Delete incomplete uploads with unstable_createFileUploadHandler

[krzysdz]

Upload handler created with unstable_createFileUploadHandler leaves incomplete files on disk if the request is aborted. Because the filename may not be known until the Promise from unstable_parseMultipartFormData resolves, it is impossible to delete the file in action if the ECONNRESET error is caught.

The handler is already able to remove some failed uploads (when the allowed size is exceeded, see the fragment below) and could be modified to set deleteFile = true if any error occurs.

remix/packages/remix-node/upload/fileUploadHandler.ts

Lines 135 to 151 in 32300ec

	try {
	for await (let chunk of data) {
	size += chunk.byteLength;
	if (size > maxPartSize) {
	deleteFile = true;
	throw new MaxPartSizeExceededError(name, maxPartSize);
	}
	writeFileStream.write(chunk);
	}
	} finally {
	writeFileStream.end();
	await promisify(finished)(writeFileStream);
	if (deleteFile) {
	await rm(filepath).catch(() => {});
	}
	}

Suggestions

My idea is to add a catch block before finally, set deleteFile and rethrow. The finally will still be executed, clean up and the error will be rethrown to handle up in the stack.

Special handling for ECONNRESET

    try {
      // ... (no change)
    } catch (error) {
      if ((error as any).code === "ECONNRESET") {
        deleteFile = true;
      }
      throw error;
    } finally {
      // ... (no change)
    }

Delete file on any error

    try {
      for await (let chunk of data) {
        size += chunk.byteLength;
        if (size > maxPartSize) {
          // The `catch` block will set `deleteFile = true`, so it's not necessary here
          throw new MaxPartSizeExceededError(name, maxPartSize);
        }
        writeFileStream.write(chunk);
      }
    } catch (error) {
      deleteFile = true;
      throw error;
    } finally {
      // ... (no change)
    }