Add miksi js lib for build witness calculation

dist/miksi.js

@@ -0,0 +1,67 @@
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+const fs = require("fs");
+const { groth } = require('snarkjs');
+const { stringifyBigInts, unstringifyBigInts } = require('ffjavascript').utils;
+const WitnessCalculatorBuilder = require("circom_runtime").WitnessCalculatorBuilder;
+const circomlib = require("circomlib");
+const smt = require("circomlib").smt;
+const Web3 = require("web3");
+const nLevels = 5;
+const coinCode = "0"; // refearing to ETH
+const ethAmount = '1';
+const amount = Web3.utils.toWei(ethAmount, 'ether');
+exports.calcWitness = (wasm, secret, nullifier, commitments) => __awaiter(this, void 0, void 0, function* () {
+    const poseidon = circomlib.poseidon.createHash(6, 8, 57);
+    const commitment = poseidon([coinCode, amount, secret, nullifier]).toString();
+    let tree = yield smt.newMemEmptyTrie();
+    yield tree.insert(1, 0);
+    // old root
+    const rootOld = tree.root;
+    const resOld = yield tree.find(commitment);
+    if (resOld.found) {
+        console.error("leaf expect to not exist but exists");
+    }
+    let siblingsOld = resOld.siblings;
+    while (siblingsOld.length < nLevels) {
+        siblingsOld.push("0");
+    }
+    ;
+    yield tree.insert(commitment, 0);
+    // new root
+    const rootNew = tree.root;
+    const resNew = yield tree.find(commitment);
+    if (!resNew.found) {
+        console.error("leaf expect to exist but not exists");
+    }
+    let siblingsNew = resNew.siblings;
+    while (siblingsNew.length < nLevels) {
+        siblingsNew.push("0");
+    }
+    ;
+    // calculate witness
+    const input = unstringifyBigInts({
+        "coinCode": coinCode,
+        "amount": amount,
+        "secret": secret,
+        "nullifier": nullifier,
+        "siblingsOld": siblingsOld,
+        "siblingsNew": siblingsNew,
+        "rootOld": rootOld,
+        "rootNew": rootNew,
+        "commitment": commitment
+    });
+    const options = {};
+    const wc = yield WitnessCalculatorBuilder(wasm, options);
+    const w = yield wc.calculateWitness(input);
+    const witness = unstringifyBigInts(stringifyBigInts(w));
+    return witness;
+});
+//# sourceMappingURL=miksi.js.map