Handle case sensitivity when comparing the file names of document span

Fixes #53041

Author: sheetalkamat

src/harness/fourslashImpl.ts

@@ -1569,7 +1569,7 @@ export class TestState {
                 details.push({ location: contextSpanEnd, locationMarker: "|>", span, type: "contextEnd" });
             }
 
-            if (additionalSpan && ts.documentSpansEqual(additionalSpan, span)) {
+            if (additionalSpan && ts.documentSpansEqual(additionalSpan, span, this.languageServiceAdapterHost.useCaseSensitiveFileNames())) {
                 // This span is same as text span
                 groupedSpanForAdditionalSpan = span;
             }

src/server/session.ts

@@ -53,6 +53,7 @@ import {
     formatting,
     getDeclarationFromName,
     getDeclarationOfKind,
+    getDocumentSpansEqualityComparer,
     getEmitDeclarations,
     getEntrypointsFromPackageJsonInfo,
     getLineAndCharacterOfPosition,
@@ -498,8 +499,8 @@ interface ProjectNavigateToItems {
     navigateToItems: readonly NavigateToItem[];
 }
 
-function createDocumentSpanSet(): Set<DocumentSpan> {
-    return createSet(({ textSpan }) => textSpan.start + 100003 * textSpan.length, documentSpansEqual);
+function createDocumentSpanSet(useCaseSensitiveFileNames: boolean): Set<DocumentSpan> {
+    return createSet(({ textSpan }) => textSpan.start + 100003 * textSpan.length, getDocumentSpansEqualityComparer(useCaseSensitiveFileNames));
 }
 
 function getRenameLocationsWorker(
@@ -509,6 +510,7 @@ function getRenameLocationsWorker(
     findInStrings: boolean,
     findInComments: boolean,
     preferences: protocol.UserPreferences,
+    useCaseSensitiveFileNames: boolean,
 ): readonly RenameLocation[] {
     const perProjectResults = getPerProjectReferences(
         projects,
@@ -525,7 +527,7 @@ function getRenameLocationsWorker(
     }
 
     const results: RenameLocation[] = [];
-    const seen = createDocumentSpanSet();
+    const seen = createDocumentSpanSet(useCaseSensitiveFileNames);
 
     perProjectResults.forEach((projectResults, project) => {
         for (const result of projectResults) {
@@ -552,6 +554,7 @@ function getReferencesWorker(
     projects: Projects,
     defaultProject: Project,
     initialLocation: DocumentPosition,
+    useCaseSensitiveFileNames: boolean,
     logger: Logger,
 ): readonly ReferencedSymbol[] {
     const perProjectResults = getPerProjectReferences(
@@ -593,7 +596,7 @@ function getReferencesWorker(
     }
     else {
         // Correct isDefinition properties from projects other than defaultProject
-        const knownSymbolSpans = createDocumentSpanSet();
+        const knownSymbolSpans = createDocumentSpanSet(useCaseSensitiveFileNames);
         for (const referencedSymbol of defaultProjectResults) {
             for (const ref of referencedSymbol.references) {
                 if (ref.isDefinition) {
@@ -632,7 +635,7 @@ function getReferencesWorker(
     // of each definition and merging references from all the projects where they appear.
 
     const results: ReferencedSymbol[] = [];
-    const seenRefs = createDocumentSpanSet(); // It doesn't make sense to have a reference in two definition lists, so we de-dup globally
+    const seenRefs = createDocumentSpanSet(useCaseSensitiveFileNames); // It doesn't make sense to have a reference in two definition lists, so we de-dup globally
 
     // TODO: We might end up with a more logical allocation of refs to defs if we pre-sorted the defs by descending ref-count.
     // Otherwise, it just ends up attached to the first corresponding def we happen to process.  The others may or may not be
@@ -649,7 +652,7 @@ function getReferencesWorker(
                     contextSpan: getMappedContextSpanForProject(referencedSymbol.definition, project),
                 };
 
-            let symbolToAddTo = find(results, o => documentSpansEqual(o.definition, definition));
+            let symbolToAddTo = find(results, o => documentSpansEqual(o.definition, definition, useCaseSensitiveFileNames));
             if (!symbolToAddTo) {
                 symbolToAddTo = { definition, references: [] };
                 results.push(symbolToAddTo);
@@ -1542,7 +1545,10 @@ export class Session<TMessage = string> implements EventSender {
         );
 
         if (needsJsResolution) {
-            const definitionSet = createSet<DefinitionInfo>(d => d.textSpan.start, documentSpansEqual);
+            const definitionSet = createSet<DefinitionInfo>(
+                d => d.textSpan.start,
+                getDocumentSpansEqualityComparer(this.host.useCaseSensitiveFileNames),
+            );
             definitions?.forEach(d => definitionSet.add(d));
             const noDtsProject = project.getNoDtsResolutionProject(file);
             const ls = noDtsProject.getLanguageService();
@@ -1993,6 +1999,7 @@ export class Session<TMessage = string> implements EventSender {
             !!args.findInStrings,
             !!args.findInComments,
             preferences,
+            this.host.useCaseSensitiveFileNames,
         );
         if (!simplifiedResult) return locations;
         return { info: renameInfo, locs: this.toSpanGroups(locations) };
@@ -2029,6 +2036,7 @@ export class Session<TMessage = string> implements EventSender {
             projects,
             this.getDefaultProject(args),
             { fileName: args.file, pos: position },
+            this.host.useCaseSensitiveFileNames,
             this.logger,
         );
 
@@ -2054,7 +2062,7 @@ export class Session<TMessage = string> implements EventSender {
         const preferences = this.getPreferences(toNormalizedPath(fileName));
 
         const references: ReferenceEntry[] = [];
-        const seen = createDocumentSpanSet();
+        const seen = createDocumentSpanSet(this.host.useCaseSensitiveFileNames);
 
         forEachProjectInProjects(projects, /*path*/ undefined, project => {
             if (project.getCancellationToken().isCancellationRequested()) return;

src/services/utilities.ts

@@ -59,7 +59,10 @@ import {
     EndOfFileToken,
     endsWith,
     ensureScriptKind,
+    EqualityComparer,
     EqualityOperator,
+    equateStringsCaseInsensitive,
+    equateStringsCaseSensitive,
     escapeString,
     ExportAssignment,
     ExportDeclaration,
@@ -2663,8 +2666,14 @@ export function textSpansEqual(a: TextSpan | undefined, b: TextSpan | undefined)
     return !!a && !!b && a.start === b.start && a.length === b.length;
 }
 /** @internal */
-export function documentSpansEqual(a: DocumentSpan, b: DocumentSpan): boolean {
-    return a.fileName === b.fileName && textSpansEqual(a.textSpan, b.textSpan);
+export function documentSpansEqual(a: DocumentSpan, b: DocumentSpan, useCaseSensitiveFileNames: boolean): boolean {
+    return (useCaseSensitiveFileNames ? equateStringsCaseSensitive : equateStringsCaseInsensitive)(a.fileName, b.fileName) &&
+        textSpansEqual(a.textSpan, b.textSpan);
+}
+
+/** @internal */
+export function getDocumentSpansEqualityComparer(useCaseSensitiveFileNames: boolean): EqualityComparer<DocumentSpan> {
+    return (a, b) => documentSpansEqual(a, b, useCaseSensitiveFileNames);
 }
 
 /**

tests/baselines/reference/tsserver/rename/with-symlinks-and-case-difference.js

@@ -500,29 +500,6 @@ Info seq  [hh:mm:ss:mss] response:
               }
             ]
           },
-          {
-            "file": "C:/temp/test/project1/index.ts",
-            "locs": [
-              {
-                "start": {
-                  "line": 1,
-                  "offset": 17
-                },
-                "end": {
-                  "line": 1,
-                  "offset": 23
-                },
-                "contextStart": {
-                  "line": 1,
-                  "offset": 1
-                },
-                "contextEnd": {
-                  "line": 2,
-                  "offset": 2
-                }
-              }
-            ]
-          },
           {
             "file": "c:/temp/test/project2/index.ts",
             "locs": [