Add createReadStream/createWriteStream to FileSystem in node-core-library and update consumers to use FileSystem instead of fs directly

Agent-Logs-Url: https://github.com/microsoft/rushstack/sessions/5ad20d4d-c9a4-4855-bb13-8dd9e2c1350b

Co-authored-by: iclanton <5010588+iclanton@users.noreply.github.com>

Author: Copilot

common/changes/@rushstack/node-core-library/copilot-stream-cache-entry-for-http-plugin_2026-04-05-04-27.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Add createReadStream() and createWriteStream() APIs, along with FileSystemReadStream and FileSystemWriteStream type aliases",
+      "type": "minor",
+      "packageName": "@rushstack/node-core-library"
+    }
+  ],
+  "packageName": "@rushstack/node-core-library",
+  "email": "198982749+Copilot@users.noreply.github.com"
+}

common/reviews/api/node-core-library.api.md

@@ -166,12 +166,14 @@ export class FileSystem {
     static copyFilesAsync(options: IFileSystemCopyFilesAsyncOptions): Promise<void>;
     static createHardLink(options: IFileSystemCreateLinkOptions): void;
     static createHardLinkAsync(options: IFileSystemCreateLinkOptions): Promise<void>;
+    static createReadStream(filePath: string): FileSystemReadStream;
     static createSymbolicLinkFile(options: IFileSystemCreateLinkOptions): void;
     static createSymbolicLinkFileAsync(options: IFileSystemCreateLinkOptions): Promise<void>;
     static createSymbolicLinkFolder(options: IFileSystemCreateLinkOptions): void;
     static createSymbolicLinkFolderAsync(options: IFileSystemCreateLinkOptions): Promise<void>;
     static createSymbolicLinkJunction(options: IFileSystemCreateLinkOptions): void;
     static createSymbolicLinkJunctionAsync(options: IFileSystemCreateLinkOptions): Promise<void>;
+    static createWriteStream(filePath: string): FileSystemWriteStream;
     static deleteFile(filePath: string, options?: IFileSystemDeleteFileOptions): void;
     static deleteFileAsync(filePath: string, options?: IFileSystemDeleteFileOptions): Promise<void>;
     static deleteFolder(folderPath: string): void;
@@ -225,9 +227,15 @@ export type FileSystemCopyFilesAsyncFilter = (sourcePath: string, destinationPat
 // @public
 export type FileSystemCopyFilesFilter = (sourcePath: string, destinationPath: string) => boolean;
 
+// @public
+export type FileSystemReadStream = fs.ReadStream;
+
 // @public
 export type FileSystemStats = fs.Stats;
 
+// @public
+export type FileSystemWriteStream = fs.WriteStream;
+
 // @public
 export class FileWriter {
     close(): void;

libraries/node-core-library/src/FileSystem.ts

@@ -28,6 +28,24 @@ export type FileSystemStats = fs.Stats;
  */
 export type FolderItem = fs.Dirent;
 
+/**
+ * An alias for the Node.js `fs.ReadStream` object.
+ *
+ * @remarks
+ * This avoids the need to import the `fs` package when using the {@link FileSystem} API.
+ * @public
+ */
+export type FileSystemReadStream = fs.ReadStream;
+
+/**
+ * An alias for the Node.js `fs.WriteStream` object.
+ *
+ * @remarks
+ * This avoids the need to import the `fs` package when using the {@link FileSystem} API.
+ * @public
+ */
+export type FileSystemWriteStream = fs.WriteStream;
+
 // The PosixModeBits are intended to be used with bitwise operations.
 /* eslint-disable no-bitwise */
 
@@ -1237,6 +1255,28 @@ export class FileSystem {
     });
   }
 
+  /**
+   * Creates a readable stream for an existing file.
+   * Behind the scenes it uses `fs.createReadStream()`.
+   *
+   * @param filePath - The path to the file. The path may be absolute or relative.
+   * @returns A new readable stream for the file.
+   */
+  public static createReadStream(filePath: string): FileSystemReadStream {
+    return fs.createReadStream(filePath);
+  }
+
+  /**
+   * Creates a writable stream for writing to a file.
+   * Behind the scenes it uses `fs.createWriteStream()`.
+   *
+   * @param filePath - The path to the file. The path may be absolute or relative.
+   * @returns A new writable stream for the file.
+   */
+  public static createWriteStream(filePath: string): FileSystemWriteStream {
+    return fs.createWriteStream(filePath);
+  }
+
   // ===============
   // LINK OPERATIONS
   // ===============

libraries/node-core-library/src/index.ts

@@ -52,6 +52,8 @@ export {
   FileSystem,
   type FileSystemCopyFilesAsyncFilter,
   type FileSystemCopyFilesFilter,
+  type FileSystemReadStream,
+  type FileSystemWriteStream,
   type FolderItem,
   type FileSystemStats,
   type IFileSystemCopyFileBaseOptions,