circomlib/test/smtverifier.js

const chai = require("chai");
const path = require("path");
const snarkjs = require("snarkjs");
const compiler = require("circom");

const smt = require("../src/smt.js");

const assert = chai.assert;

const bigInt = snarkjs.bigInt;

function print(circuit, w, s) {
    console.log(s + ": " + w[circuit.getSignalIdx(s)]);
}

async function testInclusion(tree, key, circuit) {

    const res = await tree.find(key);

    assert(res.found);
    let siblings = res.siblings;
    while (siblings.length<10) siblings.push(bigInt(0));

    const w = circuit.calculateWitness({
        enabled: 1,
        fnc: 0,
        root: tree.root,
        siblings: siblings,
        oldKey: 0,
        oldValue: 0,
        isOld0: 0,
        key: key,
        value: res.foundValue
    });

    assert(circuit.checkWitness(w));
}

async function testExclusion(tree, key, circuit) {
    const res = await tree.find(key);

    assert(!res.found);
    let siblings = res.siblings;
    while (siblings.length<10) siblings.push(bigInt(0));

    const w = circuit.calculateWitness({
        enabled: 1,
        fnc: 1,
        root: tree.root,
        siblings: siblings,
        oldKey: res.isOld0 ? 0 : res.notFoundKey,
        oldValue: res.isOld0 ? 0 : res.notFoundValue,
        isOld0: res.isOld0 ? 1 : 0,
        key: key,
        value: 0
    });

    assert(circuit.checkWitness(w));
}

describe("SMT test", function () {
    let circuit;
    let tree;

    this.timeout(100000);

    before( async () => {
        const cirDef = await compiler(path.join(__dirname, "circuits", "smtverifier10_test.circom"));

        circuit = new snarkjs.Circuit(cirDef);

        console.log("NConstrains SMTVerifier: " + circuit.nConstraints);

        tree = await smt.newMemEmptyTrie();
        await tree.insert(7,77);
        await tree.insert(8,88);
        await tree.insert(32,3232);
    });

    it("Check inclussion in a tree of 3", async () => {
        await testInclusion(tree, 7, circuit);
        await testInclusion(tree, 8, circuit);
        await testInclusion(tree, 32, circuit);
    });

    it("Check exclussion in a tree of 3", async () => {
        await testExclusion(tree, 0, circuit);
        await testExclusion(tree, 6, circuit);
        await testExclusion(tree, 9, circuit);
        await testExclusion(tree, 33, circuit);
        await testExclusion(tree, 31, circuit);
        await testExclusion(tree, 16, circuit);
        await testExclusion(tree, 64, circuit);
    });

    it("Check not enabled accepts any thing", async () => {
        let siblings = [];
        for (let i=0; i<10; i++) siblings.push(i);

        const w = circuit.calculateWitness({
            enabled: 0,
            fnc: 0,
            root: 1,
            siblings: siblings,
            oldKey: 22,
            oldValue: 33,
            isOld0: 0,
            key: 44,
            value: 0
        });
        assert(circuit.checkWitness(w));
    });


});