the full script for the instructive page here: https://noir-lang.org/typescript

typescript_bbjs.ts

import circuit from '../target/test.json' assert { type: 'json' };
import { decompressSync } from 'fflate';
import { Crs, newBarretenbergApiAsync, RawBuffer } from '@aztec/bb.js/dest/node/index.js';
import { ethers } from 'ethers'; // I'm lazy so I'm using ethers to pad my input
import { executeCircuit, compressWitness } from '@noir-lang/acvm_js';

async function main() {

    const acirBuffer = Buffer.from(circuit.bytecode, 'base64');
    const acirBufferUncompressed = decompressSync(acirBuffer);

    const api = await newBarretenbergApiAsync(4);

    const [exact, circuitSize, subgroup] = await api.acirGetCircuitSizes(acirBufferUncompressed);
    const subgroupSize = Math.pow(2, Math.ceil(Math.log2(circuitSize)));
    const crs = await Crs.new(subgroupSize + 1);
    await api.commonInitSlabAllocator(subgroupSize);
    await api.srsInitSrs(new RawBuffer(crs.getG1Data()), crs.numPoints, new RawBuffer(crs.getG2Data()));

    const acirComposer = await api.acirNewAcirComposer(subgroupSize);

    async function generateWitness(input: any, acirBuffer: Buffer): Promise<Uint8Array> {
        const initialWitness = new Map<number, string>();
        initialWitness.set(1, ethers.utils.hexZeroPad(`0x${input.x.toString(16)}`, 32));
        initialWitness.set(2, ethers.utils.hexZeroPad(`0x${input.y.toString(16)}`, 32));
        // initialWitness.set(3, ethers.utils.hexZeroPad(`0x${input.z.toString(16)}`, 32));

        const witnessMap = await executeCircuit(acirBuffer, initialWitness, () => {
            throw Error('unexpected oracle');
        });

        const witnessBuff = compressWitness(witnessMap);
        return witnessBuff;
    }

    async function generateProof(witness: Uint8Array) {
        const proof = await api.acirCreateProof(
            acirComposer,
            acirBufferUncompressed,
            decompressSync(witness),
            false,
        );
        return proof;
    }

    async function verifyProof(proof: Uint8Array) {
        await api.acirInitProvingKey(acirComposer, acirBufferUncompressed);
        const verified = await api.acirVerifyProof(acirComposer, proof, false);
        return verified;
    }

    const input = { x: 3, y: 4 };
    const witness = await generateWitness(input, acirBuffer);
    console.log('Witness generated!');
    const proof = await generateProof(witness);
    console.log('Proof generated!');
    await verifyProof(proof);
    console.log('Proof verified!');
    api.destroy();
}

main();

I have changed the circuit as follows:

fn main(x: Field, y: pub Field) -> pub Field{
    let z = std::hash::pedersen([x,y])[0];
    assert(z == std::hash::pedersen([x,y])[0]);
    z
}

Then I run the code and print witnessMap. I received:

I think witness size of pedersen hash should be bigger. Where am I wrong? I read the noir book, but I still don't understand how you create constraints? I want my code to prove that the pedersen hash of x and y is calculated correctly in noir.

i think that's right actually. you can see that value 3 and 5 match and 4 and 6 match. This is what i get when i calculate the pedersen hash in noir.

["0x25ed48b406cb7ac716062c45023b0523f5ed4e9a0baa12876fdc70307a8ad2f5", "0x0c290c796ea74cf713eaa3e74f2afdbffff95bd128dc77c02fce10cc479dfd0a"]

I used to work with SnarkJS and Circom. I noticed that the witness size of the Pedersen hash is much larger compared to here. I wonder how all the constraints can be covered with a witness like this.
Looking at the above, I can see that my code doesn't generate constraints during the Pedersen hash calculation process; it only calculates the Pedersen hash first and then creates constraints afterward.
During the proof generation process, does Noir cover all the constraints?

Yes, noir will cover all of the constraints defined in the circuit during the proof generation process. I don't think the pedersen hash calculation requires generating constrains, you only really care about constraining the result, no?

I keep getting this error, from inside the node_modules after setting up tsconfig and package.json as provided in the tutorial here: https://noir-lang.org/typescript

`npx tsc index.ts
index.ts:1:21 - error TS2732: Cannot find module './target/MyCircuit.json'. Consider using '--resolveJsonModule' to import module with '.json' extension.

1 import circuit from "./target/MyCircuit.json" assert { type: "json" };
~~~~~~~~~~~~~~~~~~~~~~~~~

index.ts:1:47 - error TS2821: Import assertions are only supported when the '--module' option is set to 'esnext' or 'nodenext'.

1 import circuit from "./target/MyCircuit.json" assert { type: "json" };
~~~~~~~~~~~~~~~~~~~~~~~

node_modules/@aztec/bb.js/dest/node/barretenberg_wasm/barretenberg_wasm.d.ts:1:23 - error TS1452: 'resolution-mode' assertions are only supported when moduleResolution is node16 or nodenext.

1 ///
~~~~

node_modules/@aztec/bb.js/dest/node/types/node/point.d.ts:1:23 - error TS1452: 'resolution-mode' assertions are only supported when moduleResolution is node16 or nodenext.

1 ///
~~~~

Found 4 errors in 3 files.

Errors Files
2 index.ts:1
1 node_modules/@aztec/bb.js/dest/node/barretenberg_wasm/barretenberg_wasm.d.ts:1
1 node_modules/@aztec/bb.js/dest/node/types/node/point.d.ts:1
`

---

tsconfig: https://gist.github.com/critesjosh/6f3ba19fdc9298b24e90ba4f736247dc

package.json:

{ "name": "mycircuit", "version": "1.0.0", "type": "module", "description": "", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "keywords": [], "author": "", "license": "ISC", "devDependencies": { "@types/node": "^20.8.6", "typescript": "^5.2.2" }, "dependencies": { "@aztec/bb.js": "^0.3.6", "@noir-lang/acvm_js": "git+https://[email protected]/noir-lang/acvm-simulator-wasm.git#b9d9ca9dfc5140839f23998d9466307215607c42", "ethers": "^5.7.2", "fflate": "^0.8.1" } }

@infinitywarp I recommend trying this new guide: https://noir-lang.org/dev/noir_js/getting_started/tiny_noir_app