Merge pull request #28886 from Microsoft/sourceMapDecoder

Enhancements to SourceMap decoder from tsserver

Author: sheetalkamat

src/compiler/program.ts

@@ -787,7 +787,13 @@ namespace ts {
         // Key is a file name. Value is the (non-empty, or undefined) list of files that redirect to it.
         let redirectTargetsMap = createMultiMap<string>();
 
-        const filesByName = createMap<SourceFile | undefined>();
+        /**
+         * map with
+         * - SourceFile if present
+         * - false if sourceFile missing for source of project reference redirect
+         * - undefined otherwise
+         */
+        const filesByName = createMap<SourceFile | false | undefined>();
         let missingFilePaths: ReadonlyArray<Path> | undefined;
         // stores 'filename -> file association' ignoring case
         // used to track cases when two file names differ only in casing
@@ -854,7 +860,7 @@ namespace ts {
                 }
             }
 
-            missingFilePaths = arrayFrom(filesByName.keys(), p => <Path>p).filter(p => !filesByName.get(p));
+            missingFilePaths = arrayFrom(mapDefinedIterator(filesByName.entries(), ([path, file]) => file === undefined ? path as Path : undefined));
             files = stableSort(processingDefaultLibFiles, compareDefaultLibFiles).concat(processingOtherFiles);
             processingDefaultLibFiles = undefined;
             processingOtherFiles = undefined;
@@ -1567,7 +1573,7 @@ namespace ts {
         }
 
         function getSourceFileByPath(path: Path): SourceFile | undefined {
-            return filesByName.get(path);
+            return filesByName.get(path) || undefined;
         }
 
         function getDiagnosticsHelper<T extends Diagnostic>(
@@ -2104,7 +2110,7 @@ namespace ts {
 
         /** This should have similar behavior to 'processSourceFile' without diagnostics or mutation. */
         function getSourceFileFromReference(referencingFile: SourceFile, ref: FileReference): SourceFile | undefined {
-            return getSourceFileFromReferenceWorker(resolveTripleslashReference(ref.fileName, referencingFile.fileName), fileName => filesByName.get(toPath(fileName)));
+            return getSourceFileFromReferenceWorker(resolveTripleslashReference(ref.fileName, referencingFile.fileName), fileName => filesByName.get(toPath(fileName)) || undefined);
         }
 
         function getSourceFileFromReferenceWorker(
@@ -2235,7 +2241,7 @@ namespace ts {
                     }
                 }
 
-                return file;
+                return file || undefined;
             }
 
             let redirectedPath: Path | undefined;
@@ -2327,9 +2333,12 @@ namespace ts {
         }
 
         function addFileToFilesByName(file: SourceFile | undefined, path: Path, redirectedPath: Path | undefined) {
-            filesByName.set(path, file);
             if (redirectedPath) {
                 filesByName.set(redirectedPath, file);
+                filesByName.set(path, file || false);
+            }
+            else {
+                filesByName.set(path, file);
             }
         }
 

src/compiler/scanner.ts

@@ -337,13 +337,14 @@ namespace ts {
         return result;
     }
 
-    export function getPositionOfLineAndCharacter(sourceFile: SourceFileLike, line: number, character: number): number {
-        return computePositionOfLineAndCharacter(getLineStarts(sourceFile), line, character, sourceFile.text);
-    }
-
+    export function getPositionOfLineAndCharacter(sourceFile: SourceFileLike, line: number, character: number): number;
     /* @internal */
-    export function getPositionOfLineAndCharacterWithEdits(sourceFile: SourceFileLike, line: number, character: number): number {
-        return computePositionOfLineAndCharacter(getLineStarts(sourceFile), line, character, sourceFile.text, /*allowEdits*/ true);
+    // tslint:disable-next-line:unified-signatures
+    export function getPositionOfLineAndCharacter(sourceFile: SourceFileLike, line: number, character: number, allowEdits?: true): number;
+    export function getPositionOfLineAndCharacter(sourceFile: SourceFileLike, line: number, character: number, allowEdits?: true): number {
+        return sourceFile.getPositionOfLineAndCharacter ?
+            sourceFile.getPositionOfLineAndCharacter(line, character, allowEdits) :
+            computePositionOfLineAndCharacter(getLineStarts(sourceFile), line, character, sourceFile.text, allowEdits);
     }
 
     /* @internal */

src/compiler/sourcemap.ts

@@ -266,14 +266,24 @@ namespace ts {
     const sourceMapCommentRegExp = /^\/\/[@#] source[M]appingURL=(.+)\s*$/;
     const whitespaceOrMapCommentRegExp = /^\s*(\/\/[@#] .*)?$/;
 
+    export interface LineInfo {
+        getLineCount(): number;
+        getLineText(line: number): string;
+    }
+
+    export function getLineInfo(text: string, lineStarts: ReadonlyArray<number>): LineInfo {
+        return {
+            getLineCount: () => lineStarts.length,
+            getLineText: line => text.substring(lineStarts[line], lineStarts[line + 1])
+        };
+    }
+
     /**
      * Tries to find the sourceMappingURL comment at the end of a file.
-     * @param text The source text of the file.
-     * @param lineStarts The line starts of the file.
      */
-    export function tryGetSourceMappingURL(text: string, lineStarts: ReadonlyArray<number> = computeLineStarts(text)) {
-        for (let index = lineStarts.length - 1; index >= 0; index--) {
-            const line = text.substring(lineStarts[index], lineStarts[index + 1]);
+    export function tryGetSourceMappingURL(lineInfo: LineInfo) {
+        for (let index = lineInfo.getLineCount() - 1; index >= 0; index--) {
+            const line = lineInfo.getLineText(index);
             const comment = sourceMapCommentRegExp.exec(line);
             if (comment) {
                 return comment[1];
@@ -573,7 +583,10 @@ namespace ts {
     }
 
     function compareSourcePositions(left: SourceMappedPosition, right: SourceMappedPosition) {
-        return compareValues(left.sourceIndex, right.sourceIndex);
+        // Compares sourcePosition without comparing sourceIndex
+        // since the mappings are grouped by sourceIndex
+        Debug.assert(left.sourceIndex === right.sourceIndex);
+        return compareValues(left.sourcePosition, right.sourcePosition);
     }
 
     function compareGeneratedPositions(left: MappedPosition, right: MappedPosition) {
@@ -592,11 +605,9 @@ namespace ts {
         const mapDirectory = getDirectoryPath(mapPath);
         const sourceRoot = map.sourceRoot ? getNormalizedAbsolutePath(map.sourceRoot, mapDirectory) : mapDirectory;
         const generatedAbsoluteFilePath = getNormalizedAbsolutePath(map.file, mapDirectory);
-        const generatedCanonicalFilePath = host.getCanonicalFileName(generatedAbsoluteFilePath) as Path;
-        const generatedFile = host.getSourceFileLike(generatedCanonicalFilePath);
+        const generatedFile = host.getSourceFileLike(generatedAbsoluteFilePath);
         const sourceFileAbsolutePaths = map.sources.map(source => getNormalizedAbsolutePath(source, sourceRoot));
-        const sourceFileCanonicalPaths = sourceFileAbsolutePaths.map(source => host.getCanonicalFileName(source) as Path);
-        const sourceToSourceIndexMap = createMapFromEntries(sourceFileCanonicalPaths.map((source, i) => [source, i] as [string, number]));
+        const sourceToSourceIndexMap = createMapFromEntries(sourceFileAbsolutePaths.map((source, i) => [host.getCanonicalFileName(source), i] as [string, number]));
         let decodedMappings: ReadonlyArray<MappedPosition> | undefined;
         let generatedMappings: SortedReadonlyArray<MappedPosition> | undefined;
         let sourceMappings: ReadonlyArray<SortedReadonlyArray<SourceMappedPosition>> | undefined;
@@ -608,16 +619,15 @@ namespace ts {
 
         function processMapping(mapping: Mapping): MappedPosition {
             const generatedPosition = generatedFile !== undefined
-                ? getPositionOfLineAndCharacterWithEdits(generatedFile, mapping.generatedLine, mapping.generatedCharacter)
+                ? getPositionOfLineAndCharacter(generatedFile, mapping.generatedLine, mapping.generatedCharacter, /*allowEdits*/ true)
                 : -1;
             let source: string | undefined;
             let sourcePosition: number | undefined;
             if (isSourceMapping(mapping)) {
-                const sourceFilePath = sourceFileCanonicalPaths[mapping.sourceIndex];
-                const sourceFile = host.getSourceFileLike(sourceFilePath);
+                const sourceFile = host.getSourceFileLike(sourceFileAbsolutePaths[mapping.sourceIndex]);
                 source = map.sources[mapping.sourceIndex];
                 sourcePosition = sourceFile !== undefined
-                    ? getPositionOfLineAndCharacterWithEdits(sourceFile, mapping.sourceLine, mapping.sourceCharacter)
+                    ? getPositionOfLineAndCharacter(sourceFile, mapping.sourceLine, mapping.sourceCharacter, /*allowEdits*/ true)
                     : -1;
             }
             return {

src/compiler/types.ts

@@ -2617,6 +2617,8 @@ namespace ts {
     export interface SourceFileLike {
         readonly text: string;
         lineMap?: ReadonlyArray<number>;
+        /* @internal */
+        getPositionOfLineAndCharacter?(line: number, character: number, allowEdits?: true): number;
     }
 
 
@@ -5531,9 +5533,9 @@ namespace ts {
 
     /* @internal */
     export interface DocumentPositionMapperHost {
-        getSourceFileLike(path: Path): SourceFileLike | undefined;
+        getSourceFileLike(fileName: string): SourceFileLike | undefined;
         getCanonicalFileName(path: string): string;
-        log?(text: string): void;
+        log(text: string): void;
     }
 
     /**

src/harness/sourceMapRecorder.ts

@@ -69,7 +69,7 @@ namespace Harness.SourceMapRecorder {
             SourceMapDecoder.initializeSourceMapDecoding(sourceMapData);
             sourceMapRecorder.WriteLine("===================================================================");
             sourceMapRecorder.WriteLine("JsFile: " + sourceMapData.sourceMap.file);
-            sourceMapRecorder.WriteLine("mapUrl: " + ts.tryGetSourceMappingURL(jsFile.text, jsLineMap));
+            sourceMapRecorder.WriteLine("mapUrl: " + ts.tryGetSourceMappingURL(ts.getLineInfo(jsFile.text, jsLineMap)));
             sourceMapRecorder.WriteLine("sourceRoot: " + sourceMapData.sourceMap.sourceRoot);
             sourceMapRecorder.WriteLine("sources: " + sourceMapData.sourceMap.sources);
             if (sourceMapData.sourceMap.sourcesContent) {