es.promise.finally.js 1.7 KB

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  1. 'use strict';
  2. var $ = require('../internals/export');
  3. var IS_PURE = require('../internals/is-pure');
  4. var NativePromise = require('../internals/native-promise-constructor');
  5. var fails = require('../internals/fails');
  6. var getBuiltIn = require('../internals/get-built-in');
  7. var isCallable = require('../internals/is-callable');
  8. var speciesConstructor = require('../internals/species-constructor');
  9. var promiseResolve = require('../internals/promise-resolve');
  10. var redefine = require('../internals/redefine');
  11. // Safari bug https://bugs.webkit.org/show_bug.cgi?id=200829
  12. var NON_GENERIC = !!NativePromise && fails(function () {
  13. NativePromise.prototype['finally'].call({ then: function () { /* empty */ } }, function () { /* empty */ });
  14. });
  15. // `Promise.prototype.finally` method
  16. // https://tc39.es/ecma262/#sec-promise.prototype.finally
  17. $({ target: 'Promise', proto: true, real: true, forced: NON_GENERIC }, {
  18. 'finally': function (onFinally) {
  19. var C = speciesConstructor(this, getBuiltIn('Promise'));
  20. var isFunction = isCallable(onFinally);
  21. return this.then(
  22. isFunction ? function (x) {
  23. return promiseResolve(C, onFinally()).then(function () { return x; });
  24. } : onFinally,
  25. isFunction ? function (e) {
  26. return promiseResolve(C, onFinally()).then(function () { throw e; });
  27. } : onFinally
  28. );
  29. }
  30. });
  31. // makes sure that native promise-based APIs `Promise#finally` properly works with patched `Promise#then`
  32. if (!IS_PURE && isCallable(NativePromise)) {
  33. var method = getBuiltIn('Promise').prototype['finally'];
  34. if (NativePromise.prototype['finally'] !== method) {
  35. redefine(NativePromise.prototype, 'finally', method, { unsafe: true });
  36. }
  37. }