Address more PR comments

src/server/tsconfig.json

@@ -12,7 +12,7 @@
         { "path": "../compiler" },
         { "path": "../jsTyping" },
         { "path": "../services" },
-        { "path": "../vfs", "prepend": true }
+        { "path": "../vfs" }
     ],
     "files": [
         "types.ts",

src/testRunner/unittests/tsserver/webServer.ts

@@ -3,6 +3,7 @@ namespace ts.projectSystem {
         class TestWorkerSession extends server.WorkerSession {
             constructor(host: server.ServerHost, webHost: server.HostWithWriteMessage, options: Partial<server.StartSessionOptions>, logger: server.Logger) {
                 super(
+                    host,
                     host,
                     webHost,
                     {

src/tsserver/nodeServer.ts

@@ -383,7 +383,7 @@ namespace ts.server {
         return eventPort !== undefined && !isNaN(eventPort) ? eventPort : undefined;
     }
 
-    function startNodeSession(options: StartSessionOptions, logger: Logger, cancellationToken: ServerCancellationToken, fs: ServerHost) {
+    function startNodeSession(options: StartSessionOptions, logger: Logger, cancellationToken: ServerCancellationToken, fshost: ServerHost) {
         const childProcess: {
             fork(modulePath: string, args: string[], options?: { execArgv: string[], env?: MapLike<string> }): NodeChildProcess;
         } = require("child_process");
@@ -680,7 +680,7 @@ namespace ts.server {
                     this.event(body, eventName);
                 };
 
-                const host = fs; // sys as ServerHost;
+                const host = sys as ServerHost;
 
                 const typingsInstaller = disableAutomaticTypingAcquisition
                     ? undefined
@@ -688,7 +688,7 @@ namespace ts.server {
 
                 super({
                     host,
-                    fshost: host,
+                    fshost,
                     cancellationToken,
                     ...options,
                     typingsInstaller: typingsInstaller || nullTypingsInstaller,
@@ -789,7 +789,7 @@ namespace ts.server {
 
         const eventPort: number | undefined = parseEventPort(findArgument("--eventPort"));
         const typingSafeListLocation = findArgument(Arguments.TypingSafeListLocation)!; // TODO: GH#18217
-        const typesMapLocation = findArgument(Arguments.TypesMapLocation) || combinePaths(getDirectoryPath(fs.getExecutingFilePath()), "typesMap.json");
+        const typesMapLocation = findArgument(Arguments.TypesMapLocation) || combinePaths(getDirectoryPath(fshost.getExecutingFilePath()), "typesMap.json");
         const npmLocation = findArgument(Arguments.NpmLocation);
         const validateDefaultNpmLocation = hasArgument(Arguments.ValidateDefaultNpmLocation);
         const disableAutomaticTypingAcquisition = hasArgument("--disableAutomaticTypingAcquisition");

src/tsserver/server.ts

@@ -30,14 +30,15 @@ namespace ts.server {
         unknownServerMode?: string;
         startSession: (option: StartSessionOptions, logger: Logger, cancellationToken: ServerCancellationToken, fs: ServerHost) => void;
     }
-    function start({ args, logger, cancellationToken, serverMode, unknownServerMode, startSession: startServer }: StartInput, platform: string, fs: ServerHost) {
+    function start({ args, logger, cancellationToken, serverMode, unknownServerMode, startSession: startServer }: StartInput, platform: string) {
         const syntaxOnly = hasArgument("--syntaxOnly");
+        const vfs = hasArgument("--vfs");
 
         logger.info(`Starting TS Server`);
         logger.info(`Version: ${version}`);
         logger.info(`Arguments: ${args.join(" ")}`);
         logger.info(`Platform: ${platform} NodeVersion: ${getNodeMajorVersion()} CaseSensitive: ${sys.useCaseSensitiveFileNames}`);
-        logger.info(`ServerMode: ${serverMode} syntaxOnly: ${syntaxOnly} hasUnknownServerMode: ${unknownServerMode}`);
+        logger.info(`ServerMode: ${serverMode} syntaxOnly: ${syntaxOnly} hasUnknownServerMode: ${unknownServerMode} vfs: ${vfs}`);
 
         setStackTraceLimit();
 
@@ -57,6 +58,7 @@ namespace ts.server {
         console.warn = (...args) => logger.msg(args.length === 1 ? args[0] : args.join(", "), Msg.Err);
         console.error = (...args) => logger.msg(args.length === 1 ? args[0] : args.join(", "), Msg.Err);
 
+        const fshost = vfs ? TestFSWithWatch.createVirtualServerHost([]) : sys as ServerHost;
         startServer(
             {
                 globalPlugins: findArgumentStringArray("--globalPlugins"),
@@ -71,23 +73,21 @@ namespace ts.server {
             },
             logger,
             cancellationToken,
-            fs
+            fshost
         );
     }
 
     setStackTraceLimit();
-    // TODO: Not sure this is right
-    const fs = findArgument("vfs") ? TestFSWithWatch.createVirtualServerHost([]) : sys as ServerHost;
     // Cannot check process var directory in webworker so has to be typeof check here
     if (typeof process !== "undefined") {
-        start(initializeNodeSystem(), require("os").platform(), fs);
+        start(initializeNodeSystem(), require("os").platform());
     }
     else {
         // Get args from first message
         const listener = (e: any) => {
             removeEventListener("message", listener);
             const args = e.data;
-            start(initializeWebSystem(args), "web", fs);
+            start(initializeWebSystem(args), "web");
         };
         addEventListener("message", listener);
     }

src/tsserver/webServer.ts

@@ -96,13 +96,10 @@ namespace ts.server {
         return [seconds, nanoseconds];
     }
 
-    // TODO: Maybe should leave as ServerHost cast below and declare fs: System
-    // TODO: host is probably still a better name
-    function startWebSession(options: StartSessionOptions, logger: Logger, cancellationToken: ServerCancellationToken, _fs_TODO: ServerHost) {
+    function startWebSession(options: StartSessionOptions, logger: Logger, cancellationToken: ServerCancellationToken, fshost: ServerHost) {
         class WorkerSession extends server.WorkerSession {
             constructor() {
-                // TODO: Not really sure this is the way to do it
-                super(sys as ServerHost, { writeMessage }, options, logger, cancellationToken, hrtime);
+                super(sys as ServerHost, fshost, { writeMessage }, options, logger, cancellationToken, hrtime);
             }
 
             exit() {

src/vfs/virtualFileSystemWithWatch.ts

@@ -337,7 +337,7 @@ namespace ts.TestFSWithWatch {
             }
 
             if (options && options.invokeFileDeleteCreateAsPartInsteadOfChange) {
-                this.removeFileOrFolder(currentEntry, false);
+                this.removeFileOrFolder(currentEntry, /*isRemoveableLeafFolder*/ false);
                 this.ensureFileOrFolder({ path: filePath, content });
             }
             else {
@@ -363,7 +363,7 @@ namespace ts.TestFSWithWatch {
             Debug.assert(!!file);
 
             // Only remove the file
-            this.removeFileOrFolder(file, false, /*isRenaming*/ true);
+            this.removeFileOrFolder(file, /*isRemoveableLeafFolder*/ false, /*isRenaming*/ true);
 
             // Add updated folder with new folder name
             const newFullPath = getNormalizedAbsolutePath(newFileName, this.currentDirectory);
@@ -383,7 +383,7 @@ namespace ts.TestFSWithWatch {
             Debug.assert(!!folder);
 
             // Only remove the folder
-            this.removeFileOrFolder(folder, false, /*isRenaming*/ true);
+            this.removeFileOrFolder(folder, /*isRemoveableLeafFolder*/ false, /*isRenaming*/ true);
 
             // Add updated folder with new folder name
             const newFullPath = getNormalizedAbsolutePath(newFolderName, this.currentDirectory);
@@ -514,11 +514,11 @@ namespace ts.TestFSWithWatch {
                         this.deleteFolder(fsEntry.fullPath, recursive);
                     }
                     else {
-                        this.removeFileOrFolder(fsEntry, false);
+                        this.removeFileOrFolder(fsEntry, /*isRemoveableLeafFolder*/ false);
                     }
                 });
             }
-            this.removeFileOrFolder(currentEntry, false);
+            this.removeFileOrFolder(currentEntry, /*isRemoveableLeafFolder*/ false);
         }
 
         private watchFileWorker(fileName: string, cb: FileWatcherCallback, pollingInterval: PollingInterval) {

src/webServer/webServer.ts

@@ -178,10 +178,10 @@ namespace ts.server {
         serverMode: SessionOptions["serverMode"];
     }
     export class WorkerSession extends Session<{}> {
-        constructor(host: ServerHost, private webHost: HostWithWriteMessage, options: StartSessionOptions, logger: Logger, cancellationToken: ServerCancellationToken, hrtime: SessionOptions["hrtime"]) {
+        constructor(host: ServerHost, fshost: ServerHost, private webHost: HostWithWriteMessage, options: StartSessionOptions, logger: Logger, cancellationToken: ServerCancellationToken, hrtime: SessionOptions["hrtime"]) {
             super({
                 host,
-                fshost: undefined, // TODO: Provide this? Check Sheetal's comments.
+                fshost,
                 cancellationToken,
                 ...options,
                 typingsInstaller: nullTypingsInstaller,