Address first PR comments

Also improve test with a file update

src/harness/virtualFileSystemWithWatch.ts

@@ -289,8 +289,6 @@ interface Array<T> { length: number; [n: number]: T; }`
         readonly screenClears: number[] = [];
         private readonly environmentVariables?: ESMap<string, string>;
         public require: ((initialPath: string, moduleName: string) => RequireResult) | undefined;
-        private readonly tscWatchFile?: string;
-        private readonly tscWatchDirectory?: string;
         private readonly runWithoutRecursiveWatches?: boolean;
         runWithFallbackPolling: boolean;
         public defaultWatchFileKind?: () => WatchFileKind | undefined;
@@ -305,8 +303,8 @@ interface Array<T> { length: number; [n: number]: T; }`
             });
             const { environmentVariables, runWithoutRecursiveWatches, runWithFallbackPolling } = options;
             fileOrFolderOrSymLinkList = fileOrFolderOrSymLinkList.concat(withSafeList ? safeList : []);
-            this.tscWatchFile = environmentVariables && environmentVariables.get("TSC_WATCHFILE");
-            this.tscWatchDirectory = environmentVariables && environmentVariables.get("TSC_WATCHDIRECTORY");
+            const tscWatchFile = environmentVariables && environmentVariables.get("TSC_WATCHFILE");
+            const tscWatchDirectory = environmentVariables && environmentVariables.get("TSC_WATCHDIRECTORY");
             this.runWithoutRecursiveWatches = runWithoutRecursiveWatches;
             this.runWithFallbackPolling = !!runWithFallbackPolling;
             this.environmentVariables = environmentVariables;
@@ -314,7 +312,7 @@ interface Array<T> { length: number; [n: number]: T; }`
                 // We dont have polling watch file
                 // it is essentially fsWatch but lets get that separate from fsWatch and
                 // into watchedFiles for easier testing
-                pollingWatchFile: this.tscWatchFile === Tsc_WatchFile.SingleFileWatcherPerName ?
+                pollingWatchFile: tscWatchFile === Tsc_WatchFile.SingleFileWatcherPerName ?
                     createSingleFileWatcherPerName(
                         this.watchFileWorker.bind(this),
                         this.useCaseSensitiveFileNames
@@ -327,12 +325,12 @@ interface Array<T> { length: number; [n: number]: T; }`
                 fileExists: this.fileExists.bind(this),
                 useCaseSensitiveFileNames: this.useCaseSensitiveFileNames,
                 getCurrentDirectory: this.getCurrentDirectory.bind(this),
-                fsSupportsRecursiveFsWatch: this.tscWatchDirectory ? false : !this.runWithoutRecursiveWatches,
+                fsSupportsRecursiveFsWatch: tscWatchDirectory ? false : !this.runWithoutRecursiveWatches,
                 directoryExists: this.directoryExists.bind(this),
                 getAccessibleSortedChildDirectories: path => this.getDirectories(path),
                 realpath: this.realpath.bind(this),
-                tscWatchFile: this.tscWatchFile,
-                tscWatchDirectory: this.tscWatchDirectory,
+                tscWatchFile: tscWatchFile,
+                tscWatchDirectory: tscWatchDirectory,
                 defaultWatchFileKind: () => this.defaultWatchFileKind?.(),
             });
             this.watchFile = watchFile;
@@ -508,20 +506,6 @@ interface Array<T> { length: number; [n: number]: T; }`
                 );
         }
 
-        readFile(s: string): string | undefined {
-            const fsEntry = this.getRealFile(this.toFullPath(s));
-            return fsEntry ? fsEntry.content : undefined;
-        }
-
-        getFileSize(s: string) {
-            const path = this.toFullPath(s);
-            const entry = this.fs.get(path)!;
-            if (isFsFile(entry)) {
-                return entry.fileSize ? entry.fileSize : entry.content.length;
-            }
-            return undefined!; // TODO: GH#18217
-        }
-
         createHash(s: string): string {
             return `${generateDjb2Hash(s)}-${s}`;
         }

src/server/editorServices.ts

@@ -3698,13 +3698,8 @@ namespace ts.server {
         updateFileSystem(updatedFiles: protocol.FileSystemRequestArgs[] | undefined, deletedFiles?: string[]) {
             Debug.assert(this.fshost instanceof VirtualFS.VirtualServerHost);
             if (updatedFiles) {
-                for (const { file: path, fileContent: content } of updatedFiles) {
-                    if (this.fshost.fileExists(path)) {
-                        this.fshost.modifyFile(path, content);
-                    }
-                    else {
-                        this.fshost.ensureFileOrFolder({ path, content });
-                    }
+                for (const { file, fileContent } of updatedFiles) {
+                    this.fshost.ensureFileOrFolder({ path: file, content: fileContent });
                 }
             }
             if (deletedFiles) {

src/server/project.ts

@@ -1741,7 +1741,7 @@ namespace ts.server {
                 fileExists: this.projectService.fshost.fileExists.bind(this.projectService.fshost),
                 directoryExists: this.projectService.fshost.directoryExists.bind(this.projectService.fshost),
                 realpath: this.projectService.fshost.realpath?.bind(this.projectService.fshost),
-                getCurrentDirectory: this.getCurrentDirectory.bind(this), // TODO: Not sure whether this should be this.projectService.fshost.getCurrentDirectory.bind(this.projectService.fshost)
+                getCurrentDirectory: this.projectService.fshost.getCurrentDirectory.bind(this.projectService.fshost),
                 readFile: this.projectService.fshost.readFile.bind(this.projectService.fshost),
                 getDirectories: this.projectService.fshost.getDirectories.bind(this.projectService.fshost),
                 trace: this.projectService.host.trace?.bind(this.projectService.host),

src/testRunner/unittests/tsserver/updateFileSystem.ts

@@ -85,6 +85,17 @@ ${file.fileContent}`;
                         deleted: [],
                     }
                 }],
+                ["change app.ts content", {
+                    command: protocol.CommandTypes.UpdateFileSystem,
+                    arguments: {
+                        fileSystem: "memfs",
+                        files: [{
+                            file: "/fshost/b/app.ts",
+                            fileContent: "import { xyz } from './file3'; let y = xyz"
+                        }],
+                        deleted: [],
+                    },
+                }],
                 ["delete", {
                     command: protocol.CommandTypes.UpdateFileSystem,
                     arguments:{

src/vfs/virtualFileSystemWithWatch.ts

@@ -209,7 +209,10 @@ namespace ts.VirtualFS {
             if (isFile(fileOrDirectoryOrSymLink)) {
                 const file = this.toFsFile(fileOrDirectoryOrSymLink);
                 // file may already exist when updating existing type declaration file
-                if (!this.fs.get(file.path)) {
+                if (this.fs.get(file.path)) {
+                    this.modifyFile(file.path, file.content);
+                }
+                else {
                     const baseFolder = this.ensureFolder(getDirectoryPath(file.fullPath), ignoreParentWatch);
                     this.addFileOrFolderInFolder(baseFolder, file, ignoreWatchInvokedWithTriggerAsFileCreate);
                 }

tests/baselines/reference/tsserver/updateFileSystem/open-and-close-files.js

@@ -80,7 +80,9 @@ Open files:
 response:{"responseRequired":false}
 request:{"command":"updateFileSystem","arguments":{"fileSystem":"memfs","files":[],"deleted":[]},"seq":4,"type":"request"}
 response:{"response":true,"responseRequired":true}
-request:{"command":"updateFileSystem","arguments":{"fileSystem":"memfs","files":[],"deleted":["/fshost/b/commonFile1.ts"]},"seq":5,"type":"request"}
+request:{"command":"updateFileSystem","arguments":{"fileSystem":"memfs","files":[{"file":"/fshost/b/app.ts","fileContent":"import { xyz } from './file3'; let y = xyz"}],"deleted":[]},"seq":5,"type":"request"}
+response:{"response":true,"responseRequired":true}
+request:{"command":"updateFileSystem","arguments":{"fileSystem":"memfs","files":[],"deleted":["/fshost/b/commonFile1.ts"]},"seq":6,"type":"request"}
 FileWatcher:: Triggered with /fshost/b/commonFile1.ts 2:: WatchInfo: /fshost/b/commonFile1.ts 500 undefined WatchType: Closed Script info
 FileWatcher:: Close:: WatchInfo: /fshost/b/commonFile1.ts 500 undefined WatchType: Closed Script info
 Scheduled: /fshost/b/tsconfig.json
@@ -91,7 +93,7 @@ Scheduled: /fshost/b/tsconfig.json
 Scheduled: *ensureProjectForOpenFiles*
 Elapsed:: *ms DirectoryWatcher:: Triggered with /fshost/b/commonFile1.ts :: WatchInfo: /fshost/b 1 undefined Config: /fshost/b/tsconfig.json WatchType: Wild card directory
 response:{"response":true,"responseRequired":true}
-request:{"command":"close","arguments":{"file":"/fshost/b/app.ts"},"seq":6,"type":"request"}
+request:{"command":"close","arguments":{"file":"/fshost/b/app.ts"},"seq":7,"type":"request"}
 FileWatcher:: Added:: WatchInfo: /fshost/b/app.ts 500 undefined WatchType: Closed Script info
 Project '/fshost/b/tsconfig.json' (Configured)
 	Files (4)

tests/baselines/reference/tsserver/updateFileSystem/open-and-close-files.txt

@@ -39,6 +39,12 @@ interface Array<T> { length: number; [n: number]: T; }
 #### non-delete
 
 
+#### change app.ts content
+//// [/fshost/b/app.ts]
+import { xyz } from './file3'; let y = xyz
+
+
+
 #### delete
 //// [/fshost/b/commonFile1.ts] deleted