snarkyjs Poseidon test

poseidon_test.ts

import {
    Poseidon,
    Field,
    Circuit,
    circuitMain,
    public_,
    isReady,
    CircuitValue,
    arrayProp,
  } from 'snarkyjs';
  
  /* Exercise 0:
  
  Public input: a hash value h
  Prove:
    I know a value x such that hash(x) = h 
  */
  
  // count is how many Field elements to hash. 1 element's size is 32 bytes 
  const count = 1024;

    class TwoFields extends CircuitValue {
      @arrayProp(Field, count) fields: Field[];
    
      constructor(fields: Field[]) {
        super();
        this.fields = fields;
      }
    }
    
    class Main extends Circuit {
      @circuitMain
      static main(preimage: TwoFields, @public_ hash: Field) {
        Poseidon.hash(preimage.fields).assertEquals(hash);
      }
    }
    
  
  await isReady;
  
  console.log('generating keypair...');
  const kp = Main.generateKeypair();
  
  const preimage = new TwoFields(Array(count).fill(Field.one));
  const hash = Poseidon.hash(preimage.fields);
  
  console.log('prove...');
  console.time('prove');
  const pi = Main.prove([preimage], [hash], kp);
  console.timeEnd('prove');
  console.log('proof', pi);
  
  console.log('verify...');
  let ok = Main.verify([hash], kp.verificationKey(), pi);
  console.log('ok?', ok);
  

// use nodejs version >= 16.5
// nvm use 16.5

git clone https://github.com/o1-labs/snarkyjs
cd snarkyjs
// copy poseidon_test.ts into src/examples/
npm install
npm run build
./run src/examples/poseidon_test.ts
// adjust count on line 20 to hash more/less data