circomlib/test/smtjs.js

const chai = require("chai");
const snarkjs = require("snarkjs");

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

const assert = chai.assert;

const bigInt = snarkjs.bigInt;


function stringifyBigInts(o) {
    if ((typeof(o) == "bigint") || (o instanceof bigInt))  {
        return o.toString(10);
    } else if (Array.isArray(o)) {
        return o.map(stringifyBigInts);
    } else if (typeof o == "object") {
        const res = {};
        for (let k in o) {
            res[k] = stringifyBigInts(o[k]);
        }
        return res;
    } else {
        return o;
    }
}

describe("SMT Javascript test", function () {
    this.timeout(100000);
    before( async () => {
    });

    it("Should insert 2 elements and empty them", async () => {
        const tree = await smt.newMemEmptyTrie();
        const key1 = bigInt(111);
        const value1 = bigInt(222);
        const key2 = bigInt(333);
        const value2 = bigInt(444);

        await tree.insert(key1,value1);
        await tree.insert(key2,value2);
        await tree.delete(key2);
        await tree.delete(key1);

        assert(tree.root.isZero());
    });

    it("Should insert 3 elements in dferent order and should be the same", async () => {
        const keys = [bigInt(8), bigInt(9), bigInt(32)];
        const values = [bigInt(88), bigInt(99), bigInt(3232)];
        const tree1 = await smt.newMemEmptyTrie();
        const tree2 = await smt.newMemEmptyTrie();
        const tree3 = await smt.newMemEmptyTrie();
        const tree4 = await smt.newMemEmptyTrie();
        const tree5 = await smt.newMemEmptyTrie();
        const tree6 = await smt.newMemEmptyTrie();

        await tree1.insert(keys[0],values[0]);
        await tree1.insert(keys[1],values[1]);
        await tree1.insert(keys[2],values[2]);

        await tree2.insert(keys[0],values[0]);
        await tree2.insert(keys[2],values[2]);
        await tree2.insert(keys[1],values[1]);

        await tree3.insert(keys[1],values[1]);
        await tree3.insert(keys[0],values[0]);
        await tree3.insert(keys[2],values[2]);

        await tree4.insert(keys[1],values[1]);
        await tree4.insert(keys[2],values[2]);
        await tree4.insert(keys[0],values[0]);

        await tree5.insert(keys[2],values[2]);
        await tree5.insert(keys[0],values[0]);
        await tree5.insert(keys[1],values[1]);

        await tree6.insert(keys[2],values[2]);
        await tree6.insert(keys[1],values[1]);
        await tree6.insert(keys[0],values[0]);

        assert(tree1.root.equals(tree2.root));
        assert(tree2.root.equals(tree3.root));
        assert(tree3.root.equals(tree4.root));
        assert(tree4.root.equals(tree5.root));
        assert(tree5.root.equals(tree6.root));

        assert.equal(Object.keys(tree1.db.nodes).length,  Object.keys(tree2.db.nodes).length);
        assert.equal(Object.keys(tree2.db.nodes).length,  Object.keys(tree3.db.nodes).length);
        assert.equal(Object.keys(tree3.db.nodes).length,  Object.keys(tree4.db.nodes).length);
        assert.equal(Object.keys(tree4.db.nodes).length,  Object.keys(tree5.db.nodes).length);
        assert.equal(Object.keys(tree5.db.nodes).length,  Object.keys(tree6.db.nodes).length);

        await tree1.delete(keys[0]);
        await tree1.delete(keys[1]);
        await tree2.delete(keys[1]);
        await tree2.delete(keys[0]);
        assert(tree1.root.equals(tree2.root));

        await tree3.delete(keys[0]);
        await tree3.delete(keys[2]);
        await tree4.delete(keys[2]);
        await tree4.delete(keys[0]);
        assert(tree3.root.equals(tree4.root));

        await tree5.delete(keys[1]);
        await tree5.delete(keys[2]);
        await tree6.delete(keys[2]);
        await tree6.delete(keys[1]);
        assert(tree5.root.equals(tree6.root));

        await tree1.delete(keys[2]);
        await tree2.delete(keys[2]);
        await tree3.delete(keys[1]);
        await tree4.delete(keys[1]);
        await tree5.delete(keys[0]);
        await tree6.delete(keys[0]);

        assert(tree1.root.isZero());
        assert(tree2.root.isZero());
        assert(tree3.root.isZero());
        assert(tree4.root.isZero());
        assert(tree5.root.isZero());
        assert(tree6.root.isZero());

        assert.equal(Object.keys(tree1.db.nodes).length, 0);
        assert.equal(Object.keys(tree2.db.nodes).length, 0);
        assert.equal(Object.keys(tree3.db.nodes).length, 0);
        assert.equal(Object.keys(tree4.db.nodes).length, 0);
        assert.equal(Object.keys(tree5.db.nodes).length, 0);
        assert.equal(Object.keys(tree6.db.nodes).length, 0);
    });

    it("Insert and remove 100 numbers randomly", async () => {
        function perm(a) {
            const arr = a.slice();
            const rArr = [];
            for (let i=0; i<arr.length; i++) {
                let rIdx = Math.floor(Math.random() * (arr.length - i));
                rArr.push(arr[rIdx]);
                arr[rIdx] = arr[arr.length - i - 1];
            }
            return rArr;
        }
        const tree = await smt.newMemEmptyTrie();
        const arr = [];
        const N = 100;
        for (let i=0; i<N; i++) {
            arr.push(bigInt(i));
        }
        const insArr = perm(arr);
        for (let i=0; i<N; i++) {
            await tree.insert(insArr[i], i);
        }
        const delArr = perm(insArr);
        for (let i=0; i<N; i++) {
            await tree.delete(delArr[i]);
        }

        assert(tree.root.isZero());
        assert.equal(Object.keys(tree.db.nodes).length, 0);
    });

    it("Should test update", async () => {
        const tree1 = await smt.newMemEmptyTrie();
        const tree2 = await smt.newMemEmptyTrie();

        await tree1.insert(8,88);
        await tree1.insert(9,99,);
        await tree1.insert(32,3232);

        await tree2.insert(8,888);
        await tree2.insert(9,999);
        await tree2.insert(32,323232);

        await tree1.update(8, 888);
        await tree1.update(9, 999);
        await tree1.update(32, 323232);

        assert(tree1.root.equals(tree2.root));
    });

});