CR

Author: Phoebe Szmucer

src/services/stringCompletions.ts

@@ -647,13 +647,10 @@ function getSupportedExtensionsForModuleResolution(compilerOptions: CompilerOpti
  */
 function getBaseDirectoriesFromRootDirs(rootDirs: string[], basePath: string, scriptDirectory: string, ignoreCase: boolean): readonly string[] {
     // Make all paths absolute/normalized if they are not already
-    rootDirs = rootDirs.map(rootDirectory => normalizePath(isRootedDiskPath(rootDirectory) ? rootDirectory : combinePaths(basePath, rootDirectory)));
+    rootDirs = rootDirs.map(rootDirectory => ensureTrailingDirectorySeparator(normalizePath(isRootedDiskPath(rootDirectory) ? rootDirectory : combinePaths(basePath, rootDirectory))));
 
     // Determine the path to the directory containing the script relative to the root directory it is contained within
-    const relativeDirectory = firstDefined(rootDirs, rootDirectory => {
-        const rootDirectoryWithSlash = rootDirectory.endsWith("/") ? rootDirectory : rootDirectory + "/";
-        return containsPath(rootDirectoryWithSlash, scriptDirectory, basePath, ignoreCase) ? scriptDirectory.substr(rootDirectoryWithSlash.length) : undefined;
-    })!; // TODO: GH#18217
+    const relativeDirectory = firstDefined(rootDirs, rootDirectory => containsPath(rootDirectory, scriptDirectory, basePath, ignoreCase) ? scriptDirectory.substr(rootDirectory.length) : undefined)!; // TODO: GH#18217
 
     // Now find a path for each potential directory that is to be merged with the one containing the script
     return deduplicate<string>(