1const chai = require("chai");
  2const assert = chai.assert;
  3
  4const fs = require("fs");
  5var tmp = require("tmp-promise");
  6const path = require("path");
  7const compiler = require("../../src/compiler");
  8
  9const bigInt = require("big-integer");
 10const utils = require("../../src/utils");
 11const loadR1cs = require("r1csfile").load;
 12const ZqField = require("ffjavascript").ZqField;
 13
 14const WitnessCalculatorBuilder = require("circom_runtime").WitnessCalculatorBuilder;
 15
 16module.exports = wasm_tester;
 17
 18async function  wasm_tester(circomFile, _options) {
 19    tmp.setGracefulCleanup();
 20
 21    const dir = await tmp.dir({prefix: "circom_", unsafeCleanup: true });
 22
 23    // console.log(dir.path);
 24
 25    const baseName = path.basename(circomFile, ".circom");
 26    const options = Object.assign({}, _options);
 27
 28    options.wasmWriteStream = fs.createWriteStream(path.join(dir.path, baseName + ".wasm"));
 29    options.symWriteStream = fs.createWriteStream(path.join(dir.path, baseName + ".sym"));
 30    options.r1csFileName = path.join(dir.path, baseName + ".r1cs");
 31
 32    const promisesArr = [];
 33    promisesArr.push(new Promise(fulfill => options.wasmWriteStream.on("finish", fulfill)));
 34
 35    await compiler(circomFile, options);
 36
 37    await Promise.all(promisesArr);
 38
 39    const wasm = await fs.promises.readFile(path.join(dir.path, baseName + ".wasm"));
 40
 41    const wc = await WitnessCalculatorBuilder(wasm);
 42
 43    return new WasmTester(dir, baseName, wc);
 44}
 45
 46class WasmTester {
 47
 48    constructor(dir, baseName, witnessCalculator) {
 49        this.dir=dir;
 50        this.baseName = baseName;
 51        this.witnessCalculator = witnessCalculator;
 52    }
 53
 54    async release() {
 55        await this.dir.cleanup();
 56    }
 57
 58    async calculateWitness(input) {
 59
 60        return await this.witnessCalculator.calculateWitness(input);
 61    }
 62
 63    async loadSymbols() {
 64        if (this.symbols) return;
 65        this.symbols = {};
 66        const symsStr = await fs.promises.readFile(
 67            path.join(this.dir.path, this.baseName + ".sym"),
 68            "utf8"
 69        );
 70        const lines = symsStr.split("\n");
 71        for (let i=0; i<lines.length; i++) {
 72            const arr = lines[i].split(",");
 73            if (arr.length!=4) continue;
 74            this.symbols[arr[3]] = {
 75                labelIdx: Number(arr[0]),
 76                varIdx: Number(arr[1]),
 77                componentIdx: Number(arr[2]),
 78            };
 79        }
 80    }
 81
 82    async loadConstraints() {
 83        const self = this;
 84        if (this.constraints) return;
 85        const r1cs = await loadR1cs(path.join(this.dir.path, this.baseName + ".r1cs"),true, false);
 86        self.field = new ZqField(r1cs.prime);
 87        self.nVars = r1cs.nVars;
 88        self.constraints = r1cs.constraints;
 89    }
 90
 91    async assertOut(actualOut, expectedOut) {
 92        const self = this;
 93        if (!self.symbols) await self.loadSymbols();
 94
 95        checkObject("main", expectedOut);
 96
 97        function checkObject(prefix, eOut) {
 98
 99            if (Array.isArray(eOut)) {
100                for (let i=0; i<eOut.length; i++) {
101                    checkObject(prefix + "["+i+"]", eOut[i]);
102                }
103            } else if ((typeof eOut == "object")&&(eOut.constructor.name == "Object")) {
104                for (let k in eOut) {
105                    checkObject(prefix + "."+k, eOut[k]);
106                }
107            } else {
108                if (typeof self.symbols[prefix] == "undefined") {
109                    assert(false, "Output variable not defined: "+ prefix);
110                }
111                const ba = bigInt(actualOut[self.symbols[prefix].varIdx]).toString();
112                const be = bigInt(eOut).toString();
113                assert.strictEqual(ba, be, prefix);
114            }
115        }
116    }
117
118    async getDecoratedOutput(witness) {
119        const self = this;
120        const lines = [];
121        if (!self.symbols) await self.loadSymbols();
122        for (let n in self.symbols) {
123            let v;
124            if (utils.isDefined(witness[self.symbols[n].varIdx])) {
125                v = witness[self.symbols[n].varIdx].toString();
126            } else {
127                v = "undefined";
128            }
129            lines.push(`${n} --> ${v}`);
130        }
131        return lines.join("\n");
132    }
133
134    async checkConstraints(witness) {
135        const self = this;
136        if (!self.constraints) await self.loadConstraints();
137        for (let i=0; i<self.constraints.length; i++) {
138            checkConstraint(self.constraints[i]);
139        }
140
141        function checkConstraint(constraint) {
142            const F = self.field;
143            const a = evalLC(constraint[0]);
144            const b = evalLC(constraint[1]);
145            const c = evalLC(constraint[2]);
146
147            assert (F.sub(F.mul(a,b), c).isZero(), "Constraint doesn't match");
148        }
149
150        function evalLC(lc) {
151            const F = self.field;
152            let v = F.zero;
153            for (let w in lc) {
154                v = F.add(
155                    v,
156                    F.mul( lc[w], witness[w] )
157                );
158            }
159            return v;
160        }
161    }
162
163}
164
165