chore(writeStream): refactor function and improve test

src/api/viya/writeStream.ts

@@ -3,13 +3,9 @@ import { WriteStream } from '../../types'
 export const writeStream = async (
   stream: WriteStream,
   content: string
-): Promise<void> => {
-  return new Promise((resolve, reject) => {
-    stream.write(content + '\n', (e) => {
-      if (e) {
-        return reject(e)
-      }
-      return resolve()
-    })
+): Promise<void> =>
+  stream.write(content + '\n', (e) => {
+    if (e) return Promise.reject(e)
+
+    return Promise.resolve()
   })
-}