fast-check/lib/check/arbitrary/FrequencyArbitrary.js

Property based testing framework for JavaScript (like QuickCheck)

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.frequency = void 0;
const Arbitrary_1 = require("./definition/Arbitrary");
class FrequencyArbitrary extends Arbitrary_1.Arbitrary {
    constructor(warbs) {
        super();
        this.warbs = warbs;
        let currentWeight = 0;
        this.summedWarbs = [];
        for (let idx = 0; idx !== warbs.length; ++idx) {
            currentWeight += warbs[idx].weight;
            this.summedWarbs.push({ weight: currentWeight, arbitrary: warbs[idx].arbitrary });
        }
        this.totalWeight = currentWeight;
    }
    generate(mrng) {
        const selected = mrng.nextInt(0, this.totalWeight - 1);
        for (let idx = 0; idx !== this.summedWarbs.length; ++idx) {
            if (selected < this.summedWarbs[idx].weight)
                return this.summedWarbs[idx].arbitrary.generate(mrng);
        }
        throw new Error(`Unable to generate from fc.frequency`);
    }
    withBias(freq) {
        return new FrequencyArbitrary(this.warbs.map((v) => ({ weight: v.weight, arbitrary: v.arbitrary.withBias(freq) })));
    }
}
function frequency(...warbs) {
    if (warbs.length === 0) {
        throw new Error('fc.frequency expects at least one parameter');
    }
    return new FrequencyArbitrary([...warbs]);
}
exports.frequency = frequency;