Remove most <type> assertions in TS ext (#211648)

These can easily hide typing errors

extensions/typescript-language-features/src/commands/openJsDocLink.ts

@@ -32,8 +32,8 @@ export class OpenJsDocLinkCommand implements Command {
 	public async execute(args: OpenJsDocLinkCommand_Args): Promise<void> {
 		const { line, character } = args.position;
 		const position = new vscode.Position(line, character);
-		await vscode.commands.executeCommand('vscode.open', vscode.Uri.from(args.file), <vscode.TextDocumentShowOptions>{
+		await vscode.commands.executeCommand('vscode.open', vscode.Uri.from(args.file), {
 			selection: new vscode.Range(position, position),
-		});
+		} satisfies vscode.TextDocumentShowOptions);
 	}
 }

extensions/typescript-language-features/src/filesystems/memFs.ts

@@ -8,7 +8,7 @@ import { basename, dirname } from 'path';
 
 export class MemFs implements vscode.FileSystemProvider {
 
-	private readonly root = new FsEntry(
+	private readonly root = new FsDirectoryEntry(
 		new Map(),
 		0,
 		0,
@@ -31,8 +31,11 @@ export class MemFs implements vscode.FileSystemProvider {
 		if (!entry) {
 			throw vscode.FileSystemError.FileNotFound();
 		}
+		if (!(entry instanceof FsDirectoryEntry)) {
+			throw vscode.FileSystemError.FileNotADirectory();
+		}
 
-		return [...entry.contents.entries()].map(([name, entry]) => [name, entry.type]);
+		return Array.from(entry.contents.entries(), ([name, entry]) => [name, entry.type]);
 	}
 
 	readFile(uri: vscode.Uri): Uint8Array {
@@ -43,6 +46,10 @@ export class MemFs implements vscode.FileSystemProvider {
 			throw vscode.FileSystemError.FileNotFound();
 		}
 
+		if (!(entry instanceof FsFileEntry)) {
+			throw vscode.FileSystemError.FileIsADirectory(uri);
+		}
+
 		return entry.data;
 	}
 
@@ -58,12 +65,16 @@ export class MemFs implements vscode.FileSystemProvider {
 		const entry = dirContents.get(basename(uri.path));
 		if (!entry) {
 			if (create) {
-				dirContents.set(fileName, new FsEntry(content, time, time));
+				dirContents.set(fileName, new FsFileEntry(content, time, time));
 				this._emitter.fire([{ type: vscode.FileChangeType.Created, uri }]);
 			} else {
 				throw vscode.FileSystemError.FileNotFound();
 			}
 		} else {
+			if (entry instanceof FsDirectoryEntry) {
+				throw vscode.FileSystemError.FileIsADirectory(uri);
+			}
+
 			if (overwrite) {
 				entry.mtime = time;
 				entry.data = content;
@@ -90,10 +101,10 @@ export class MemFs implements vscode.FileSystemProvider {
 		// console.log('createDirectory', uri.toString());
 		const dir = this.getParent(uri);
 		const now = Date.now() / 1000;
-		dir.contents.set(basename(uri.path), new FsEntry(new Map(), now, now));
+		dir.contents.set(basename(uri.path), new FsDirectoryEntry(new Map(), now, now));
 	}
 
-	private getEntry(uri: vscode.Uri): FsEntry | void {
+	private getEntry(uri: vscode.Uri): FsEntry | undefined {
 		// TODO: have this throw FileNotFound itself?
 		// TODO: support configuring case sensitivity
 		let node: FsEntry = this.root;
@@ -104,13 +115,12 @@ export class MemFs implements vscode.FileSystemProvider {
 				continue;
 			}
 
-			if (node.type !== vscode.FileType.Directory) {
+			if (!(node instanceof FsDirectoryEntry)) {
 				// We're looking at a File or such, so bail.
 				return;
 			}
 
 			const next = node.contents.get(component);
-
 			if (!next) {
 				// not found!
 				return;
@@ -121,11 +131,14 @@ export class MemFs implements vscode.FileSystemProvider {
 		return node;
 	}
 
-	private getParent(uri: vscode.Uri) {
+	private getParent(uri: vscode.Uri): FsDirectoryEntry {
 		const dir = this.getEntry(uri.with({ path: dirname(uri.path) }));
 		if (!dir) {
 			throw vscode.FileSystemError.FileNotFound();
 		}
+		if (!(dir instanceof FsDirectoryEntry)) {
+			throw vscode.FileSystemError.FileNotADirectory();
+		}
 		return dir;
 	}
 
@@ -153,46 +166,32 @@ export class MemFs implements vscode.FileSystemProvider {
 	}
 }
 
-class FsEntry {
-	get type(): vscode.FileType {
-		if (this._data instanceof Uint8Array) {
-			return vscode.FileType.File;
-		} else {
-			return vscode.FileType.Directory;
-		}
-	}
+class FsFileEntry {
+	readonly type = vscode.FileType.File;
 
 	get size(): number {
-		if (this.type === vscode.FileType.Directory) {
-			return [...this.contents.values()].reduce((acc: number, entry: FsEntry) => acc + entry.size, 0);
-		} else {
-			return this.data.length;
-		}
+		return this.data.length;
 	}
 
 	constructor(
-		private _data: Uint8Array | Map<string, FsEntry>,
-		public ctime: number,
+		public data: Uint8Array,
+		public readonly ctime: number,
 		public mtime: number,
 	) { }
-
-	get data() {
-		if (this.type === vscode.FileType.Directory) {
-			throw vscode.FileSystemError.FileIsADirectory;
-		}
-		return <Uint8Array>this._data;
-	}
-	set data(val: Uint8Array) {
-		if (this.type === vscode.FileType.Directory) {
-			throw vscode.FileSystemError.FileIsADirectory;
-		}
-		this._data = val;
-	}
-
-	get contents() {
-		if (this.type !== vscode.FileType.Directory) {
-			throw vscode.FileSystemError.FileNotADirectory;
-		}
-		return <Map<string, FsEntry>>this._data;
-	}
 }
+
+class FsDirectoryEntry {
+	readonly type = vscode.FileType.Directory;
+
+	get size(): number {
+		return [...this.contents.values()].reduce((acc: number, entry: FsEntry) => acc + entry.size, 0);
+	}
+
+	constructor(
+		public readonly contents: Map<string, FsEntry>,
+		public readonly ctime: number,
+		public readonly mtime: number,
+	) { }
+}
+
+type FsEntry = FsFileEntry | FsDirectoryEntry;

extensions/typescript-language-features/src/utils/arrays.ts

@@ -20,5 +20,5 @@ export function equals<T>(
 }
 
 export function coalesce<T>(array: ReadonlyArray<T | undefined>): T[] {
-	return <T[]>array.filter(e => !!e);
+	return array.filter((e): e is T => !!e);
 }