Expose document highlighting to server.

src/harness/fourslash.ts

@@ -2132,7 +2132,7 @@ module FourSlash {
                 let occurance = occurances[i];
                 if (occurance && occurance.fileName === fileName && occurance.textSpan.start === start && ts.textSpanEnd(occurance.textSpan) === end) {
                     if (typeof isWriteAccess !== "undefined" && occurance.isWriteAccess !== isWriteAccess) {
-                        this.raiseError('verifyOccurancesAtPositionListContains failed - item isWriteAccess value doe not match, actual: ' + occurance.isWriteAccess + ', expected: ' + isWriteAccess + '.');
+                        this.raiseError('verifyOccurancesAtPositionListContains failed - item isWriteAccess value does not match, actual: ' + occurance.isWriteAccess + ', expected: ' + isWriteAccess + '.');
                     }
                     return;
                 }
@@ -2152,6 +2152,51 @@ module FourSlash {
             }
         }
 
+        private getDocumentHighlightsAtCurrentPosition(fileNamesToSearch: string[]) {
+            let filesToSearch = fileNamesToSearch.map(name => this.basePath + "/" + name);
+            return this.languageService.getDocumentHighlights(this.activeFile.fileName, this.currentCaretPosition, filesToSearch);
+        }
+
+        public verifyDocumentHighlightsAtPositionListContains(fileName: string, start: number, end: number, fileNamesToSearch: string[], kind?: string) {
+            this.taoInvalidReason = 'verifyDocumentHighlightsAtPositionListContains NYI';
+
+            let documentHighlights = this.getDocumentHighlightsAtCurrentPosition(fileNamesToSearch);
+
+            if (!documentHighlights || documentHighlights.length === 0) {
+                this.raiseError('verifyDocumentHighlightsAtPositionListContains failed - found 0 highlights, expected at least one.');
+            }
+
+            for (let i = 0; i < documentHighlights.length; i++) if (documentHighlights[i].fileName === fileName) {
+                let { highlightSpans } = documentHighlights[i];
+
+                for (let highlight of highlightSpans) {
+                    if (highlight && highlight.textSpan.start === start && ts.textSpanEnd(highlight.textSpan) === end) {
+                        if (typeof kind !== "undefined" && highlight.kind !== kind) {
+                            this.raiseError('verifyDocumentHighlightsAtPositionListContains failed - item "kind" value does not match, actual: ' + highlight.kind + ', expected: ' + kind + '.');
+                        }
+                        return;
+                    }
+                }
+            }
+
+            let missingItem = { fileName: fileName, start: start, end: end, kind: kind };
+            this.raiseError('verifyOccurancesAtPositionListContains failed - could not find the item: ' + JSON.stringify(missingItem) + ' in the returned list: (' + JSON.stringify(documentHighlights) + ')');
+        }
+
+        public verifyDocumentHighlightsAtPositionListCount(expectedCount: number, fileNamesToSearch: string[]) {
+            this.taoInvalidReason = 'verifyDocumentHighlightsAtPositionListCount NYI';
+
+            let documentHighlights = this.getDocumentHighlightsAtCurrentPosition(fileNamesToSearch);
+            let actualCount = documentHighlights 
+                ? documentHighlights.reduce((currentCount, currentDocumentHighlights) => { 
+                    return currentCount + currentDocumentHighlights.highlightSpans.length}, 0) 
+                : 0;
+
+            if (expectedCount !== actualCount) {
+                this.raiseError('verifyDocumentHighlightsAtPositionListCount failed - actual: ' + actualCount + ', expected:' + expectedCount);
+            }
+        }
+
         // Get the text of the entire line the caret is currently at
         private getCurrentLineContent() {
             let text = this.getFileContent(this.activeFile.fileName);

src/server/client.ts

@@ -528,7 +528,29 @@ namespace ts.server {
         }
 
         getDocumentHighlights(fileName: string, position: number): DocumentHighlights[] {
-            throw new Error("Not Implemented Yet.");
+            var lineOffset = this.positionToOneBasedLineOffset(fileName, position);
+            var args: protocol.FileLocationRequestArgs = {
+                file: fileName,
+                line: lineOffset.line,
+                offset: lineOffset.offset,
+            };
+
+            var request = this.processRequest<protocol.DocumentHighlightsRequest>(CommandNames.DocumentHighlights, args);
+            var response = this.processResponse<protocol.DocumentHighlightsResponse>(request);
+
+            return response.body.map(entry => { // convert ts.server.protocol.DocumentHighlightsItem to ts.DocumentHighlights
+                return {
+                    fileName: entry.file,
+                    highlightSpans: entry.highlightSpans.map(span => { // convert ts.server.protocol.HighlightSpan to ts.HighlighSpan
+                        var start = this.lineOffsetToPosition(entry.file, span.start);
+                        var end = this.lineOffsetToPosition(entry.file, span.end);
+                        return {
+                            textSpan: ts.createTextSpanFromBounds(start, end),
+                            kind: span.kind
+                        };
+                    })
+                };
+            });
         }
 
         getOutliningSpans(fileName: string): OutliningSpan[] {

src/server/protocol.d.ts

@@ -238,6 +238,28 @@ declare namespace ts.server.protocol {
         body?: OccurrencesResponseItem[];
     }
 
+    /**
+      * Get document highlights request; value of command field is
+      * "documentHighlights". Return response giving spans that are relevant
+      * in the file at a given line and column.
+      */
+    export interface DocumentHighlightsRequest extends FileLocationRequest {
+    }
+
+    export interface HighLightSpan extends TextSpan {
+        kind: string
+    }
+
+    export interface DocumentHighlightsItem {
+        file: string,
+        highlightSpans: HighLightSpan[];
+    }
+
+    export interface DocumentHighlightsResponse extends Response {
+        body?: DocumentHighlightsItem[];
+    }
+
+
     /**
       * Find references request; value of command field is
       * "references". Return response giving the file locations that

src/server/session.ts

@@ -89,6 +89,7 @@ namespace ts.server {
         export const NavBar = "navbar";
         export const Navto = "navto";
         export const Occurrences = "occurrences";
+        export const DocumentHighlights = "documentHighlights";
         export const Open = "open";
         export const Quickinfo = "quickinfo";
         export const References = "references";
@@ -313,7 +314,7 @@ namespace ts.server {
             }));
         }
 
-        private getOccurrences(line: number, offset: number, fileName: string): protocol.OccurrencesResponseItem[]{
+        private getOccurrences(line: number, offset: number, fileName: string): protocol.OccurrencesResponseItem[] {
             fileName = ts.normalizePath(fileName);
             let project = this.projectService.getProjectForFile(fileName);
 
@@ -343,6 +344,42 @@ namespace ts.server {
             });
         }
 
+        private getDocumentHighlights(line: number, offset: number, fileName: string): protocol.DocumentHighlightsItem[] {
+            fileName = ts.normalizePath(fileName);
+            let project = this.projectService.getProjectForFile(fileName);
+
+            if (!project) {
+                throw Errors.NoProject;
+            }
+
+            let { compilerService } = project;
+            let position = compilerService.host.lineOffsetToPosition(fileName, line, offset);
+            let filesToSearch = [fileName]; // only search for highlights inside the current file
+            
+            let documentHighlights = compilerService.languageService.getDocumentHighlights(fileName, position, filesToSearch);
+            
+            if (!documentHighlights) {
+                return undefined;
+            }
+
+            return documentHighlights.map(documentHighlight => { // convert ts.DocumentHighlights to ts.server.protocol.DocumentHighlightsItem
+                var file = documentHighlight.fileName;
+                return {
+                    file: file,
+                    highlightSpans: documentHighlight.highlightSpans.map(highlightSpan => { // convert to ts.HighlightSpan to ts.server.protocol.HighlightSpan
+                        let { textSpan, kind } = highlightSpan;
+                        let start = compilerService.host.positionToLineOffset(file, textSpan.start);
+                        let end = compilerService.host.positionToLineOffset(file, ts.textSpanEnd(textSpan));
+                        return {
+                            start: start,
+                            end: end,
+                            kind: kind
+                        }
+                    })
+                }
+            });
+        }
+
         private getProjectInfo(fileName: string, needFileNameList: boolean): protocol.ProjectInfo {
             fileName = ts.normalizePath(fileName)
             let project = this.projectService.getProjectForFile(fileName)
@@ -937,6 +974,10 @@ namespace ts.server {
                 var { line, offset, file: fileName } = <protocol.FileLocationRequestArgs>request.arguments;
                 return {response: this.getOccurrences(line, offset, fileName), responseRequired: true};
             },
+            [CommandNames.DocumentHighlights]: (request: protocol.Request) => {
+                var { line, offset, file: fileName } = <protocol.FileLocationRequestArgs>request.arguments;
+                return {response: this.getDocumentHighlights(line, offset, fileName), responseRequired: true};
+            },
             [CommandNames.ProjectInfo]: (request: protocol.Request) => {
                 var { file, needFileNameList } = <protocol.ProjectInfoRequestArgs>request.arguments;
                 return {response: this.getProjectInfo(file, needFileNameList), responseRequired: true};