| 'use strict'; |
| |
| var $TypeError = require('es-errors/type'); |
| var isObject = require('es-object-atoms/isObject'); |
| |
| var Call = require('./Call'); |
| var CompletionRecord = require('./CompletionRecord'); |
| var GetMethod = require('./GetMethod'); |
| var IsCallable = require('./IsCallable'); |
| |
| var isIteratorRecord = require('../helpers/records/iterator-record'); |
| |
| // https://262.ecma-international.org/15.0/#sec-iteratorclose |
| |
| module.exports = function IteratorClose(iteratorRecord, completion) { |
| if (!isIteratorRecord(iteratorRecord)) { |
| throw new $TypeError('Assertion failed: `iteratorRecord` must be an Iterator Record'); // step 1 |
| } |
| if (!isObject(iteratorRecord['[[Iterator]]'])) { |
| throw new $TypeError('Assertion failed: iteratorRecord.[[Iterator]] must be an Object'); // step 1 |
| } |
| |
| if (!IsCallable(completion) && !(completion instanceof CompletionRecord)) { // step 2 |
| throw new $TypeError('Assertion failed: completion is not a thunk representing a Completion Record, nor a Completion Record instance'); |
| } |
| var completionThunk = completion instanceof CompletionRecord ? function () { return completion['?'](); } : completion; |
| |
| var iterator = iteratorRecord['[[Iterator]]']; // step 3 |
| |
| var iteratorReturn; |
| try { |
| iteratorReturn = GetMethod(iterator, 'return'); // step 4 |
| } catch (e) { |
| completionThunk(); // throws if `completion` is a throw completion // step 6 |
| completionThunk = null; // ensure it's not called twice. |
| throw e; // step 7 |
| } |
| if (typeof iteratorReturn === 'undefined') { |
| return completionThunk(); // step 5.a - 5.b |
| } |
| |
| var innerResult; |
| try { |
| innerResult = Call(iteratorReturn, iterator, []); |
| } catch (e) { |
| // if we hit here, then "e" is the innerResult completion that needs re-throwing |
| |
| completionThunk(); // throws if `completion` is a throw completion // step 6 |
| completionThunk = null; // ensure it's not called twice. |
| |
| // if not, then return the innerResult completion |
| throw e; // step 7 |
| } |
| var completionRecord = completionThunk(); // if innerResult worked, then throw if the completion does |
| completionThunk = null; // ensure it's not called twice. |
| |
| if (!isObject(innerResult)) { |
| throw new $TypeError('iterator .return must return an object'); |
| } |
| |
| return completionRecord; |
| }; |