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1
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'use strict';
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2
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3
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var callBound = require('../helpers/callBound');
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4
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5
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var $PromiseThen = callBound('Promise.prototype.then', true);
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6
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7
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var Type = require('./Type');
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8
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9
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// https://www.ecma-international.org/ecma-262/6.0/#sec-ispromise
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10
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11
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module.exports = function IsPromise(x) {
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12
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if (Type(x) !== 'Object') {
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13
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return false;
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14
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}
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15
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if (!$PromiseThen) { // Promises are not supported
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16
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return false;
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17
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}
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18
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try {
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19
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$PromiseThen(x); // throws if not a promise
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20
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} catch (e) {
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21
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return false;
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22
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}
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23
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return true;
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24
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};
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