cfw-bindings-wrangler-bridge/worker/r2/index.js

This bridge makes it possible to interact with **remote** Cloudflare Workers bindings(like KV, D1, etc...) **from anywhere** you want.

// @ts-check
import { parse } from "devalue";
import { hexStringToArrayBuffer, decodeKey } from "./shared.js";

/**
 * @param {any} binding
 * @returns {binding is R2Bucket}
 */
export const isR2Binding = (binding) => binding.constructor.name === "R2Bucket";

/**
 * @param {R2Bucket} R2
 * @param {Request} req
 */
export const handleR2Dispatch = async (R2, req) => {
  const { operation, parameters } = parse(
    req.headers.get("X-BRIDGE-R2-Dispatch") ?? "{}",
    {
      // Date: Handled by default
      Headers: (v) => new Headers(v),
      ArrayBuffer: (v) => hexStringToArrayBuffer(v),
    },
  );

  if (operation === "R2Bucket.list") {
    const [options] = parameters;

    const result = await R2.list(options);

    return Response.json(result);
  }

  if (operation === "R2Bucket.put") {
    const [encodedKey, , options] = parameters;
    const key = decodeKey(encodedKey);
    const value = req.body;

    const result = await R2.put(key, value, options);

    return Response.json(result);
  }

  if (operation === "R2Bucket.get") {
    const [encodedKey, options] = parameters;
    const key = decodeKey(encodedKey);

    const result = await R2.get(key, options);

    // `null`: key does not exists
    if (result === null) return Response.json(null);

    // `R2ObjectBody`: key exists and precondition is met
    if ("body" in result && result.constructor.name === "GetResult")
      return new Response(result.body, {
        headers: { "X-BRIDGE-R2-R2ObjectJSON": JSON.stringify(result) },
      });

    // `R2Object`: key exists but precondition is not met
    return Response.json(result);
  }

  if (operation === "R2Bucket.head") {
    const [encodedKey] = parameters;
    const key = decodeKey(encodedKey);

    const result = await R2.head(key);

    // `null`: key does not exists
    if (result === null) return Response.json(null);

    // `R2Object`: key exists
    return Response.json(result);
  }

  if (operation === "R2Bucket.delete") {
    const [encodedKeys] = parameters;
    const keys =
      typeof encodedKeys === "string"
        ? decodeKey(encodedKeys)
        : encodedKeys.map(/** @param {string} key */ (key) => decodeKey(key));

    await R2.delete(keys);

    return new Response();
  }

  if (operation === "R2Bucket.createMultipartUpload") {
    const [encodedKey, options] = parameters;
    const key = decodeKey(encodedKey);

    const result = await R2.createMultipartUpload(key, options);

    return Response.json(result);
  }

  if (operation === "R2MultipartUpload.uploadPart") {
    const [encodedKey, uploadId, partNumber] = parameters;
    const key = decodeKey(encodedKey);
    const value = req.body ?? "Only for TS, never happens";

    const multipartUpload = R2.resumeMultipartUpload(key, uploadId);
    const result = await multipartUpload.uploadPart(partNumber, value);

    return Response.json(result);
  }

  if (operation === "R2MultipartUpload.abort") {
    const [encodedKey, uploadId] = parameters;
    const key = decodeKey(encodedKey);

    const multipartUpload = R2.resumeMultipartUpload(key, uploadId);
    await multipartUpload.abort();

    return new Response();
  }

  if (operation === "R2MultipartUpload.complete") {
    const [encodedKey, uploadId, uploadedParts] = parameters;
    const key = decodeKey(encodedKey);

    const multipartUpload = R2.resumeMultipartUpload(key, uploadId);
    const result = await multipartUpload.complete(uploadedParts);

    return Response.json(result);
  }

  throw new Error(`${operation}() is not supported.`);
};