            {
                var changes = result.Edits.Select(e => e.AsTextChange(originalText)).ToArray();
                changedText    = changedText.WithChanges(changes);
                changedContext = await context.WithTextAsync(changedText);
            }

            cancellationToken.ThrowIfCancellationRequested();

            // Apply original C# edits
            var csharpEdits = await FormatCSharpAsync(changedContext, cancellationToken);

            if (csharpEdits.Count > 0)
            {
                var csharpChanges = csharpEdits.Select(c => c.AsTextChange(changedText));
                changedText    = changedText.WithChanges(csharpChanges);
                changedContext = await changedContext.WithTextAsync(changedText);
            }

            cancellationToken.ThrowIfCancellationRequested();

            var indentationChanges = await AdjustIndentationAsync(changedContext, cancellationToken);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that modify indentation.
                changedText = changedText.WithChanges(indentationChanges);
            }

            // Allow benchmarks to specify a different diff algorithm
            if (!context.Options.TryGetValue("UseSourceTextDiffer", out var useSourceTextDiffer))
            {
                useSourceTextDiffer = new BooleanNumberString(false);
            }

            var finalChanges = useSourceTextDiffer.Bool ? SourceTextDiffer.GetMinimalTextChanges(originalText, changedText, lineDiffOnly: false) : changedText.GetTextChanges(originalText);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (context.IsFormatOnType || result.Kind != RazorLanguageKind.Razor)
            {
                // We don't want to handle OnTypeFormatting here.
                return(result);
            }

            // Apply previous edits if any.
            var originalText   = context.SourceText;
            var changedText    = originalText;
            var changedContext = context;

            if (result.Edits.Length > 0)
            {
                var changes = result.Edits.Select(e => e.AsTextChange(originalText)).ToArray();
                changedText    = changedText.WithChanges(changes);
                changedContext = await context.WithTextAsync(changedText);
            }

            cancellationToken.ThrowIfCancellationRequested();

            // Apply original C# edits
            var csharpEdits = await FormatCSharpAsync(changedContext, cancellationToken);

            if (csharpEdits.Count > 0)
            {
                var csharpChanges = csharpEdits.Select(c => c.AsTextChange(changedText));
                changedText    = changedText.WithChanges(csharpChanges);
                changedContext = await changedContext.WithTextAsync(changedText);

                _logger.LogTestOnly($"After FormatCSharpAsync:\r\n{changedText}");
            }

            cancellationToken.ThrowIfCancellationRequested();

            var indentationChanges = await AdjustIndentationAsync(changedContext, cancellationToken);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that modify indentation.
                changedText = changedText.WithChanges(indentationChanges);

                _logger.LogTestOnly($"After AdjustIndentationAsync:\r\n{changedText}");
            }

            _logger.LogTestOnly($"Generated C#:\r\n{context.CSharpSourceText}");

            var finalChanges = changedText.GetTextChanges(originalText);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
Beispiel #8
0
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (context.IsFormatOnType)
            {
                // We don't want to handle OnTypeFormatting here.
                return(result);
            }

            var originalText = context.SourceText;

            var htmlEdits = await HtmlFormatter.FormatAsync(context, cancellationToken);

            // Allow benchmarks to specify a different diff algorithm
            if (!context.Options.TryGetValue("UseSourceTextDiffer", out var useSourceTextDiffer))
            {
                useSourceTextDiffer = new BooleanNumberString(false);
            }

            var normalizedEdits = htmlEdits;

            if (useSourceTextDiffer.Bool)
            {
                normalizedEdits = NormalizeTextEdits(originalText, htmlEdits);
            }

            var mappedEdits = RemapTextEdits(context.CodeDocument, normalizedEdits, RazorLanguageKind.Html);
            var changes     = mappedEdits.Select(e => e.AsTextChange(originalText));

            var changedText    = originalText;
            var changedContext = context;

            if (changes.Any())
            {
                changedText = originalText.WithChanges(changes);
                // Create a new formatting context for the changed razor document.
                changedContext = await context.WithTextAsync(changedText);
            }

            var indentationChanges = AdjustRazorIndentation(changedContext);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that adjust indentation.
                changedText = changedText.WithChanges(indentationChanges);
            }

            var finalChanges = useSourceTextDiffer.Bool ? SourceTextDiffer.GetMinimalTextChanges(originalText, changedText, lineDiffOnly: false) : changedText.GetTextChanges(originalText);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            var originalText = context.SourceText;

            TextEdit[] htmlEdits;

            if (context.IsFormatOnType && result.Kind == RazorLanguageKind.Html)
            {
                htmlEdits = await HtmlFormatter.FormatOnTypeAsync(context, cancellationToken).ConfigureAwait(false);
            }
            else if (!context.IsFormatOnType)
            {
                htmlEdits = await HtmlFormatter.FormatAsync(context, cancellationToken).ConfigureAwait(false);
            }
            else
            {
                // We don't want to handle on type formatting requests for other languages
                return(result);
            }

            var changedText    = originalText;
            var changedContext = context;

            _logger.LogTestOnly($"Before HTML formatter:\r\n{changedText}");

            if (htmlEdits.Length > 0)
            {
                var changes = htmlEdits.Select(e => e.AsTextChange(originalText));
                changedText = originalText.WithChanges(changes);
                // Create a new formatting context for the changed razor document.
                changedContext = await context.WithTextAsync(changedText);

                _logger.LogTestOnly($"After normalizedEdits:\r\n{changedText}");
            }

            var indentationChanges = AdjustRazorIndentation(changedContext);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that adjust indentation.
                changedText = changedText.WithChanges(indentationChanges);
                _logger.LogTestOnly($"After AdjustRazorIndentation:\r\n{changedText}");
            }

            var finalChanges = changedText.GetTextChanges(originalText);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
Beispiel #10
0
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (context.IsFormatOnType)
            {
                // We don't want to handle OnTypeFormatting here.
                return(result);
            }

            var originalText = context.SourceText;

            var htmlEdits = await HtmlFormatter.FormatAsync(context, context.Range, cancellationToken);

            var normalizedEdits = NormalizeTextEdits(originalText, htmlEdits);
            var mappedEdits     = RemapTextEdits(context.CodeDocument, normalizedEdits, RazorLanguageKind.Html);
            var changes         = mappedEdits.Select(e => e.AsTextChange(originalText));

            var changedText    = originalText;
            var changedContext = context;

            if (changes.Any())
            {
                changedText = originalText.WithChanges(changes);
                // Create a new formatting context for the changed razor document.
                changedContext = await context.WithTextAsync(changedText);
            }

            var indentationChanges = AdjustRazorIndentation(changedContext);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that adjust indentation.
                changedText = changedText.WithChanges(indentationChanges);
            }

            var finalChanges = SourceTextDiffer.GetMinimalTextChanges(originalText, changedText, lineDiffOnly: false);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
Beispiel #11
0
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (!context.IsFormatOnType || result.Kind != RazorLanguageKind.CSharp)
            {
                // We don't want to handle regular formatting or non-C# on type formatting here.
                return(result);
            }

            // Normalize and re-map the C# edits.
            var codeDocument    = context.CodeDocument;
            var csharpText      = SourceText.From(codeDocument.GetCSharpDocument().GeneratedCode);
            var normalizedEdits = NormalizeTextEdits(csharpText, result.Edits);
            var mappedEdits     = RemapTextEdits(codeDocument, normalizedEdits, result.Kind);
            var filteredEdits   = FilterCSharpTextEdits(context, mappedEdits);

            if (filteredEdits.Length == 0)
            {
                // There are no CSharp edits for us to apply. No op.
                return(new FormattingResult(filteredEdits));
            }

            // Find the lines that were affected by these edits.
            var originalText = codeDocument.GetSourceText();
            var changes      = filteredEdits.Select(e => e.AsTextChange(originalText));

            // Apply the format on type edits sent over by the client.
            var formattedText  = originalText.WithChanges(changes);
            var changedContext = await context.WithTextAsync(formattedText);

            TrackEncompassingChange(originalText, changes, out _, out var spanAfterFormatting);
            var rangeAfterFormatting = spanAfterFormatting.AsRange(formattedText);

            cancellationToken.ThrowIfCancellationRequested();

            // We make an optimistic attempt at fixing corner cases.
            var cleanupChanges = CleanupDocument(changedContext, rangeAfterFormatting);
            var cleanedText    = formattedText.WithChanges(cleanupChanges);

            changedContext = await changedContext.WithTextAsync(cleanedText);

            cancellationToken.ThrowIfCancellationRequested();

            // At this point we should have applied all edits that adds/removes newlines.
            // Let's now ensure the indentation of each of those lines is correct.

            // We only want to adjust the range that was affected.
            // We need to take into account the lines affected by formatting as well as cleanup.
            var cleanupLineDelta = LineDelta(formattedText, cleanupChanges);
            var rangeToAdjust    = new Range(rangeAfterFormatting.Start, new Position(rangeAfterFormatting.End.Line + cleanupLineDelta, 0));

            Debug.Assert(rangeToAdjust.End.IsValid(cleanedText), "Invalid range. This is unexpected.");

            var indentationChanges = AdjustIndentation(changedContext, cancellationToken, rangeToAdjust);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that modify indentation.
                cleanedText = cleanedText.WithChanges(indentationChanges);
            }

            // Now that we have made all the necessary changes to the document. Let's diff the original vs final version and return the diff.
            var finalChanges = SourceTextDiffer.GetMinimalTextChanges(originalText, cleanedText, lineDiffOnly: false);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
Beispiel #12
0
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (!context.IsFormatOnType || result.Kind != RazorLanguageKind.CSharp)
            {
                // We don't want to handle regular formatting or non-C# on type formatting here.
                return(result);
            }

            // Normalize and re-map the C# edits.
            var codeDocument    = context.CodeDocument;
            var csharpText      = codeDocument.GetCSharpSourceText();
            var normalizedEdits = NormalizeTextEdits(csharpText, result.Edits);
            var mappedEdits     = RemapTextEdits(codeDocument, normalizedEdits, result.Kind);
            var filteredEdits   = FilterCSharpTextEdits(context, mappedEdits);

            if (filteredEdits.Length == 0)
            {
                // There are no CSharp edits for us to apply. No op.
                return(new FormattingResult(filteredEdits));
            }

            // Find the lines that were affected by these edits.
            var originalText = codeDocument.GetSourceText();
            var changes      = filteredEdits.Select(e => e.AsTextChange(originalText));

            // Apply the format on type edits sent over by the client.
            var formattedText  = ApplyChangesAndTrackChange(originalText, changes, out _, out var spanAfterFormatting);
            var changedContext = await context.WithTextAsync(formattedText);

            var rangeAfterFormatting = spanAfterFormatting.AsRange(formattedText);

            cancellationToken.ThrowIfCancellationRequested();

            // We make an optimistic attempt at fixing corner cases.
            var cleanupChanges = CleanupDocument(changedContext, rangeAfterFormatting);
            var cleanedText    = formattedText.WithChanges(cleanupChanges);

            changedContext = await changedContext.WithTextAsync(cleanedText);

            cancellationToken.ThrowIfCancellationRequested();

            // At this point we should have applied all edits that adds/removes newlines.
            // Let's now ensure the indentation of each of those lines is correct.

            // We only want to adjust the range that was affected.
            // We need to take into account the lines affected by formatting as well as cleanup.
            var lineDelta = LineDelta(formattedText, cleanupChanges, out var firstPosition, out var lastPosition);

            // Okay hear me out, I know this looks lazy, but it totally makes sense.
            // This method is called with edits that the C# formatter wants to make, and from those edits we work out which
            // other edits to apply etc. Fine, all good so far. BUT its totally possible that the user typed a closing brace
            // in the same position as the C# formatter thought it should be, on the line _after_ the code that the C# formatter
            // reformatted.
            //
            // For example, given:
            // if (true){
            //     }
            //
            // If the C# formatter is happy with the placement of that close brace then this method will get two edits:
            //  * On line 1 to indent the if by 4 spaces
            //  * On line 1 to add a newline and 4 spaces in front of the opening brace
            //
            // We'll happy format lines 1 and 2, and ignore the closing brace altogether. So, by looking one line further
            // we won't have that problem.
            if (rangeAfterFormatting.End.Line + lineDelta < cleanedText.Lines.Count)
            {
                lineDelta++;
            }

            // Now we know how many lines were affected by the cleanup and formatting, but we don't know where those lines are. For example, given:
            //
            // @if (true)
            // {
            //      }
            // else
            // {
            // $$}
            //
            // When typing that close brace, the changes would fix the previous close brace, but the line delta would be 0, so
            // we'd format line 6 and call it a day, even though the formatter made an edit on line 3. To fix this we use the
            // first and last position of edits made above, and make sure our range encompasses them as well. For convenience
            // we calculate these positions in the LineDelta method called above.
            // This is essentially: rangeToAdjust = new Range(Math.Min(firstFormattingEdit, userEdit), Math.Max(lastFormattingEdit, userEdit))
            var start = rangeAfterFormatting.Start;

            if (firstPosition is not null && firstPosition < start)
            {
                start = firstPosition;
            }

            var end = new Position(rangeAfterFormatting.End.Line + lineDelta, 0);

            if (lastPosition is not null && lastPosition < start)
            {
                end = lastPosition;
            }

            var rangeToAdjust = new Range(start, end);

            Debug.Assert(rangeToAdjust.End.IsValid(cleanedText), "Invalid range. This is unexpected.");

            var indentationChanges = await AdjustIndentationAsync(changedContext, cancellationToken, rangeToAdjust);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that modify indentation.
                cleanedText = cleanedText.WithChanges(indentationChanges);
            }

            // Now that we have made all the necessary changes to the document. Let's diff the original vs final version and return the diff.
            var finalChanges = cleanedText.GetTextChanges(originalText);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            return(new FormattingResult(finalEdits));
        }
        public async override Task <FormattingResult> ExecuteAsync(FormattingContext context, FormattingResult result, CancellationToken cancellationToken)
        {
            if (!context.IsFormatOnType || result.Kind != RazorLanguageKind.CSharp)
            {
                // We don't want to handle regular formatting or non-C# on type formatting here.
                return(result);
            }

            // Normalize and re-map the C# edits.
            var codeDocument = context.CodeDocument;
            var csharpText   = codeDocument.GetCSharpSourceText();

            var textEdits = result.Edits;

            if (textEdits.Length == 0)
            {
                if (!DocumentMappingService.TryMapToProjectedDocumentPosition(codeDocument, context.HostDocumentIndex, out _, out var projectedIndex))
                {
                    _logger.LogWarning($"Failed to map to projected position for document {context.Uri}.");
                    return(result);
                }

                // Ask C# for formatting changes.
                var indentationOptions = new RazorIndentationOptions(
                    UseTabs: !context.Options.InsertSpaces,
                    TabSize: context.Options.TabSize,
                    IndentationSize: context.Options.TabSize);
                var autoFormattingOptions = new RazorAutoFormattingOptions(
                    formatOnReturn: true, formatOnTyping: true, formatOnSemicolon: true, formatOnCloseBrace: true);

                var formattingChanges = await RazorCSharpFormattingInteractionService.GetFormattingChangesAsync(
                    context.CSharpWorkspaceDocument,
                    typedChar : context.TriggerCharacter,
                    projectedIndex,
                    indentationOptions,
                    autoFormattingOptions,
                    indentStyle : CodeAnalysis.Formatting.FormattingOptions.IndentStyle.Smart,
                    cancellationToken).ConfigureAwait(false);

                if (formattingChanges.IsEmpty)
                {
                    _logger.LogInformation("Received no results.");
                    return(result);
                }

                textEdits = formattingChanges.Select(change => change.AsTextEdit(csharpText)).ToArray();
                _logger.LogInformation($"Received {textEdits.Length} results from C#.");
            }

            var normalizedEdits = NormalizeTextEdits(csharpText, textEdits, out var originalTextWithChanges);
            var mappedEdits     = RemapTextEdits(codeDocument, normalizedEdits, result.Kind);
            var filteredEdits   = FilterCSharpTextEdits(context, mappedEdits);

            if (filteredEdits.Length == 0)
            {
                // There are no CSharp edits for us to apply. No op.
                return(new FormattingResult(filteredEdits));
            }

            // Find the lines that were affected by these edits.
            var originalText = codeDocument.GetSourceText();
            var changes      = filteredEdits.Select(e => e.AsTextChange(originalText));

            // Apply the format on type edits sent over by the client.
            var formattedText  = ApplyChangesAndTrackChange(originalText, changes, out _, out var spanAfterFormatting);
            var changedContext = await context.WithTextAsync(formattedText);

            var rangeAfterFormatting = spanAfterFormatting.AsRange(formattedText);

            cancellationToken.ThrowIfCancellationRequested();

            // We make an optimistic attempt at fixing corner cases.
            var cleanupChanges = CleanupDocument(changedContext, rangeAfterFormatting);
            var cleanedText    = formattedText.WithChanges(cleanupChanges);

            changedContext = await changedContext.WithTextAsync(cleanedText);

            cancellationToken.ThrowIfCancellationRequested();

            // At this point we should have applied all edits that adds/removes newlines.
            // Let's now ensure the indentation of each of those lines is correct.

            // We only want to adjust the range that was affected.
            // We need to take into account the lines affected by formatting as well as cleanup.
            var lineDelta = LineDelta(formattedText, cleanupChanges, out var firstPosition, out var lastPosition);

            // Okay hear me out, I know this looks lazy, but it totally makes sense.
            // This method is called with edits that the C# formatter wants to make, and from those edits we work out which
            // other edits to apply etc. Fine, all good so far. BUT its totally possible that the user typed a closing brace
            // in the same position as the C# formatter thought it should be, on the line _after_ the code that the C# formatter
            // reformatted.
            //
            // For example, given:
            // if (true){
            //     }
            //
            // If the C# formatter is happy with the placement of that close brace then this method will get two edits:
            //  * On line 1 to indent the if by 4 spaces
            //  * On line 1 to add a newline and 4 spaces in front of the opening brace
            //
            // We'll happy format lines 1 and 2, and ignore the closing brace altogether. So, by looking one line further
            // we won't have that problem.
            if (rangeAfterFormatting.End.Line + lineDelta < cleanedText.Lines.Count)
            {
                lineDelta++;
            }

            // Now we know how many lines were affected by the cleanup and formatting, but we don't know where those lines are. For example, given:
            //
            // @if (true)
            // {
            //      }
            // else
            // {
            // $$}
            //
            // When typing that close brace, the changes would fix the previous close brace, but the line delta would be 0, so
            // we'd format line 6 and call it a day, even though the formatter made an edit on line 3. To fix this we use the
            // first and last position of edits made above, and make sure our range encompasses them as well. For convenience
            // we calculate these positions in the LineDelta method called above.
            // This is essentially: rangeToAdjust = new Range(Math.Min(firstFormattingEdit, userEdit), Math.Max(lastFormattingEdit, userEdit))
            var start = rangeAfterFormatting.Start;

            if (firstPosition is not null && firstPosition < start)
            {
                start = firstPosition;
            }

            var end = new Position(rangeAfterFormatting.End.Line + lineDelta, 0);

            if (lastPosition is not null && lastPosition < start)
            {
                end = lastPosition;
            }

            var rangeToAdjust = new Range(start, end);

            Debug.Assert(rangeToAdjust.End.IsValid(cleanedText), "Invalid range. This is unexpected.");

            var indentationChanges = await AdjustIndentationAsync(changedContext, cancellationToken, rangeToAdjust);

            if (indentationChanges.Count > 0)
            {
                // Apply the edits that modify indentation.
                cleanedText = cleanedText.WithChanges(indentationChanges);
            }

            // Now that we have made all the necessary changes to the document. Let's diff the original vs final version and return the diff.
            var finalChanges = cleanedText.GetTextChanges(originalText);
            var finalEdits   = finalChanges.Select(f => f.AsTextEdit(originalText)).ToArray();

            if (context.AutomaticallyAddUsings)
            {
                // Because we need to parse the C# code twice for this operation, lets do a quick check to see if its even necessary
                if (textEdits.Any(e => e.NewText.IndexOf("using") != -1))
                {
                    finalEdits = await AddUsingStatementEditsAsync(codeDocument, finalEdits, csharpText, originalTextWithChanges, cancellationToken);
                }
            }

            return(new FormattingResult(finalEdits));
        }