fix: jest tests RequestClient.spec.ts

src/types/WriteStream.ts

@@ -1,4 +1,10 @@
-export interface WriteStream {
-  write: (content: string, callback: (err?: Error) => any) => void
-  path: string
+import { WriteStream as FsWriteStream } from 'fs'
+
+export interface WriteStream extends FsWriteStream {
+  write(
+    chunk: any,
+    encoding?: BufferEncoding | ((error: Error | null | undefined) => void),
+    cb?: (error: Error | null | undefined) => void
+  ): boolean
+  path: string | Buffer
 }