fix(NODE-4788)!: use implementer Writable methods for GridFSBucketWriteStream (#3808)

Co-authored-by: Durran Jordan <[email protected]>

Author: nbbeeken

src/gridfs/download.ts

@@ -78,35 +78,15 @@ export interface GridFSBucketReadStreamPrivate {
  * Do not instantiate this class directly. Use `openDownloadStream()` instead.
  * @public
  */
-export class GridFSBucketReadStream extends Readable implements NodeJS.ReadableStream {
+export class GridFSBucketReadStream extends Readable {
   /** @internal */
   s: GridFSBucketReadStreamPrivate;
 
-  /**
-   * An error occurred
-   * @event
-   */
-  static readonly ERROR = 'error' as const;
   /**
    * Fires when the stream loaded the file document corresponding to the provided id.
    * @event
    */
   static readonly FILE = 'file' as const;
-  /**
-   * Emitted when a chunk of data is available to be consumed.
-   * @event
-   */
-  static readonly DATA = 'data' as const;
-  /**
-   * Fired when the stream is exhausted (no more data events).
-   * @event
-   */
-  static readonly END = 'end' as const;
-  /**
-   * Fired when the stream is exhausted and the underlying cursor is killed
-   * @event
-   */
-  static readonly CLOSE = 'close' as const;
 
   /**
    * @param chunks - Handle for chunks collection
@@ -122,7 +102,7 @@ export class GridFSBucketReadStream extends Readable implements NodeJS.ReadableS
     filter: Document,
     options?: GridFSBucketReadStreamOptions
   ) {
-    super();
+    super({ emitClose: true });
     this.s = {
       bytesToTrim: 0,
       bytesToSkip: 0,
@@ -185,20 +165,8 @@ export class GridFSBucketReadStream extends Readable implements NodeJS.ReadableS
    */
   async abort(): Promise<void> {
     this.push(null);
-    this.destroyed = true;
-    if (this.s.cursor) {
-      try {
-        await this.s.cursor.close();
-      } finally {
-        this.emit(GridFSBucketReadStream.CLOSE);
-      }
-    } else {
-      if (!this.s.init) {
-        // If not initialized, fire close event because we will never
-        // get a cursor
-        this.emit(GridFSBucketReadStream.CLOSE);
-      }
-    }
+    this.destroy();
+    await this.s.cursor?.close();
   }
 }
 
@@ -221,19 +189,15 @@ function doRead(stream: GridFSBucketReadStream): void {
       return;
     }
     if (error) {
-      stream.emit(GridFSBucketReadStream.ERROR, error);
+      stream.destroy(error);
       return;
     }
     if (!doc) {
       stream.push(null);
 
       stream.s.cursor?.close().then(
-        () => {
-          stream.emit(GridFSBucketReadStream.CLOSE);
-        },
-        error => {
-          stream.emit(GridFSBucketReadStream.ERROR, error);
-        }
+        () => null,
+        error => stream.destroy(error)
       );
       return;
     }
@@ -244,17 +208,15 @@ function doRead(stream: GridFSBucketReadStream): void {
     const expectedN = stream.s.expected++;
     const expectedLength = Math.min(stream.s.file.chunkSize, bytesRemaining);
     if (doc.n > expectedN) {
-      return stream.emit(
-        GridFSBucketReadStream.ERROR,
+      return stream.destroy(
         new MongoGridFSChunkError(
           `ChunkIsMissing: Got unexpected n: ${doc.n}, expected: ${expectedN}`
         )
       );
     }
 
     if (doc.n < expectedN) {
-      return stream.emit(
-        GridFSBucketReadStream.ERROR,
+      return stream.destroy(
         new MongoGridFSChunkError(`ExtraChunk: Got unexpected n: ${doc.n}, expected: ${expectedN}`)
       );
     }
@@ -263,16 +225,14 @@ function doRead(stream: GridFSBucketReadStream): void {
 
     if (buf.byteLength !== expectedLength) {
       if (bytesRemaining <= 0) {
-        return stream.emit(
-          GridFSBucketReadStream.ERROR,
+        return stream.destroy(
           new MongoGridFSChunkError(
             `ExtraChunk: Got unexpected n: ${doc.n}, expected file length ${stream.s.file.length} bytes but already read ${stream.s.bytesRead} bytes`
           )
         );
       }
 
-      return stream.emit(
-        GridFSBucketReadStream.ERROR,
+      return stream.destroy(
         new MongoGridFSChunkError(
           `ChunkIsWrongSize: Got unexpected length: ${buf.byteLength}, expected: ${expectedLength}`
         )
@@ -332,7 +292,7 @@ function init(stream: GridFSBucketReadStream): void {
     doc
   }: { error: Error; doc: null } | { error: null; doc: any }) => {
     if (error) {
-      return stream.emit(GridFSBucketReadStream.ERROR, error);
+      return stream.destroy(error);
     }
 
     if (!doc) {
@@ -343,7 +303,7 @@ function init(stream: GridFSBucketReadStream): void {
       // TODO(NODE-3483)
       const err = new MongoRuntimeError(errmsg);
       err.code = 'ENOENT'; // TODO: NODE-3338 set property as part of constructor
-      return stream.emit(GridFSBucketReadStream.ERROR, err);
+      return stream.destroy(err);
     }
 
     // If document is empty, kill the stream immediately and don't
@@ -357,14 +317,14 @@ function init(stream: GridFSBucketReadStream): void {
       // If user destroys the stream before we have a cursor, wait
       // until the query is done to say we're 'closed' because we can't
       // cancel a query.
-      stream.emit(GridFSBucketReadStream.CLOSE);
+      stream.destroy();
       return;
     }
 
     try {
       stream.s.bytesToSkip = handleStartOption(stream, doc, stream.s.options);
     } catch (error) {
-      return stream.emit(GridFSBucketReadStream.ERROR, error);
+      return stream.destroy(error);
     }
 
     const filter: Document = { files_id: doc._id };
@@ -390,7 +350,7 @@ function init(stream: GridFSBucketReadStream): void {
     try {
       stream.s.bytesToTrim = handleEndOption(stream, doc, stream.s.cursor, stream.s.options);
     } catch (error) {
-      return stream.emit(GridFSBucketReadStream.ERROR, error);
+      return stream.destroy(error);
     }
 
     stream.emit(GridFSBucketReadStream.FILE, doc);