51 lines
1.0 KiB
JavaScript
51 lines
1.0 KiB
JavaScript
'use strict';
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const mimicFn = require('mimic-fn');
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const calledFunctions = new WeakMap();
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const oneTime = (fn, options = {}) => {
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if (typeof fn !== 'function') {
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throw new TypeError('Expected a function');
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}
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let ret;
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let isCalled = false;
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let callCount = 0;
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const functionName = fn.displayName || fn.name || '<anonymous>';
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const onetime = function (...args) {
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calledFunctions.set(onetime, ++callCount);
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if (isCalled) {
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if (options.throw === true) {
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throw new Error(`Function \`${functionName}\` can only be called once`);
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}
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return ret;
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}
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isCalled = true;
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ret = fn.apply(this, args);
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fn = null;
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return ret;
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};
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mimicFn(onetime, fn);
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calledFunctions.set(onetime, callCount);
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return onetime;
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};
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module.exports = oneTime;
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// TODO: Remove this for the next major release
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module.exports.default = oneTime;
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module.exports.callCount = fn => {
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if (!calledFunctions.has(fn)) {
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throw new Error(`The given function \`${fn.name}\` is not wrapped by the \`onetime\` package`);
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}
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return calledFunctions.get(fn);
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};
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