fast-check/lib/esm/check/arbitrary/DedupArbitrary.js

Property based testing framework for JavaScript (like QuickCheck)

import { stream } from '../../stream/Stream.js';
import { cloneMethod } from '../symbols.js';
import { Arbitrary } from './definition/Arbitrary.js';
import { Shrinkable } from './definition/Shrinkable.js';
class DedupArbitrary extends Arbitrary {
    constructor(arb, numValues) {
        super();
        this.arb = arb;
        this.numValues = numValues;
    }
    generate(mrng) {
        const items = [];
        if (this.numValues <= 0) {
            return this.wrapper(items);
        }
        for (let idx = 0; idx !== this.numValues - 1; ++idx) {
            items.push(this.arb.generate(mrng.clone()));
        }
        items.push(this.arb.generate(mrng));
        return this.wrapper(items);
    }
    static makeItCloneable(vs, shrinkables) {
        vs[cloneMethod] = () => {
            const cloned = [];
            for (let idx = 0; idx !== shrinkables.length; ++idx) {
                cloned.push(shrinkables[idx].value);
            }
            this.makeItCloneable(cloned, shrinkables);
            return cloned;
        };
        return vs;
    }
    wrapper(items) {
        let cloneable = false;
        const vs = [];
        for (let idx = 0; idx !== items.length; ++idx) {
            const s = items[idx];
            cloneable = cloneable || s.hasToBeCloned;
            vs.push(s.value);
        }
        if (cloneable) {
            DedupArbitrary.makeItCloneable(vs, items);
        }
        return new Shrinkable(vs, () => stream(this.shrinkImpl(items)).map((v) => this.wrapper(v)));
    }
    *shrinkImpl(items) {
        if (items.length === 0) {
            return;
        }
        const its = items.map((s) => s.shrink()[Symbol.iterator]());
        let cur = its.map((it) => it.next());
        while (!cur[0].done) {
            yield cur.map((c) => c.value);
            cur = its.map((it) => it.next());
        }
    }
}
function dedup(arb, numValues) {
    return new DedupArbitrary(arb, numValues);
}
export { dedup };