prepack/lib/intrinsics/ecma262/Error.js

Execute a JS bundle, serialize global state and side effects to a snapshot that can be quickly restored.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = _default;
exports.describeLocation = describeLocation;
exports.build = build;

var _index = require("../../values/index.js");

var _index2 = require("../../methods/index.js");

var _singletons = require("../../singletons.js");

var _invariant = _interopRequireDefault(require("../../invariant.js"));

var _descriptors = require("../../descriptors.js");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * Copyright (c) 2017-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

/*  strict-local */
function _default(realm) {
  return build("Error", realm, false);
}

function describeLocation(realm, callerFn, env, loc) {
  let locString = "";
  let displayName = "";
  let key = loc || callerFn; // check if we've already encountered the callFn and if so
  // re-use that described location. plus we may get stuck trying
  // to get the location by recursively checking the same fun
  // so this also prevents a stack overflow

  if (key) {
    if (realm.alreadyDescribedLocations.has(key)) {
      return realm.alreadyDescribedLocations.get(key);
    }

    realm.alreadyDescribedLocations.set(key, undefined);
  }

  if (callerFn) {
    if (callerFn instanceof _index.NativeFunctionValue) {
      locString = "native";
    }

    let name = callerFn._SafeGetDataPropertyValue("name");

    if (!name.mightBeUndefined()) displayName = _singletons.To.ToStringPartial(realm, name);else name.throwIfNotConcrete();
    if (env && env.environmentRecord.$NewTarget) displayName = `new ${displayName}`;
  }

  if (!locString) {
    if (loc) {
      locString = `${loc.start.line}:${loc.start.column + 1}`;
      if (loc.source !== null) locString = `${loc.source}:${locString}`;
    } else {
      locString = (loc ? loc.source : undefined) || "unknown";
      if (!displayName) return undefined;
    }
  }

  let location;

  if (displayName) {
    location = `at ${displayName} (${locString})`;
  } else {
    location = `at ${locString}`;
  }

  if (key) {
    realm.alreadyDescribedLocations.set(key, location);
  }

  return location;
}

const buildStackTemplateSrc = 'A + (B ? ": " + B : "") + C';

function buildStack(realm, context) {
  (0, _invariant.default)(context.$ErrorData);
  let stack = context.$ErrorData.contextStack;
  if (!stack) return realm.intrinsics.undefined;
  let lines = [];

  let header = _singletons.To.ToStringPartial(realm, (0, _index2.Get)(realm, context, "name"));

  let message = (0, _index2.Get)(realm, context, "message");

  if (!message.mightBeUndefined()) {
    message = _singletons.To.ToStringValue(realm, message);
  } else {
    message.throwIfNotConcrete();
  }

  for (let executionContext of stack.reverse()) {
    let caller = executionContext.caller;
    if (!executionContext.loc) continue; // compiler generated helper for destructuring arguments

    let locString = describeLocation(realm, caller ? caller.function : undefined, caller ? caller.lexicalEnvironment : undefined, executionContext.loc);
    if (locString !== undefined) lines.push(locString);
  }

  let footer = `\n    ${lines.join("\n    ")}`;
  return message instanceof _index.StringValue ? new _index.StringValue(realm, `${header}${message.value ? `: ${message.value}` : ""}${footer}`) : _index.AbstractValue.createFromTemplate(realm, buildStackTemplateSrc, _index.StringValue, [new _index.StringValue(realm, header), message, new _index.StringValue(realm, footer)]);
}

function build(name, realm, inheritError = true) {
  let func = new _index.NativeFunctionValue(realm, name, name, 1, (context, [message], argLength, NewTarget) => {
    // 1. If NewTarget is undefined, let newTarget be the active function object, else let newTarget be NewTarget.
    let newTarget = NewTarget || func; // 2. Let O be ? OrdinaryCreateFromConstructor(newTarget, "%ErrorPrototype%", « [[ErrorData]] »).

    let O = _singletons.Create.OrdinaryCreateFromConstructor(realm, newTarget, `${name}Prototype`, {
      $ErrorData: undefined
    });

    O.$ErrorData = {
      contextStack: realm.contextStack.slice(1),
      locationData: undefined
    }; // 3. If message is not undefined, then

    if (!message.mightBeUndefined()) {
      // a. Let msg be ? ToString(message).
      let msg = message.getType() === _index.StringValue ? message : _singletons.To.ToStringValue(realm, message); // b. Let msgDesc be the PropertyDescriptor{[[Value]]: msg, [[Writable]]: true, [[Enumerable]]: false, [[Configurable]]: true}.

      let msgDesc = new _descriptors.PropertyDescriptor({
        value: msg,
        writable: true,
        enumerable: false,
        configurable: true
      }); // c. Perform ! DefinePropertyOrThrow(O, "message", msgDesc).

      _singletons.Properties.DefinePropertyOrThrow(realm, O, "message", msgDesc);
    } else {
      message.throwIfNotConcrete();
    } // Build a text description of the stack.


    let stackDesc = new _descriptors.PropertyDescriptor({
      value: buildStack(realm, O),
      enumerable: false,
      configurable: true,
      writable: true
    });

    _singletons.Properties.DefinePropertyOrThrow(realm, O, "stack", stackDesc); // 4. Return O.


    return O;
  });

  if (inheritError) {
    func.$Prototype = realm.intrinsics.Error;
  }

  return func;
}
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