Method send

packages/aws-lambda/src/handler.test.ts:43–74

(command: unknown)

  // Methods called by the real S3 transport — minimal surface so the
  // handler's call sites don't need rewriting under test.
  async send(command: unknown): Promise<unknown> {
    const op = command as { input: { Bucket: string; Key: string } } & {
      constructor: { name: string };
    };
    const cmdName = op.constructor?.name ?? "";
    const uri = `s3://${op.input.Bucket}/${op.input.Key}`;
    if (cmdName === "GetObjectCommand") {
      const bytes = this.objects.get(uri) ?? Buffer.alloc(0);
      this.ops.push({ kind: "download", uri, bytes: bytes.length });
      // Mock the AWS SDK stream contract just enough for pipeline() to
      // pump bytes into a write stream.
      const { Readable } = await import("node:stream");
      return { Body: Readable.from([bytes]) };
    }
    if (cmdName === "PutObjectCommand") {
      // Buffer the body so we can record how many bytes were uploaded; the
      // handler's hot path streams from disk, but tests pin the count.
      const body = (command as { input: { Body: NodeJS.ReadableStream | Buffer } }).input.Body;
      let bytes = 0;
      if (Buffer.isBuffer(body)) {
        bytes = body.length;
      } else if (body && typeof (body as NodeJS.ReadableStream).pipe === "function") {
        for await (const chunk of body as NodeJS.ReadableStream) {
          bytes += (chunk as Buffer).length;
        }
      }
      this.ops.push({ kind: "upload", uri, bytes });
      this.objects.set(uri, Buffer.alloc(bytes));
      return {};
    }
    return {};
  }
}

const tmpDirs: string[] = [];