nstdlib-nightly/lib/internal/main/mksnapshot.mjs

Node.js standard library converted to runtime-agnostic ES modules.

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/internal/main/mksnapshot.js

import { BuiltinModule as __BuiltinModule__ } from "nstdlib/lib/internal/bootstrap/realm";
import {
  compileSerializeMain,
  anonymousMainPath,
} from "nstdlib/stub/binding/mksnapshot";
import { isExperimentalSeaWarningNeeded } from "nstdlib/stub/binding/sea";
import { emitExperimentalWarning } from "nstdlib/lib/internal/util";
import { emitWarningSync } from "nstdlib/lib/internal/process/warning";
import {
  initializeCallbacks,
  namespace as __namespace__,
} from "nstdlib/lib/internal/v8/startup_snapshot";
import { prepareMainThreadExecution } from "nstdlib/lib/internal/process/pre_execution";
import * as path from "nstdlib/lib/path";

const { normalizeRequirableId } = __BuiltinModule__;

const { addSerializeCallback, addDeserializeCallback, isBuildingSnapshot } =
  __namespace__;

const supportedModules = new Set(
  new (Array.prototype[Symbol.iterator]())([
    // '_http_agent',
    // '_http_client',
    // '_http_common',
    // '_http_incoming',
    // '_http_outgoing',
    // '_http_server',
    "_stream_duplex",
    "_stream_passthrough",
    "_stream_readable",
    "_stream_transform",
    "_stream_wrap",
    "_stream_writable",
    // '_tls_common',
    // '_tls_wrap',
    "assert",
    "assert/strict",
    // 'async_hooks',
    "buffer",
    // 'child_process',
    // 'cluster',
    "console",
    "constants",
    "crypto",
    // 'dgram',
    "diagnostics_channel",
    "dns",
    // 'dns/promises',
    // 'domain',
    "events",
    "fs",
    "fs/promises",
    // 'http',
    // 'http2',
    // 'https',
    // 'inspector',
    // 'module',
    "net",
    "os",
    "path",
    "path/posix",
    "path/win32",
    // 'perf_hooks',
    "process",
    "punycode",
    "querystring",
    // 'readline',
    // 'repl',
    "stream",
    "stream/promises",
    "string_decoder",
    "sys",
    "timers",
    "timers/promises",
    // 'tls',
    // 'trace_events',
    // 'tty',
    "url",
    "util",
    "util/types",
    "v8",
    // 'vm',
    // 'worker_threads',
    "zlib",
  ]),
);

const warnedModules = new Set();
function supportedInUserSnapshot(id) {
  return supportedModules.has(id);
}

function requireForUserSnapshot(id) {
  const normalizedId = normalizeRequirableId(id);
  if (!normalizedId) {
    // eslint-disable-next-line no-restricted-syntax
    const err = new Error(`Cannot find module '${id}'. `);
    err.code = "MODULE_NOT_FOUND";
    throw err;
  }
  if (isBuildingSnapshot() && !supportedInUserSnapshot(normalizedId)) {
    if (!warnedModules.has(normalizedId)) {
      // Emit the warning synchronously in case we don't get to process
      // the tick and print it before the unsupported built-in causes a
      // crash.
      emitWarningSync(
        `It's not yet fully verified whether built-in module "${id}" ` +
          "works in user snapshot builder scripts.\n" +
          "It may still work in some cases, but in other cases certain " +
          "run-time states may be out-of-sync after snapshot deserialization.\n" +
          "To request support for the module, use the Node.js issue tracker: " +
          "https://github.com/nodejs/node/issues",
      );
      warnedModules.add(normalizedId);
    }
  }

  return require(normalizedId);
}

function main() {
  prepareMainThreadExecution(false, false);
  initializeCallbacks();

  let stackTraceLimitDesc;
  addDeserializeCallback(() => {
    if (stackTraceLimitDesc !== undefined) {
      Object.defineProperty(Error, "stackTraceLimit", stackTraceLimitDesc);
    }
  });
  addSerializeCallback(() => {
    stackTraceLimitDesc = Object.getOwnPropertyDescriptor(
      Error,
      "stackTraceLimit",
    );

    if (stackTraceLimitDesc !== undefined) {
      // We want to use null-prototype objects to not rely on globally mutable
      // %Object.prototype%.
      Object.setPrototypeOf(stackTraceLimitDesc, null);
      process._rawDebug(
        "Deleting Error.stackTraceLimit from the snapshot. " +
          "It will be re-installed after deserialization",
      );
      delete Error.stackTraceLimit;
    }
  });

  // TODO(addaleax): Make this `embedderRunCjs` once require('module')
  // is supported in snapshots.
  function minimalRunCjs(source) {
    let filename;
    let dirname;
    if (process.argv[1] === anonymousMainPath) {
      filename = dirname = process.argv[1];
    } else {
      filename = path.resolve(process.argv[1]);
      dirname = path.dirname(filename);
    }

    const fn = compileSerializeMain(filename, source);
    return fn(requireForUserSnapshot, filename, dirname);
  }

  if (isExperimentalSeaWarningNeeded()) {
    emitExperimentalWarning("Single executable application");
  }

  return [process, requireForUserSnapshot, minimalRunCjs];
}

return main();