processRequest.test.mjs

// @ts-check

import "./test/polyfillFile.mjs";
import "./test/polyfillPromiseWithResolvers.mjs";

import {
  deepStrictEqual,
  notStrictEqual,
  ok,
  rejects,
  strictEqual,
  throws,
} from "node:assert";
import { createServer } from "node:http";
import { getDefaultHighWaterMark } from "node:stream";
import { text } from "node:stream/consumers";
import { describe, it } from "node:test";

import { listen } from "async-listen";
import { ReadStream } from "fs-capacitor";

import processRequest from "./processRequest.mjs";
import abortingMultipartRequest from "./test/abortingMultipartRequest.mjs";
import Upload from "./Upload.mjs";

describe(
  "Function `processRequest`.",
  {
    concurrency: true,
  },
  () => {
    it("No files.", async () => {
      let serverError;

      const operation = { variables: { a: true } };
      const server = createServer(async (request, response) => {
        try {
          deepStrictEqual(await processRequest(request, response), operation);
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append("operations", JSON.stringify(operation));
        body.append("map", "{}");

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("A single file, default `createReadStream` options, file name chars `latin1`.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     file: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          ok(operation.variables.file instanceof Upload);

          const upload = await operation.variables.file.promise;

          strictEqual(upload.filename, "a.txt");
          strictEqual(upload.mimetype, "text/plain");
          strictEqual(upload.encoding, "7bit");

          const stream = upload.createReadStream();

          ok(stream instanceof ReadStream);
          strictEqual(stream.readableEncoding, null);
          strictEqual(
            stream.readableHighWaterMark,
            getDefaultHighWaterMark(false),
          );
          strictEqual(await text(stream), "a");
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("A single file, default `createReadStream` options, file name chars non `latin1`.", async () => {
      const fileName = "你好.txt";

      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     file: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          ok(operation.variables.file instanceof Upload);

          const upload = await operation.variables.file.promise;

          strictEqual(upload.filename, fileName);
          strictEqual(upload.mimetype, "text/plain");
          strictEqual(upload.encoding, "7bit");

          const stream = upload.createReadStream();

          ok(stream instanceof ReadStream);
          strictEqual(stream.readableEncoding, null);
          strictEqual(
            stream.readableHighWaterMark,
            getDefaultHighWaterMark(false),
          );
          strictEqual(await text(stream), "a");
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append("1", new File(["a"], fileName, { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("A single file and custom `createReadStream` options.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     file: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          ok(operation.variables.file instanceof Upload);

          const upload = await operation.variables.file.promise;

          strictEqual(upload.filename, "a.txt");
          strictEqual(upload.mimetype, "text/plain");
          strictEqual(upload.encoding, "7bit");

          const encoding = "base64";
          const highWaterMark = 100;
          const stream = upload.createReadStream({ encoding, highWaterMark });

          ok(stream instanceof ReadStream);
          strictEqual(stream.readableEncoding, encoding);
          strictEqual(stream.readableHighWaterMark, highWaterMark);
          strictEqual(await text(stream), Buffer.from("a").toString(encoding));
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("A single file, batched.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operations =
            /**
             * @type {Array<{
             *   variables: {
             *     file: Upload,
             *   },
             * }>}
             */
            (await processRequest(request, response));

          ok(operations[0].variables.file instanceof Upload);

          const uploadA = await operations[0].variables.file.promise;

          strictEqual(uploadA.filename, "a.txt");
          strictEqual(uploadA.mimetype, "text/plain");
          strictEqual(uploadA.encoding, "7bit");

          const streamA = uploadA.createReadStream();

          ok(streamA instanceof ReadStream);
          strictEqual(await text(streamA), "a");

          ok(operations[1].variables.file instanceof Upload);

          const uploadB = await operations[1].variables.file.promise;

          strictEqual(uploadB.filename, "b.txt");
          strictEqual(uploadB.mimetype, "text/plain");
          strictEqual(uploadB.encoding, "7bit");

          const streamB = uploadB.createReadStream();

          ok(streamB instanceof ReadStream);
          strictEqual(await text(streamB), "b");
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify([
            { variables: { file: null } },
            { variables: { file: null } },
          ]),
        );
        body.append(
          "map",
          JSON.stringify({ 1: ["0.variables.file"], 2: ["1.variables.file"] }),
        );
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        body.append("2", new File(["b"], "b.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Deduped files.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     files: Array<Upload>,
             *   },
             * }}
             */
            (await processRequest(request, response));

          ok(operation.variables.files[0] instanceof Upload);
          ok(operation.variables.files[1] instanceof Upload);
          strictEqual(
            operation.variables.files[0],
            operation.variables.files[1],
          );

          const [upload1, upload2] = await Promise.all([
            operation.variables.files[0].promise,
            operation.variables.files[1].promise,
          ]);

          strictEqual(upload1, upload2);
          strictEqual(upload1.filename, "a.txt");
          strictEqual(upload1.mimetype, "text/plain");
          strictEqual(upload1.encoding, "7bit");

          const stream1 = upload1.createReadStream();
          const stream2 = upload2.createReadStream();

          notStrictEqual(stream1, stream2);
          ok(stream1 instanceof ReadStream);
          ok(stream2 instanceof ReadStream);

          const [content1, content2] = await Promise.all([
            text(stream1),
            text(stream2),
          ]);

          strictEqual(content1, "a");
          strictEqual(content2, "a");
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { files: [null, null] } }),
        );
        body.append(
          "map",
          JSON.stringify({ 1: ["variables.files.0", "variables.files.1"] }),
        );
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Unconsumed uploads.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     fileA: Upload,
             *     fileB: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          ok(operation.variables.fileB instanceof Upload);

          const uploadB = await operation.variables.fileB.promise;
          const streamB = uploadB.createReadStream();

          await text(streamB);
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { fileA: null, fileB: null } }),
        );
        body.append(
          "map",
          JSON.stringify({ 1: ["variables.fileA"], 2: ["variables.fileB"] }),
        );
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        body.append("2", new File(["b"], "b.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("An extraneous multipart form field file.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     file: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          ok(operation.variables.file instanceof Upload);

          const upload = await operation.variables.file.promise;

          strictEqual(upload.filename, "a.txt");
          strictEqual(upload.mimetype, "text/plain");
          strictEqual(upload.encoding, "7bit");

          const stream = upload.createReadStream();

          ok(stream instanceof ReadStream);
          strictEqual(await text(stream), "a");
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        body.append("2", new File(["b"], "b.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("A missing multipart form field file.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     file: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          ok(operation.variables.file instanceof Upload);
          await rejects(operation.variables.file.promise, {
            name: "BadRequestError",
            message: "File missing in the request.",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Option `maxFiles`.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response, { maxFiles: 1 }), {
            name: "PayloadTooLargeError",
            message: "1 max file uploads exceeded.",
            status: 413,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { files: [null, null] } }),
        );
        body.append(
          "map",
          JSON.stringify({
            1: ["variables.files.0"],
            2: ["variables.files.1"],
          }),
        );
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        body.append("2", new File(["b"], "b.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Option `maxFiles` and an interspersed extraneous file.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     files: Array<Upload>,
             *   },
             * }}
             */
            (await processRequest(request, response, { maxFiles: 2 }));

          ok(operation.variables.files[0] instanceof Upload);

          const uploadA = await operation.variables.files[0].promise;

          strictEqual(uploadA.filename, "a.txt");
          strictEqual(uploadA.mimetype, "text/plain");
          strictEqual(uploadA.encoding, "7bit");

          const streamA = uploadA.createReadStream();

          ok(streamA instanceof ReadStream);
          strictEqual(await text(streamA), "a");
          ok(operation.variables.files[1] instanceof Upload);
          await rejects(operation.variables.files[1].promise, {
            name: "PayloadTooLargeError",
            message: "2 max file uploads exceeded.",
            status: 413,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { files: [null, null] } }),
        );
        body.append(
          "map",
          JSON.stringify({
            1: ["variables.files.0"],
            2: ["variables.files.1"],
          }),
        );
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        body.append(
          "extraneous",
          new File(["c"], "c.txt", { type: "text/plain" }),
        );
        body.append("2", new File(["b"], "b.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Option `maxFileSize`.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          const operation =
            /**
             * @type {{
             *   variables: {
             *     files: Array<Upload>,
             *   },
             * }}
             */
            (
              await processRequest(request, response, {
                // Todo: Change this back to 1 once this `busboy` bug is fixed:
                // https://github.com/mscdex/busboy/issues/297
                maxFileSize: 2,
              })
            );

          ok(operation.variables.files[0] instanceof Upload);

          const { createReadStream } =
            await operation.variables.files[0].promise;

          throws(
            () => {
              createReadStream();
            },
            {
              name: "PayloadTooLargeError",
              message: "File truncated as it exceeds the 2 byte size limit.",
              status: 413,
              expose: true,
            },
          );

          ok(operation.variables.files[0] instanceof Upload);

          const uploadB = await operation.variables.files[1].promise;

          strictEqual(uploadB.filename, "b.txt");
          strictEqual(uploadB.mimetype, "text/plain");
          strictEqual(uploadB.encoding, "7bit");

          const streamB = uploadB.createReadStream();

          ok(streamB instanceof ReadStream);
          strictEqual(await text(streamB), "b");
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { files: [null, null] } }),
        );
        body.append(
          "map",
          JSON.stringify({
            1: ["variables.files.0"],
            2: ["variables.files.1"],
          }),
        );
        body.append("1", new File(["aa"], "a.txt", { type: "text/plain" }));
        body.append("2", new File(["b"], "b.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Option `maxFieldSize`.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(
            processRequest(request, response, { maxFieldSize: 1 }),
            {
              name: "PayloadTooLargeError",
              message:
                "The ‘operations’ multipart field value exceeds the 1 byte size limit.",
              status: 413,
              expose: true,
            },
          );
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("An aborted request and immediate stream creation.", async () => {
      let serverError;

      // In other tests a fetch request can be awaited that resolves once the
      // request, tests and response are done. Because this test aborts a
      // request part way through, the server request handler must be manually
      // awaited or else the test will resolve and the process will exit before
      // it’s done.

      /** @type {PromiseWithResolvers<void>} */
      const done = Promise.withResolvers();

      // The request must be aborted after it has been received by the server
      // request handler, or else Node.js won’t run the handler.

      /** @type {PromiseWithResolvers<void>} */
      const requestReceived = Promise.withResolvers();

      const server = createServer(async (request, response) => {
        try {
          requestReceived.resolve();

          const operation =
            /**
             * @type {{
             *   variables: {
             *     fileA: Upload,
             *     fileB: Upload,
             *     fileC: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          const testUploadA = async () => {
            ok(operation.variables.fileA instanceof Upload);

            const upload = await operation.variables.fileA.promise;

            strictEqual(upload.filename, "a.txt");
            strictEqual(upload.mimetype, "text/plain");
            strictEqual(upload.encoding, "7bit");

            const stream = upload.createReadStream();

            ok(stream instanceof ReadStream);
            strictEqual(await text(stream), "a");
          };

          const testUploadB = async () => {
            ok(operation.variables.fileB instanceof Upload);

            const upload = await operation.variables.fileB.promise;

            strictEqual(upload.filename, "b.txt");
            strictEqual(upload.mimetype, "text/plain");
            strictEqual(upload.encoding, "7bit");

            const stream = upload.createReadStream();

            ok(stream instanceof ReadStream);
            await rejects(
              new Promise((resolve, reject) => {
                stream.once("error", reject).once("end", resolve).resume();
              }),
              {
                name: "BadRequestError",
                message:
                  "Request disconnected during file upload stream parsing.",
                status: 499,
                expose: true,
              },
            );
          };

          const testUploadC = async () => {
            ok(operation.variables.fileC instanceof Upload);
            await rejects(operation.variables.fileC.promise, {
              name: "BadRequestError",
              message:
                "Request disconnected during file upload stream parsing.",
              status: 499,
              expose: true,
            });
          };

          await Promise.all([testUploadA(), testUploadB(), testUploadC()]);
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
          done.resolve();
        }
      });

      const url = await listen(server);

      try {
        const abortMarker = "⛔";
        const formData = new FormData();

        formData.append(
          "operations",
          JSON.stringify({
            variables: { fileA: null, fileB: null, fileC: null },
          }),
        );
        formData.append(
          "map",
          JSON.stringify({
            1: ["variables.fileA"],
            2: ["variables.fileB"],
            3: ["variables.fileC"],
          }),
        );
        formData.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        formData.append(
          "2",
          new File(
            [
              // Will arrive in multiple chunks as the TCP max packet size is
              // 64000 bytes and the default Node.js fs stream buffer is 65536
              // bytes.
              `${"b".repeat(70000)}${abortMarker}${"b".repeat(10)}`,
            ],
            "b.txt",
            { type: "text/plain" },
          ),
        );
        formData.append("3", new File(["c"], "c.txt", { type: "text/plain" }));

        await abortingMultipartRequest(
          url,
          formData,
          abortMarker,
          requestReceived.promise,
        );

        await done.promise;

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("An aborted request and delayed stream creation.", async () => {
      let serverError;

      // In other tests a fetch request can be awaited that resolves once the
      // request, tests and response are done. Because this test aborts a
      // request part way through, the server request handler must be manually
      // awaited or else the test will resolve and the process will exit before
      // it’s done.

      /** @type {PromiseWithResolvers<void>} */
      const done = Promise.withResolvers();

      // The request must be aborted after it has been received by the server
      // request handler, or else Node.js won’t run the handler.

      /** @type {PromiseWithResolvers<void>} */
      const requestReceived = Promise.withResolvers();

      const server = createServer(async (request, response) => {
        try {
          requestReceived.resolve();

          const operation =
            /**
             * @type {{
             *   variables: {
             *     fileA: Upload,
             *     fileB: Upload,
             *     fileC: Upload,
             *   },
             * }}
             */
            (await processRequest(request, response));

          // Wait for the request parsing to finish.
          await new Promise((resolve) => {
            request.once("close", resolve);
          });

          const testUploadA = async () => {
            ok(operation.variables.fileA instanceof Upload);

            const upload = await operation.variables.fileA.promise;

            strictEqual(upload.filename, "a.txt");
            strictEqual(upload.mimetype, "text/plain");
            strictEqual(upload.encoding, "7bit");

            throws(() => upload.createReadStream(), {
              name: "BadRequestError",
              message:
                "Request disconnected during file upload stream parsing.",
              status: 499,
              expose: true,
            });
          };

          const testUploadB = async () => {
            ok(operation.variables.fileB instanceof Upload);

            const upload = await operation.variables.fileB.promise;

            strictEqual(upload.filename, "b.txt");
            strictEqual(upload.mimetype, "text/plain");
            strictEqual(upload.encoding, "7bit");
            throws(() => upload.createReadStream(), {
              name: "BadRequestError",
              message:
                "Request disconnected during file upload stream parsing.",
              status: 499,
              expose: true,
            });
          };

          const testUploadC = async () => {
            ok(operation.variables.fileC instanceof Upload);
            await rejects(operation.variables.fileC.promise, {
              name: "BadRequestError",
              message:
                "Request disconnected during file upload stream parsing.",
              status: 499,
              expose: true,
            });
          };

          await Promise.all([testUploadA(), testUploadB(), testUploadC()]);
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
          done.resolve();
        }
      });

      const url = await listen(server);

      try {
        const abortMarker = "⛔";
        const formData = new FormData();

        formData.append(
          "operations",
          JSON.stringify({
            variables: { fileA: null, fileB: null, fileC: null },
          }),
        );
        formData.append(
          "map",
          JSON.stringify({
            1: ["variables.fileA"],
            2: ["variables.fileB"],
            3: ["variables.fileC"],
          }),
        );
        formData.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        formData.append(
          "2",
          new File(
            [
              // Will arrive in multiple chunks as the TCP max packet size is
              // 64000 bytes and the default Node.js fs stream buffer is 65536
              // bytes.
              `${"b".repeat(70000)}${abortMarker}${"b".repeat(10)}`,
            ],
            "b.txt",
            { type: "text/plain" },
          ),
        );
        formData.append("3", new File(["c"], "c.txt", { type: "text/plain" }));

        await abortingMultipartRequest(
          url,
          formData,
          abortMarker,
          requestReceived.promise,
        );

        await done.promise;

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Multipart form field `map` misordered before `operations`.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Misordered multipart fields; ‘map’ should follow ‘operations’ (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Multipart form field file misordered before `map`.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Misordered multipart fields; files should follow ‘map’ (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Multipart form fields `map` and file missing.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Missing multipart field ‘map’ (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Multipart form fields `operations`, `map` and file missing.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Missing multipart field ‘operations’ (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        await fetch(url, {
          method: "POST",
          body: new FormData(),
        });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Invalid multipart form field `operations` JSON and a small file.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Invalid JSON in the ‘operations’ multipart field (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append("operations", "{ x }");
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Invalid multipart form field `operations` JSON and a large file.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Invalid JSON in the ‘operations’ multipart field (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append("operations", "{ x }");
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append(
          "1",
          new File(
            [
              // Will arrive in multiple chunks as the TCP max packet size is
              // 64000 bytes and the default Node.js fs stream buffer is 65536
              // bytes.
              "a".repeat(70000),
            ],
            "a.txt",
            { type: "text/plain" },
          ),
        );

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    for (const [type, value] of [
      ["null", null],
      ["boolean", true],
      ["string", ""],
    ])
      it(`Invalid multipart form field \`operations\` type, ${type}.`, async () => {
        let serverError;

        const server = createServer(async (request, response) => {
          try {
            await rejects(processRequest(request, response), {
              name: "BadRequestError",
              message:
                "Invalid type for the ‘operations’ multipart field (https://github.com/jaydenseric/graphql-multipart-request-spec).",
              status: 400,
              expose: true,
            });
          } catch (error) {
            serverError = error;
          } finally {
            response.end();
          }
        });

        const url = await listen(server);

        try {
          const body = new FormData();

          body.append("operations", JSON.stringify(value));
          body.append("map", JSON.stringify({ 1: ["variables.file"] }));
          body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

          await fetch(url, { method: "POST", body });

          if (serverError) throw serverError;
        } finally {
          server.close();
        }
      });

    it("Invalid multipart form field `map` JSON.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Invalid JSON in the ‘map’ multipart field (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", "{ x }");
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    for (const [type, value] of [
      ["null", null],
      ["array", []],
      ["boolean", true],
      ["string", ""],
    ])
      it(`Invalid multipart form field \`map\` type, ${type}.`, async () => {
        let serverError;

        const server = createServer(async (request, response) => {
          try {
            await rejects(processRequest(request, response), {
              name: "BadRequestError",
              message:
                "Invalid type for the ‘map’ multipart field (https://github.com/jaydenseric/graphql-multipart-request-spec).",
              status: 400,
              expose: true,
            });
          } catch (error) {
            serverError = error;
          } finally {
            response.end();
          }
        });

        const url = await listen(server);

        try {
          const body = new FormData();

          body.append(
            "operations",
            JSON.stringify({ variables: { file: null } }),
          );
          body.append("map", JSON.stringify(value));
          body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

          await fetch(url, { method: "POST", body });

          if (serverError) throw serverError;
        } finally {
          server.close();
        }
      });

    it("Invalid multipart form field `map` entry type.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Invalid type for the ‘map’ multipart field entry key ‘1’ array (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: null }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Invalid multipart form field `map` entry array item type.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Invalid type for the ‘map’ multipart field entry key ‘1’ array index ‘0’ value (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append(
          "operations",
          JSON.stringify({ variables: { file: null } }),
        );
        body.append("map", JSON.stringify({ 1: [null] }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("Invalid multipart form field `map` entry array item object path.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "BadRequestError",
            message:
              "Invalid object path for the ‘map’ multipart field entry key ‘1’ array index ‘0’ value ‘variables.file’ (https://github.com/jaydenseric/graphql-multipart-request-spec).",
            status: 400,
            expose: true,
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const body = new FormData();

        body.append("operations", JSON.stringify({ variables: "" }));
        body.append("map", JSON.stringify({ 1: ["variables.file"] }));
        body.append("1", new File(["a"], "a.txt", { type: "text/plain" }));

        await fetch(url, { method: "POST", body });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("An unparsable multipart request.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "Error",
            message: "Unexpected end of form",
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const boundary = "abcde";

        await fetch(url, {
          method: "POST",
          headers: {
            "Content-Type": `multipart/form-data; boundary=${boundary}`,
          },
          body: `--${boundary}\r\nContent-Disposition`,
        });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });

    it("A maliciously malformed multipart request.", async () => {
      let serverError;

      const server = createServer(async (request, response) => {
        try {
          await rejects(processRequest(request, response), {
            name: "Error",
            message: "Malformed part header",
          });
        } catch (error) {
          serverError = error;
        } finally {
          response.end();
        }
      });

      const url = await listen(server);

      try {
        const boundary = "abcde";

        await fetch(url, {
          method: "POST",
          headers: {
            "Content-Type": `multipart/form-data; boundary=${boundary}`,
          },
          body: `--${boundary}\r\n Content-Disposition: form-data;`,
          //                      ^
          // Invalid space char at the header name start. See:
          // https://github.com/jaydenseric/graphql-upload/issues/311#issuecomment-1139513829
        });

        if (serverError) throw serverError;
      } finally {
        server.close();
      }
    });
  },
);