make-built-in.js 2.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354
  1. var uncurryThis = require('../internals/function-uncurry-this');
  2. var fails = require('../internals/fails');
  3. var isCallable = require('../internals/is-callable');
  4. var hasOwn = require('../internals/has-own-property');
  5. var DESCRIPTORS = require('../internals/descriptors');
  6. var CONFIGURABLE_FUNCTION_NAME = require('../internals/function-name').CONFIGURABLE;
  7. var inspectSource = require('../internals/inspect-source');
  8. var InternalStateModule = require('../internals/internal-state');
  9. var enforceInternalState = InternalStateModule.enforce;
  10. var getInternalState = InternalStateModule.get;
  11. var $String = String;
  12. // eslint-disable-next-line es/no-object-defineproperty -- safe
  13. var defineProperty = Object.defineProperty;
  14. var stringSlice = uncurryThis(''.slice);
  15. var replace = uncurryThis(''.replace);
  16. var join = uncurryThis([].join);
  17. var CONFIGURABLE_LENGTH = DESCRIPTORS && !fails(function () {
  18. return defineProperty(function () { /* empty */ }, 'length', { value: 8 }).length !== 8;
  19. });
  20. var TEMPLATE = String(String).split('String');
  21. var makeBuiltIn = module.exports = function (value, name, options) {
  22. if (stringSlice($String(name), 0, 7) === 'Symbol(') {
  23. name = '[' + replace($String(name), /^Symbol\(([^)]*)\)/, '$1') + ']';
  24. }
  25. if (options && options.getter) name = 'get ' + name;
  26. if (options && options.setter) name = 'set ' + name;
  27. if (!hasOwn(value, 'name') || (CONFIGURABLE_FUNCTION_NAME && value.name !== name)) {
  28. if (DESCRIPTORS) defineProperty(value, 'name', { value: name, configurable: true });
  29. else value.name = name;
  30. }
  31. if (CONFIGURABLE_LENGTH && options && hasOwn(options, 'arity') && value.length !== options.arity) {
  32. defineProperty(value, 'length', { value: options.arity });
  33. }
  34. try {
  35. if (options && hasOwn(options, 'constructor') && options.constructor) {
  36. if (DESCRIPTORS) defineProperty(value, 'prototype', { writable: false });
  37. // in V8 ~ Chrome 53, prototypes of some methods, like `Array.prototype.values`, are non-writable
  38. } else if (value.prototype) value.prototype = undefined;
  39. } catch (error) { /* empty */ }
  40. var state = enforceInternalState(value);
  41. if (!hasOwn(state, 'source')) {
  42. state.source = join(TEMPLATE, typeof name == 'string' ? name : '');
  43. } return value;
  44. };
  45. // add fake Function#toString for correct work wrapped methods / constructors with methods like LoDash isNative
  46. // eslint-disable-next-line no-extend-native -- required
  47. Function.prototype.toString = makeBuiltIn(function toString() {
  48. return isCallable(this) && getInternalState(this).source || inspectSource(this);
  49. }, 'toString');