// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
"use strict";

((window) => {
  const core = window.Deno.core;
  const ops = core.ops;
  const { setExitHandler } = window.__bootstrap.os;
  const { Console } = window.__bootstrap.console;
  const { serializePermissions } = window.__bootstrap.permissions;
  const { assert } = window.__bootstrap.infra;
  const {
    ArrayFrom,
    ArrayPrototypeFilter,
    ArrayPrototypeJoin,
    ArrayPrototypeMap,
    ArrayPrototypePush,
    ArrayPrototypeShift,
    ArrayPrototypeSort,
    BigInt,
    DateNow,
    Error,
    FunctionPrototype,
    Map,
    MapPrototypeGet,
    MapPrototypeHas,
    MapPrototypeSet,
    MathCeil,
    ObjectKeys,
    ObjectPrototypeIsPrototypeOf,
    Promise,
    SafeArrayIterator,
    Set,
    SymbolToStringTag,
    TypeError,
  } = window.__bootstrap.primordials;

  const opSanitizerDelayResolveQueue = [];

  // Even if every resource is closed by the end of a test, there can be a delay
  // until the pending ops have all finished. This function returns a promise
  // that resolves when it's (probably) fine to run the op sanitizer.
  //
  // This is implemented by adding a macrotask callback that runs after the
  // timer macrotasks, so we can guarantee that a currently running interval
  // will have an associated op. An additional `setTimeout` of 0 is needed
  // before that, though, in order to give time for worker message ops to finish
  // (since timeouts of 0 don't queue tasks in the timer queue immediately).
  function opSanitizerDelay() {
    return new Promise((resolve) => {
      setTimeout(() => {
        ArrayPrototypePush(opSanitizerDelayResolveQueue, resolve);
      }, 0);
    });
  }

  function handleOpSanitizerDelayMacrotask() {
    ArrayPrototypeShift(opSanitizerDelayResolveQueue)?.();
    return opSanitizerDelayResolveQueue.length === 0;
  }

  // An async operation to $0 was started in this test, but never completed. This is often caused by not $1.
  // An async operation to $0 was started in this test, but never completed. Async operations should not complete in a test if they were not started in that test.
  // deno-fmt-ignore
  const OP_DETAILS = {
    "op_blob_read_part": ["read from a Blob or File", "awaiting the result of a Blob or File read"],
    "op_broadcast_recv": ["receive a message from a BroadcastChannel", "closing the BroadcastChannel"],
    "op_broadcast_send": ["send a message to a BroadcastChannel", "closing the BroadcastChannel"],
    "op_chmod_async": ["change the permissions of a file", "awaiting the result of a `Deno.chmod` call"],
    "op_chown_async": ["change the owner of a file", "awaiting the result of a `Deno.chown` call"],
    "op_copy_file_async": ["copy a file", "awaiting the result of a `Deno.copyFile` call"],
    "op_crypto_decrypt": ["decrypt data", "awaiting the result of a `crypto.subtle.decrypt` call"],
    "op_crypto_derive_bits": ["derive bits from a key", "awaiting the result of a `crypto.subtle.deriveBits` call"],
    "op_crypto_encrypt": ["encrypt data", "awaiting the result of a `crypto.subtle.encrypt` call"],
    "op_crypto_generate_key": ["generate a key", "awaiting the result of a `crypto.subtle.generateKey` call"],
    "op_crypto_sign_key": ["sign data", "awaiting the result of a `crypto.subtle.sign` call"],
    "op_crypto_subtle_digest": ["digest data", "awaiting the result of a `crypto.subtle.digest` call"],
    "op_crypto_verify_key": ["verify data", "awaiting the result of a `crypto.subtle.verify` call"],
    "op_net_recv_udp": ["receive a datagram message via UDP", "awaiting the result of `Deno.DatagramConn#receive` call, or not breaking out of a for await loop looping over a `Deno.DatagramConn`"],
    "op_net_recv_unixpacket": ["receive a datagram message via Unixpacket", "awaiting the result of `Deno.DatagramConn#receive` call, or not breaking out of a for await loop looping over a `Deno.DatagramConn`"],
    "op_net_send_udp": ["send a datagram message via UDP", "awaiting the result of `Deno.DatagramConn#send` call"],
    "op_net_send_unixpacket": ["send a datagram message via Unixpacket", "awaiting the result of `Deno.DatagramConn#send` call"],
    "op_dns_resolve": ["resolve a DNS name", "awaiting the result of a `Deno.resolveDns` call"],
    "op_fdatasync_async": ["flush pending data operations for a file to disk", "awaiting the result of a `Deno.fdatasync` call"],
    "op_fetch_send": ["send a HTTP request", "awaiting the result of a `fetch` call"],
    "op_ffi_call_nonblocking": ["do a non blocking ffi call", "awaiting the returned promise"] ,
    "op_ffi_call_ptr_nonblocking": ["do a non blocking ffi call",  "awaiting the returned promise"],
    "op_flock_async": ["lock a file", "awaiting the result of a `Deno.flock` call"],
    "op_fs_events_poll": ["get the next file system event", "breaking out of a for await loop looping over `Deno.FsEvents`"],
    "op_fstat_async": ["get file metadata", "awaiting the result of a `Deno.File#fstat` call"],
    "op_fsync_async": ["flush pending data operations for a file to disk", "awaiting the result of a `Deno.fsync` call"],
    "op_ftruncate_async": ["truncate a file", "awaiting the result of a `Deno.ftruncate` call"],
    "op_funlock_async": ["unlock a file", "awaiting the result of a `Deno.funlock` call"],
    "op_futime_async": ["change file timestamps", "awaiting the result of a `Deno.futime` call"],
    "op_http_accept": ["accept a HTTP request", "closing a `Deno.HttpConn`"],
    "op_http_shutdown": ["shutdown a HTTP connection", "awaiting `Deno.HttpEvent#respondWith`"],
    "op_http_upgrade_websocket": ["upgrade a HTTP connection to a WebSocket", "awaiting `Deno.HttpEvent#respondWith`"],
    "op_http_write_headers": ["write HTTP response headers", "awaiting `Deno.HttpEvent#respondWith`"],
    "op_http_write": ["write HTTP response body", "awaiting `Deno.HttpEvent#respondWith`"],
    "op_link_async": ["create a hard link", "awaiting the result of a `Deno.link` call"],
    "op_make_temp_dir_async": ["create a temporary directory", "awaiting the result of a `Deno.makeTempDir` call"],
    "op_make_temp_file_async": ["create a temporary file", "awaiting the result of a `Deno.makeTempFile` call"],
    "op_message_port_recv_message": ["receive a message from a MessagePort", "awaiting the result of not closing a `MessagePort`"],
    "op_mkdir_async": ["create a directory", "awaiting the result of a `Deno.mkdir` call"],
    "op_net_accept_tcp": ["accept a TCP stream", "closing a `Deno.Listener`"],
    "op_net_accept_unix": ["accept a Unix stream", "closing a `Deno.Listener`"],
    "op_net_connect_tcp": ["connect to a TCP server", "awaiting a `Deno.connect` call"],
    "op_net_connect_unix": ["connect to a Unix server", "awaiting a `Deno.connect` call"],
    "op_open_async": ["open a file", "awaiting the result of a `Deno.open` call"],
    "op_read_dir_async": ["read a directory", "collecting all items in the async iterable returned from a `Deno.readDir` call"],
    "op_read_link_async": ["read a symlink", "awaiting the result of a `Deno.readLink` call"],
    "op_realpath_async": ["resolve a path", "awaiting the result of a `Deno.realpath` call"],
    "op_remove_async": ["remove a file or directory", "awaiting the result of a `Deno.remove` call"],
    "op_rename_async": ["rename a file or directory", "awaiting the result of a `Deno.rename` call"],
    "op_run_status": ["get the status of a subprocess", "awaiting the result of a `Deno.Process#status` call"],
    "op_seek_async": ["seek in a file", "awaiting the result of a `Deno.File#seek` call"],
    "op_signal_poll": ["get the next signal", "un-registering a OS signal handler"],
    "op_sleep": ["sleep for a duration", "cancelling a `setTimeout` or `setInterval` call"],
    "op_stat_async": ["get file metadata", "awaiting the result of a `Deno.stat` call"],
    "op_symlink_async": ["create a symlink", "awaiting the result of a `Deno.symlink` call"],
    "op_net_accept_tls": ["accept a TLS stream", "closing a `Deno.TlsListener`"],
    "op_net_connect_tls": ["connect to a TLS server", "awaiting a `Deno.connectTls` call"],
    "op_tls_handshake": ["perform a TLS handshake", "awaiting a `Deno.TlsConn#handshake` call"],
    "op_tls_start": ["start a TLS connection", "awaiting a `Deno.startTls` call"],
    "op_truncate_async": ["truncate a file", "awaiting the result of a `Deno.truncate` call"],
    "op_utime_async": ["change file timestamps", "awaiting the result of a `Deno.utime` call"],
    "op_webgpu_buffer_get_map_async": ["map a WebGPU buffer", "awaiting the result of a `GPUBuffer#mapAsync` call"],
    "op_webgpu_request_adapter": ["request a WebGPU adapter", "awaiting the result of a `navigator.gpu.requestAdapter` call"],
    "op_webgpu_request_device": ["request a WebGPU device", "awaiting the result of a `GPUAdapter#requestDevice` call"],
    "op_worker_recv_message":  ["receive a message from a web worker", "terminating a `Worker`"],
    "op_ws_close": ["close a WebSocket", "awaiting until the `close` event is emitted on a `WebSocket`, or the `WebSocketStream#closed` promise resolves"],
    "op_ws_create": ["create a WebSocket", "awaiting until the `open` event is emitted on a `WebSocket`, or the result of a `WebSocketStream#connection` promise"],
    "op_ws_next_event": ["receive the next message on a WebSocket", "closing a `WebSocket` or `WebSocketStream`"],
    "op_ws_send": ["send a message on a WebSocket", "closing a `WebSocket` or `WebSocketStream`"],
  };

  // Wrap test function in additional assertion that makes sure
  // the test case does not leak async "ops" - ie. number of async
  // completed ops after the test is the same as number of dispatched
  // ops. Note that "unref" ops are ignored since in nature that are
  // optional.
  function assertOps(fn) {
    /** @param desc {TestDescription | TestStepDescription} */
    return async function asyncOpSanitizer(desc) {
      const pre = core.metrics();
      const preTraces = new Map(core.opCallTraces);
      try {
        await fn(desc);
      } finally {
        // Defer until next event loop turn - that way timeouts and intervals
        // cleared can actually be removed from resource table, otherwise
        // false positives may occur (https://github.com/denoland/deno/issues/4591)
        await opSanitizerDelay();
        await opSanitizerDelay();
      }

      if (shouldSkipSanitizers(desc)) return;

      const post = core.metrics();
      const postTraces = new Map(core.opCallTraces);

      // We're checking diff because one might spawn HTTP server in the background
      // that will be a pending async op before test starts.
      const dispatchedDiff = post.opsDispatchedAsync - pre.opsDispatchedAsync;
      const completedDiff = post.opsCompletedAsync - pre.opsCompletedAsync;

      if (dispatchedDiff === completedDiff) return;

      const details = [];
      for (const key in post.ops) {
        const preOp = pre.ops[key] ??
          { opsDispatchedAsync: 0, opsCompletedAsync: 0 };
        const postOp = post.ops[key];
        const dispatchedDiff = postOp.opsDispatchedAsync -
          preOp.opsDispatchedAsync;
        const completedDiff = postOp.opsCompletedAsync -
          preOp.opsCompletedAsync;

        if (dispatchedDiff > completedDiff) {
          const [name, hint] = OP_DETAILS[key] || [key, null];
          const count = dispatchedDiff - completedDiff;
          let message = `${count} async operation${
            count === 1 ? "" : "s"
          } to ${name} ${
            count === 1 ? "was" : "were"
          } started in this test, but never completed.`;
          if (hint) {
            message += ` This is often caused by not ${hint}.`;
          }
          const traces = [];
          for (const [id, { opName, stack }] of postTraces) {
            if (opName !== key) continue;
            if (MapPrototypeHas(preTraces, id)) continue;
            ArrayPrototypePush(traces, stack);
          }
          if (traces.length === 1) {
            message += " The operation was started here:\n";
            message += traces[0];
          } else if (traces.length > 1) {
            message += " The operations were started here:\n";
            message += ArrayPrototypeJoin(traces, "\n\n");
          }
          ArrayPrototypePush(details, message);
        } else if (dispatchedDiff < completedDiff) {
          const [name, hint] = OP_DETAILS[key] || [key, null];
          const count = completedDiff - dispatchedDiff;
          ArrayPrototypePush(
            details,
            `${count} async operation${count === 1 ? "" : "s"} to ${name} ${
              count === 1 ? "was" : "were"
            } started before this test, but ${
              count === 1 ? "was" : "were"
            } completed during the test. Async operations should not complete in a test if they were not started in that test.
            ${hint ? `This is often caused by not ${hint}.` : ""}`,
          );
        }
      }

      let msg = `Test case is leaking async ops.

 - ${ArrayPrototypeJoin(details, "\n - ")}`;

      if (!core.isOpCallTracingEnabled()) {
        msg +=
          `\n\nTo get more details where ops were leaked, run again with --trace-ops flag.`;
      } else {
        msg += "\n";
      }

      throw assert(false, msg);
    };
  }

  function prettyResourceNames(name) {
    switch (name) {
      case "fsFile":
        return ["A file", "opened", "closed"];
      case "fetchRequest":
        return ["A fetch request", "started", "finished"];
      case "fetchRequestBody":
        return ["A fetch request body", "created", "closed"];
      case "fetchResponseBody":
        return ["A fetch response body", "created", "consumed"];
      case "httpClient":
        return ["An HTTP client", "created", "closed"];
      case "dynamicLibrary":
        return ["A dynamic library", "loaded", "unloaded"];
      case "httpConn":
        return ["An inbound HTTP connection", "accepted", "closed"];
      case "httpStream":
        return ["An inbound HTTP request", "accepted", "closed"];
      case "tcpStream":
        return ["A TCP connection", "opened/accepted", "closed"];
      case "unixStream":
        return ["A Unix connection", "opened/accepted", "closed"];
      case "tlsStream":
        return ["A TLS connection", "opened/accepted", "closed"];
      case "tlsListener":
        return ["A TLS listener", "opened", "closed"];
      case "unixListener":
        return ["A Unix listener", "opened", "closed"];
      case "unixDatagram":
        return ["A Unix datagram", "opened", "closed"];
      case "tcpListener":
        return ["A TCP listener", "opened", "closed"];
      case "udpSocket":
        return ["A UDP socket", "opened", "closed"];
      case "timer":
        return ["A timer", "started", "fired/cleared"];
      case "textDecoder":
        return ["A text decoder", "created", "finished"];
      case "messagePort":
        return ["A message port", "created", "closed"];
      case "webSocketStream":
        return ["A WebSocket", "opened", "closed"];
      case "fsEvents":
        return ["A file system watcher", "created", "closed"];
      case "childStdin":
        return ["A child process stdin", "opened", "closed"];
      case "childStdout":
        return ["A child process stdout", "opened", "closed"];
      case "childStderr":
        return ["A child process stderr", "opened", "closed"];
      case "child":
        return ["A child process", "started", "closed"];
      case "signal":
        return ["A signal listener", "created", "fired/cleared"];
      case "stdin":
        return ["The stdin pipe", "opened", "closed"];
      case "stdout":
        return ["The stdout pipe", "opened", "closed"];
      case "stderr":
        return ["The stderr pipe", "opened", "closed"];
      case "compression":
        return ["A CompressionStream", "created", "closed"];
      default:
        return [`A "${name}" resource`, "created", "cleaned up"];
    }
  }

  function resourceCloseHint(name) {
    switch (name) {
      case "fsFile":
        return "Close the file handle by calling `file.close()`.";
      case "fetchRequest":
        return "Await the promise returned from `fetch()` or abort the fetch with an abort signal.";
      case "fetchRequestBody":
        return "Terminate the request body `ReadableStream` by closing or erroring it.";
      case "fetchResponseBody":
        return "Consume or close the response body `ReadableStream`, e.g `await resp.text()` or `await resp.body.cancel()`.";
      case "httpClient":
        return "Close the HTTP client by calling `httpClient.close()`.";
      case "dynamicLibrary":
        return "Unload the dynamic library by calling `dynamicLibrary.close()`.";
      case "httpConn":
        return "Close the inbound HTTP connection by calling `httpConn.close()`.";
      case "httpStream":
        return "Close the inbound HTTP request by responding with `e.respondWith().` or closing the HTTP connection.";
      case "tcpStream":
        return "Close the TCP connection by calling `tcpConn.close()`.";
      case "unixStream":
        return "Close the Unix socket connection by calling `unixConn.close()`.";
      case "tlsStream":
        return "Close the TLS connection by calling `tlsConn.close()`.";
      case "tlsListener":
        return "Close the TLS listener by calling `tlsListener.close()`.";
      case "unixListener":
        return "Close the Unix socket listener by calling `unixListener.close()`.";
      case "unixDatagram":
        return "Close the Unix datagram socket by calling `unixDatagram.close()`.";
      case "tcpListener":
        return "Close the TCP listener by calling `tcpListener.close()`.";
      case "udpSocket":
        return "Close the UDP socket by calling `udpSocket.close()`.";
      case "timer":
        return "Clear the timer by calling `clearInterval` or `clearTimeout`.";
      case "textDecoder":
        return "Close the text decoder by calling `textDecoder.decode('')` or `await textDecoderStream.readable.cancel()`.";
      case "messagePort":
        return "Close the message port by calling `messagePort.close()`.";
      case "webSocketStream":
        return "Close the WebSocket by calling `webSocket.close()`.";
      case "fsEvents":
        return "Close the file system watcher by calling `watcher.close()`.";
      case "childStdin":
        return "Close the child process stdin by calling `proc.stdin.close()`.";
      case "childStdout":
        return "Close the child process stdout by calling `proc.stdout.close()`.";
      case "childStderr":
        return "Close the child process stderr by calling `proc.stderr.close()`.";
      case "child":
        return "Close the child process by calling `proc.kill()` or `proc.close()`.";
      case "signal":
        return "Clear the signal listener by calling `Deno.removeSignalListener`.";
      case "stdin":
        return "Close the stdin pipe by calling `Deno.stdin.close()`.";
      case "stdout":
        return "Close the stdout pipe by calling `Deno.stdout.close()`.";
      case "stderr":
        return "Close the stderr pipe by calling `Deno.stderr.close()`.";
      case "compression":
        return "Close the compression stream by calling `await stream.writable.close()`.";
      default:
        return "Close the resource before the end of the test.";
    }
  }

  // Wrap test function in additional assertion that makes sure
  // the test case does not "leak" resources - ie. resource table after
  // the test has exactly the same contents as before the test.
  function assertResources(fn) {
    /** @param desc {TestDescription | TestStepDescription} */
    return async function resourceSanitizer(desc) {
      const pre = core.resources();
      await fn(desc);

      if (shouldSkipSanitizers(desc)) {
        return;
      }

      const post = core.resources();

      const allResources = new Set([
        ...new SafeArrayIterator(ObjectKeys(pre)),
        ...new SafeArrayIterator(ObjectKeys(post)),
      ]);

      const details = [];
      for (const resource of allResources) {
        const preResource = pre[resource];
        const postResource = post[resource];
        if (preResource === postResource) continue;

        if (preResource === undefined) {
          const [name, action1, action2] = prettyResourceNames(postResource);
          const hint = resourceCloseHint(postResource);
          const detail =
            `${name} (rid ${resource}) was ${action1} during the test, but not ${action2} during the test. ${hint}`;
          ArrayPrototypePush(details, detail);
        } else {
          const [name, action1, action2] = prettyResourceNames(preResource);
          const detail =
            `${name} (rid ${resource}) was ${action1} before the test started, but was ${action2} during the test. Do not close resources in a test that were not created during that test.`;
          ArrayPrototypePush(details, detail);
        }
      }

      const message = `Test case is leaking ${details.length} resource${
        details.length === 1 ? "" : "s"
      }:

 - ${details.join("\n - ")}
`;
      assert(details.length === 0, message);
    };
  }

  // Wrap test function in additional assertion that makes sure
  // that the test case does not accidentally exit prematurely.
  function assertExit(fn, isTest) {
    return async function exitSanitizer(...params) {
      setExitHandler((exitCode) => {
        assert(
          false,
          `${
            isTest ? "Test case" : "Bench"
          } attempted to exit with exit code: ${exitCode}`,
        );
      });

      try {
        await fn(...new SafeArrayIterator(params));
      } catch (err) {
        throw err;
      } finally {
        setExitHandler(null);
      }
    };
  }

  function assertTestStepScopes(fn) {
    /** @param desc {TestDescription | TestStepDescription} */
    return async function testStepSanitizer(desc) {
      preValidation();
      // only report waiting after pre-validation
      if (canStreamReporting(desc) && "parent" in desc) {
        stepReportWait(desc);
      }
      await fn(MapPrototypeGet(testStates, desc.id).context);
      testStepPostValidation(desc);

      function preValidation() {
        const runningStepDescs = getRunningStepDescs();
        const runningStepDescsWithSanitizers = ArrayPrototypeFilter(
          runningStepDescs,
          (d) => usesSanitizer(d),
        );

        if (runningStepDescsWithSanitizers.length > 0) {
          throw new Error(
            "Cannot start test step while another test step with sanitizers is running.\n" +
              runningStepDescsWithSanitizers
                .map((d) => ` * ${getFullName(d)}`)
                .join("\n"),
          );
        }

        if (usesSanitizer(desc) && runningStepDescs.length > 0) {
          throw new Error(
            "Cannot start test step with sanitizers while another test step is running.\n" +
              runningStepDescs.map((d) => ` * ${getFullName(d)}`).join("\n"),
          );
        }

        function getRunningStepDescs() {
          const results = [];
          let childDesc = desc;
          while (childDesc.parent != null) {
            const state = MapPrototypeGet(testStates, childDesc.parent.id);
            for (const siblingDesc of state.children) {
              if (siblingDesc.id == childDesc.id) {
                continue;
              }
              const siblingState = MapPrototypeGet(testStates, siblingDesc.id);
              if (!siblingState.finalized) {
                ArrayPrototypePush(results, siblingDesc);
              }
            }
            childDesc = childDesc.parent;
          }
          return results;
        }
      }
    };
  }

  function testStepPostValidation(desc) {
    // check for any running steps
    for (const childDesc of MapPrototypeGet(testStates, desc.id).children) {
      if (MapPrototypeGet(testStates, childDesc.id).status == "pending") {
        throw new Error(
          "There were still test steps running after the current scope finished execution. Ensure all steps are awaited (ex. `await t.step(...)`).",
        );
      }
    }

    // check if an ancestor already completed
    let currentDesc = desc.parent;
    while (currentDesc != null) {
      if (MapPrototypeGet(testStates, currentDesc.id).finalized) {
        throw new Error(
          "Parent scope completed before test step finished execution. Ensure all steps are awaited (ex. `await t.step(...)`).",
        );
      }
      currentDesc = currentDesc.parent;
    }
  }

  function pledgePermissions(permissions) {
    return ops.op_pledge_test_permissions(
      serializePermissions(permissions),
    );
  }

  function restorePermissions(token) {
    ops.op_restore_test_permissions(token);
  }

  function withPermissions(fn, permissions) {
    return async function applyPermissions(...params) {
      const token = pledgePermissions(permissions);

      try {
        await fn(...new SafeArrayIterator(params));
      } finally {
        restorePermissions(token);
      }
    };
  }

  /**
   * @typedef {{
   *   id: number,
   *   name: string,
   *   fn: TestFunction
   *   origin: string,
   *   location: TestLocation,
   *   filteredOut: boolean,
   *   ignore: boolean,
   *   only: boolean.
   *   sanitizeOps: boolean,
   *   sanitizeResources: boolean,
   *   sanitizeExit: boolean,
   *   permissions: PermissionOptions,
   * }} TestDescription
   *
   * @typedef {{
   *   id: number,
   *   name: string,
   *   fn: TestFunction
   *   origin: string,
   *   location: TestLocation,
   *   ignore: boolean,
   *   level: number,
   *   parent: TestDescription | TestStepDescription,
   *   rootId: number,
   *   rootName: String,
   *   sanitizeOps: boolean,
   *   sanitizeResources: boolean,
   *   sanitizeExit: boolean,
   * }} TestStepDescription
   *
   * @typedef {{
   *   context: TestContext,
   *   children: TestStepDescription[],
   *   finalized: boolean,
   * }} TestState
   *
   * @typedef {{
   *   context: TestContext,
   *   children: TestStepDescription[],
   *   finalized: boolean,
   *   status: "pending" | "ok" | ""failed" | ignored",
   *   error: unknown,
   *   elapsed: number | null,
   *   reportedWait: boolean,
   *   reportedResult: boolean,
   * }} TestStepState
   *
   * @typedef {{
   *   id: number,
   *   name: string,
   *   fn: BenchFunction
   *   origin: string,
   *   filteredOut: boolean,
   *   ignore: boolean,
   *   only: boolean.
   *   sanitizeExit: boolean,
   *   permissions: PermissionOptions,
   * }} BenchDescription
   */

  /** @type {TestDescription[]} */
  const testDescs = [];
  /** @type {Map<number, TestState | TestStepState>} */
  const testStates = new Map();
  /** @type {BenchDescription[]} */
  const benchDescs = [];
  let isTestSubcommand = false;
  let isBenchSubcommand = false;

  // Main test function provided by Deno.
  function test(
    nameOrFnOrOptions,
    optionsOrFn,
    maybeFn,
  ) {
    if (!isTestSubcommand) {
      return;
    }

    let testDesc;
    const defaults = {
      ignore: false,
      only: false,
      sanitizeOps: true,
      sanitizeResources: true,
      sanitizeExit: true,
      permissions: null,
    };

    if (typeof nameOrFnOrOptions === "string") {
      if (!nameOrFnOrOptions) {
        throw new TypeError("The test name can't be empty");
      }
      if (typeof optionsOrFn === "function") {
        testDesc = { fn: optionsOrFn, name: nameOrFnOrOptions, ...defaults };
      } else {
        if (!maybeFn || typeof maybeFn !== "function") {
          throw new TypeError("Missing test function");
        }
        if (optionsOrFn.fn != undefined) {
          throw new TypeError(
            "Unexpected 'fn' field in options, test function is already provided as the third argument.",
          );
        }
        if (optionsOrFn.name != undefined) {
          throw new TypeError(
            "Unexpected 'name' field in options, test name is already provided as the first argument.",
          );
        }
        testDesc = {
          ...defaults,
          ...optionsOrFn,
          fn: maybeFn,
          name: nameOrFnOrOptions,
        };
      }
    } else if (typeof nameOrFnOrOptions === "function") {
      if (!nameOrFnOrOptions.name) {
        throw new TypeError("The test function must have a name");
      }
      if (optionsOrFn != undefined) {
        throw new TypeError("Unexpected second argument to Deno.test()");
      }
      if (maybeFn != undefined) {
        throw new TypeError("Unexpected third argument to Deno.test()");
      }
      testDesc = {
        ...defaults,
        fn: nameOrFnOrOptions,
        name: nameOrFnOrOptions.name,
      };
    } else {
      let fn;
      let name;
      if (typeof optionsOrFn === "function") {
        fn = optionsOrFn;
        if (nameOrFnOrOptions.fn != undefined) {
          throw new TypeError(
            "Unexpected 'fn' field in options, test function is already provided as the second argument.",
          );
        }
        name = nameOrFnOrOptions.name ?? fn.name;
      } else {
        if (
          !nameOrFnOrOptions.fn || typeof nameOrFnOrOptions.fn !== "function"
        ) {
          throw new TypeError(
            "Expected 'fn' field in the first argument to be a test function.",
          );
        }
        fn = nameOrFnOrOptions.fn;
        name = nameOrFnOrOptions.name ?? fn.name;
      }
      if (!name) {
        throw new TypeError("The test name can't be empty");
      }
      testDesc = { ...defaults, ...nameOrFnOrOptions, fn, name };
    }

    // Delete this prop in case the user passed it. It's used to detect steps.
    delete testDesc.parent;
    testDesc.fn = wrapTestFnWithSanitizers(testDesc.fn, testDesc);
    if (testDesc.permissions) {
      testDesc.fn = withPermissions(
        testDesc.fn,
        testDesc.permissions,
      );
    }
    testDesc.origin = getTestOrigin();
    const jsError = Deno.core.destructureError(new Error());
    testDesc.location = {
      fileName: jsError.frames[1].fileName,
      lineNumber: jsError.frames[1].lineNumber,
      columnNumber: jsError.frames[1].columnNumber,
    };

    const { id, filteredOut } = ops.op_register_test(testDesc);
    testDesc.id = id;
    testDesc.filteredOut = filteredOut;

    ArrayPrototypePush(testDescs, testDesc);
    MapPrototypeSet(testStates, testDesc.id, {
      context: createTestContext(testDesc),
      children: [],
      finalized: false,
    });
  }

  // Main bench function provided by Deno.
  function bench(
    nameOrFnOrOptions,
    optionsOrFn,
    maybeFn,
  ) {
    if (!isBenchSubcommand) {
      return;
    }

    ops.op_bench_check_unstable();
    let benchDesc;
    const defaults = {
      ignore: false,
      baseline: false,
      only: false,
      sanitizeExit: true,
      permissions: null,
    };

    if (typeof nameOrFnOrOptions === "string") {
      if (!nameOrFnOrOptions) {
        throw new TypeError("The bench name can't be empty");
      }
      if (typeof optionsOrFn === "function") {
        benchDesc = { fn: optionsOrFn, name: nameOrFnOrOptions, ...defaults };
      } else {
        if (!maybeFn || typeof maybeFn !== "function") {
          throw new TypeError("Missing bench function");
        }
        if (optionsOrFn.fn != undefined) {
          throw new TypeError(
            "Unexpected 'fn' field in options, bench function is already provided as the third argument.",
          );
        }
        if (optionsOrFn.name != undefined) {
          throw new TypeError(
            "Unexpected 'name' field in options, bench name is already provided as the first argument.",
          );
        }
        benchDesc = {
          ...defaults,
          ...optionsOrFn,
          fn: maybeFn,
          name: nameOrFnOrOptions,
        };
      }
    } else if (typeof nameOrFnOrOptions === "function") {
      if (!nameOrFnOrOptions.name) {
        throw new TypeError("The bench function must have a name");
      }
      if (optionsOrFn != undefined) {
        throw new TypeError("Unexpected second argument to Deno.bench()");
      }
      if (maybeFn != undefined) {
        throw new TypeError("Unexpected third argument to Deno.bench()");
      }
      benchDesc = {
        ...defaults,
        fn: nameOrFnOrOptions,
        name: nameOrFnOrOptions.name,
      };
    } else {
      let fn;
      let name;
      if (typeof optionsOrFn === "function") {
        fn = optionsOrFn;
        if (nameOrFnOrOptions.fn != undefined) {
          throw new TypeError(
            "Unexpected 'fn' field in options, bench function is already provided as the second argument.",
          );
        }
        name = nameOrFnOrOptions.name ?? fn.name;
      } else {
        if (
          !nameOrFnOrOptions.fn || typeof nameOrFnOrOptions.fn !== "function"
        ) {
          throw new TypeError(
            "Expected 'fn' field in the first argument to be a bench function.",
          );
        }
        fn = nameOrFnOrOptions.fn;
        name = nameOrFnOrOptions.name ?? fn.name;
      }
      if (!name) {
        throw new TypeError("The bench name can't be empty");
      }
      benchDesc = { ...defaults, ...nameOrFnOrOptions, fn, name };
    }

    benchDesc.origin = getBenchOrigin();
    const AsyncFunction = (async () => {}).constructor;
    benchDesc.async = AsyncFunction === benchDesc.fn.constructor;

    const { id, filteredOut } = ops.op_register_bench(benchDesc);
    benchDesc.id = id;
    benchDesc.filteredOut = filteredOut;

    ArrayPrototypePush(benchDescs, benchDesc);
  }

  async function runTest(desc) {
    if (desc.ignore) {
      return "ignored";
    }

    try {
      await desc.fn(desc);
      const failCount = failedChildStepsCount(desc);
      return failCount === 0 ? "ok" : {
        "failed": core.destructureError(
          new Error(
            `${failCount} test step${failCount === 1 ? "" : "s"} failed.`,
          ),
        ),
      };
    } catch (error) {
      return {
        "failed": core.destructureError(error),
      };
    } finally {
      const state = MapPrototypeGet(testStates, desc.id);
      state.finalized = true;
      // ensure the children report their result
      for (const childDesc of state.children) {
        stepReportResult(childDesc);
      }
    }
  }

  function compareMeasurements(a, b) {
    if (a > b) return 1;
    if (a < b) return -1;

    return 0;
  }

  function benchStats(n, highPrecision, avg, min, max, all) {
    return {
      n,
      min,
      max,
      p75: all[MathCeil(n * (75 / 100)) - 1],
      p99: all[MathCeil(n * (99 / 100)) - 1],
      p995: all[MathCeil(n * (99.5 / 100)) - 1],
      p999: all[MathCeil(n * (99.9 / 100)) - 1],
      avg: !highPrecision ? (avg / n) : MathCeil(avg / n),
    };
  }

  async function benchMeasure(timeBudget, desc) {
    const fn = desc.fn;
    let n = 0;
    let avg = 0;
    let wavg = 0;
    const all = [];
    let min = Infinity;
    let max = -Infinity;
    const lowPrecisionThresholdInNs = 1e4;

    // warmup step
    let c = 0;
    let iterations = 20;
    let budget = 10 * 1e6;

    if (!desc.async) {
      while (budget > 0 || iterations-- > 0) {
        const t1 = benchNow();

        fn();
        const iterationTime = benchNow() - t1;

        c++;
        wavg += iterationTime;
        budget -= iterationTime;
      }
    } else {
      while (budget > 0 || iterations-- > 0) {
        const t1 = benchNow();

        await fn();
        const iterationTime = benchNow() - t1;

        c++;
        wavg += iterationTime;
        budget -= iterationTime;
      }
    }

    wavg /= c;

    // measure step
    if (wavg > lowPrecisionThresholdInNs) {
      let iterations = 10;
      let budget = timeBudget * 1e6;

      if (!desc.async) {
        while (budget > 0 || iterations-- > 0) {
          const t1 = benchNow();

          fn();
          const iterationTime = benchNow() - t1;

          n++;
          avg += iterationTime;
          budget -= iterationTime;
          ArrayPrototypePush(all, iterationTime);
          if (iterationTime < min) min = iterationTime;
          if (iterationTime > max) max = iterationTime;
        }
      } else {
        while (budget > 0 || iterations-- > 0) {
          const t1 = benchNow();

          await fn();
          const iterationTime = benchNow() - t1;

          n++;
          avg += iterationTime;
          budget -= iterationTime;
          ArrayPrototypePush(all, iterationTime);
          if (iterationTime < min) min = iterationTime;
          if (iterationTime > max) max = iterationTime;
        }
      }
    } else {
      let iterations = 10;
      let budget = timeBudget * 1e6;

      if (!desc.async) {
        while (budget > 0 || iterations-- > 0) {
          const t1 = benchNow();
          for (let c = 0; c < lowPrecisionThresholdInNs; c++) fn();
          const iterationTime = (benchNow() - t1) / lowPrecisionThresholdInNs;

          n++;
          avg += iterationTime;
          ArrayPrototypePush(all, iterationTime);
          if (iterationTime < min) min = iterationTime;
          if (iterationTime > max) max = iterationTime;
          budget -= iterationTime * lowPrecisionThresholdInNs;
        }
      } else {
        while (budget > 0 || iterations-- > 0) {
          const t1 = benchNow();
          for (let c = 0; c < lowPrecisionThresholdInNs; c++) await fn();
          const iterationTime = (benchNow() - t1) / lowPrecisionThresholdInNs;

          n++;
          avg += iterationTime;
          ArrayPrototypePush(all, iterationTime);
          if (iterationTime < min) min = iterationTime;
          if (iterationTime > max) max = iterationTime;
          budget -= iterationTime * lowPrecisionThresholdInNs;
        }
      }
    }

    all.sort(compareMeasurements);
    return benchStats(n, wavg > lowPrecisionThresholdInNs, avg, min, max, all);
  }

  async function runBench(desc) {
    let token = null;

    try {
      if (desc.permissions) {
        token = pledgePermissions(desc.permissions);
      }

      if (desc.sanitizeExit) {
        setExitHandler((exitCode) => {
          assert(
            false,
            `Bench attempted to exit with exit code: ${exitCode}`,
          );
        });
      }

      const benchTimeInMs = 500;
      const stats = await benchMeasure(benchTimeInMs, desc);

      return { ok: stats };
    } catch (error) {
      return { failed: core.destructureError(error) };
    } finally {
      if (bench.sanitizeExit) setExitHandler(null);
      if (token !== null) restorePermissions(token);
    }
  }

  let origin = null;

  function getTestOrigin() {
    if (origin == null) {
      origin = ops.op_get_test_origin();
    }
    return origin;
  }

  function getBenchOrigin() {
    if (origin == null) {
      origin = ops.op_get_bench_origin();
    }
    return origin;
  }

  function benchNow() {
    return ops.op_bench_now();
  }

  function enableTest() {
    isTestSubcommand = true;
  }

  function enableBench() {
    isBenchSubcommand = true;
  }

  async function runTests({
    shuffle = null,
  } = {}) {
    core.setMacrotaskCallback(handleOpSanitizerDelayMacrotask);

    const origin = getTestOrigin();
    const only = ArrayPrototypeFilter(testDescs, (test) => test.only);
    const filtered = ArrayPrototypeFilter(
      only.length > 0 ? only : testDescs,
      (desc) => !desc.filteredOut,
    );

    ops.op_dispatch_test_event({
      plan: {
        origin,
        total: filtered.length,
        filteredOut: testDescs.length - filtered.length,
        usedOnly: only.length > 0,
      },
    });

    if (shuffle !== null) {
      // http://en.wikipedia.org/wiki/Linear_congruential_generator
      // Use BigInt for everything because the random seed is u64.
      const nextInt = (function (state) {
        const m = 0x80000000n;
        const a = 1103515245n;
        const c = 12345n;

        return function (max) {
          return state = ((a * state + c) % m) % BigInt(max);
        };
      }(BigInt(shuffle)));

      for (let i = filtered.length - 1; i > 0; i--) {
        const j = nextInt(i);
        [filtered[i], filtered[j]] = [filtered[j], filtered[i]];
      }
    }

    for (const desc of filtered) {
      ops.op_dispatch_test_event({ wait: desc.id });
      const earlier = DateNow();
      const result = await runTest(desc);
      const elapsed = DateNow() - earlier;
      ops.op_dispatch_test_event({
        result: [desc.id, result, elapsed],
      });
    }
  }

  async function runBenchmarks() {
    core.setMacrotaskCallback(handleOpSanitizerDelayMacrotask);

    const origin = getBenchOrigin();
    const originalConsole = globalThis.console;

    globalThis.console = new Console((s) => {
      ops.op_dispatch_bench_event({ output: s });
    });

    const only = ArrayPrototypeFilter(benchDescs, (bench) => bench.only);
    const filtered = ArrayPrototypeFilter(
      only.length > 0 ? only : benchDescs,
      (desc) => !desc.filteredOut && !desc.ignore,
    );

    let groups = new Set();
    // make sure ungrouped benchmarks are placed above grouped
    groups.add(undefined);

    for (const desc of filtered) {
      desc.group ||= undefined;
      groups.add(desc.group);
    }

    groups = ArrayFrom(groups);
    ArrayPrototypeSort(
      filtered,
      (a, b) => groups.indexOf(a.group) - groups.indexOf(b.group),
    );

    ops.op_dispatch_bench_event({
      plan: {
        origin,
        total: filtered.length,
        usedOnly: only.length > 0,
        names: ArrayPrototypeMap(filtered, (desc) => desc.name),
      },
    });

    for (const desc of filtered) {
      desc.baseline = !!desc.baseline;
      ops.op_dispatch_bench_event({ wait: desc.id });
      ops.op_dispatch_bench_event({
        result: [desc.id, await runBench(desc)],
      });
    }

    globalThis.console = originalConsole;
  }

  function getFullName(desc) {
    if ("parent" in desc) {
      return `${desc.parent.name} > ${desc.name}`;
    }
    return desc.name;
  }

  function usesSanitizer(desc) {
    return desc.sanitizeResources || desc.sanitizeOps || desc.sanitizeExit;
  }

  function canStreamReporting(desc) {
    let currentDesc = desc;
    while (currentDesc != null) {
      if (!usesSanitizer(currentDesc)) {
        return false;
      }
      currentDesc = currentDesc.parent;
    }
    for (const childDesc of MapPrototypeGet(testStates, desc.id).children) {
      const state = MapPrototypeGet(testStates, childDesc.id);
      if (!usesSanitizer(childDesc) && !state.finalized) {
        return false;
      }
    }
    return true;
  }

  function stepReportWait(desc) {
    const state = MapPrototypeGet(testStates, desc.id);
    if (state.reportedWait) {
      return;
    }
    ops.op_dispatch_test_event({ stepWait: desc.id });
    state.reportedWait = true;
  }

  function stepReportResult(desc) {
    const state = MapPrototypeGet(testStates, desc.id);
    if (state.reportedResult) {
      return;
    }
    stepReportWait(desc);
    for (const childDesc of state.children) {
      stepReportResult(childDesc);
    }
    let result;
    if (state.status == "pending" || state.status == "failed") {
      result = {
        [state.status]: state.error && core.destructureError(state.error),
      };
    } else {
      result = state.status;
    }
    ops.op_dispatch_test_event({
      stepResult: [desc.id, result, state.elapsed],
    });
    state.reportedResult = true;
  }

  function failedChildStepsCount(desc) {
    return ArrayPrototypeFilter(
      MapPrototypeGet(testStates, desc.id).children,
      (d) => MapPrototypeGet(testStates, d.id).status === "failed",
    ).length;
  }

  /** If a test validation error already occurred then don't bother checking
   * the sanitizers as that will create extra noise.
   */
  function shouldSkipSanitizers(desc) {
    try {
      testStepPostValidation(desc);
      return false;
    } catch {
      return true;
    }
  }

  /** @param desc {TestDescription | TestStepDescription} */
  function createTestContext(desc) {
    let parent;
    let level;
    let rootId;
    let rootName;
    if ("parent" in desc) {
      parent = MapPrototypeGet(testStates, desc.parent.id).context;
      level = desc.level;
      rootId = desc.rootId;
      rootName = desc.rootName;
    } else {
      parent = undefined;
      level = 0;
      rootId = desc.id;
      rootName = desc.name;
    }
    return {
      [SymbolToStringTag]: "TestContext",
      /**
       * The current test name.
       */
      name: desc.name,
      /**
       * Parent test context.
       */
      parent,
      /**
       * File Uri of the test code.
       */
      origin: desc.origin,
      /**
       * @param nameOrTestDefinition {string | TestStepDefinition}
       * @param fn {(t: TestContext) => void | Promise<void>}
       */
      async step(nameOrTestDefinition, fn) {
        if (MapPrototypeGet(testStates, desc.id).finalized) {
          throw new Error(
            "Cannot run test step after parent scope has finished execution. " +
              "Ensure any `.step(...)` calls are executed before their parent scope completes execution.",
          );
        }

        let stepDesc;
        if (typeof nameOrTestDefinition === "string") {
          if (!(ObjectPrototypeIsPrototypeOf(FunctionPrototype, fn))) {
            throw new TypeError("Expected function for second argument.");
          }
          stepDesc = {
            name: nameOrTestDefinition,
            fn,
          };
        } else if (typeof nameOrTestDefinition === "object") {
          stepDesc = nameOrTestDefinition;
        } else {
          throw new TypeError(
            "Expected a test definition or name and function.",
          );
        }
        stepDesc.ignore ??= false;
        stepDesc.sanitizeOps ??= desc.sanitizeOps;
        stepDesc.sanitizeResources ??= desc.sanitizeResources;
        stepDesc.sanitizeExit ??= desc.sanitizeExit;
        stepDesc.origin = getTestOrigin();
        const jsError = Deno.core.destructureError(new Error());
        stepDesc.location = {
          fileName: jsError.frames[1].fileName,
          lineNumber: jsError.frames[1].lineNumber,
          columnNumber: jsError.frames[1].columnNumber,
        };
        stepDesc.level = level + 1;
        stepDesc.parent = desc;
        stepDesc.rootId = rootId;
        stepDesc.rootName = rootName;
        const { id } = ops.op_register_test_step(stepDesc);
        stepDesc.id = id;
        const state = {
          context: createTestContext(stepDesc),
          children: [],
          finalized: false,
          status: "pending",
          error: null,
          elapsed: null,
          reportedWait: false,
          reportedResult: false,
        };
        MapPrototypeSet(testStates, stepDesc.id, state);
        ArrayPrototypePush(
          MapPrototypeGet(testStates, stepDesc.parent.id).children,
          stepDesc,
        );

        try {
          if (stepDesc.ignore) {
            state.status = "ignored";
            state.finalized = true;
            if (canStreamReporting(stepDesc)) {
              stepReportResult(stepDesc);
            }
            return false;
          }

          const testFn = wrapTestFnWithSanitizers(stepDesc.fn, stepDesc);
          const start = DateNow();

          try {
            await testFn(stepDesc);

            if (failedChildStepsCount(stepDesc) > 0) {
              state.status = "failed";
            } else {
              state.status = "ok";
            }
          } catch (error) {
            state.error = error;
            state.status = "failed";
          }

          state.elapsed = DateNow() - start;

          if (MapPrototypeGet(testStates, stepDesc.parent.id).finalized) {
            // always point this test out as one that was still running
            // if the parent step finalized
            state.status = "pending";
          }

          state.finalized = true;

          if (state.reportedWait && canStreamReporting(stepDesc)) {
            stepReportResult(stepDesc);
          }

          return state.status === "ok";
        } finally {
          if (canStreamReporting(stepDesc.parent)) {
            const parentState = MapPrototypeGet(testStates, stepDesc.parent.id);
            // flush any buffered steps
            for (const childDesc of parentState.children) {
              stepReportResult(childDesc);
            }
          }
        }
      },
    };
  }

  /**
   * @template T {Function}
   * @param testFn {T}
   * @param opts {{
   *   sanitizeOps: boolean,
   *   sanitizeResources: boolean,
   *   sanitizeExit: boolean,
   * }}
   * @returns {T}
   */
  function wrapTestFnWithSanitizers(testFn, opts) {
    testFn = assertTestStepScopes(testFn);

    if (opts.sanitizeOps) {
      testFn = assertOps(testFn);
    }
    if (opts.sanitizeResources) {
      testFn = assertResources(testFn);
    }
    if (opts.sanitizeExit) {
      testFn = assertExit(testFn, true);
    }
    return testFn;
  }

  window.__bootstrap.testing = {
    bench,
    enableBench,
    enableTest,
    runBenchmarks,
    runTests,
    test,
  };
})(this);