24 lines
721 B
JavaScript
Executable file
24 lines
721 B
JavaScript
Executable file
'use strict';
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var anObject = require('../internals/an-object');
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// `Map.prototype.upsert` method
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// https://github.com/thumbsupep/proposal-upsert
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module.exports = function upsert(key, updateFn /* , insertFn */) {
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var map = anObject(this);
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var insertFn = arguments.length > 2 ? arguments[2] : undefined;
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var value;
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if (typeof updateFn != 'function' && typeof insertFn != 'function') {
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throw TypeError('At least one callback required');
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}
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if (map.has(key)) {
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value = map.get(key);
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if (typeof updateFn == 'function') {
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value = updateFn(value);
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map.set(key, value);
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}
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} else if (typeof insertFn == 'function') {
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value = insertFn();
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map.set(key, value);
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} return value;
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};
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