I have been trying to add to write my own basic tests for a chainlink oracle response. I am adding these tests to Ampleforth's test folder. However, the tests I am running are for the moment very basic.

I am trying to deploy a contract using hardhat - which currently works - and then test a basic function to see if it outputs a number.

This is my test:

import { ethers, upgrades, waffle } from 'hardhat'
import { Contract, Signer, BigNumber, BigNumberish, Event } from 'ethers'
import { TransactionResponse } from '@ethersproject/providers'
import { expect } from 'chai'
import { Result } from 'ethers/lib/utils'
import { imul, increaseTime } from '../utils/utils'

let oracleAPI: Contract
// let oracleAPI: Contract
let mockMarketOracle: Contract
let prevEpoch: BigNumber, prevTime: BigNumber
let deployer: Signer, user: Signer, orchestrator: Signer

console.log("checking test is ran");

async function setupOracle() { 
    console.log("checking setup is ran");
    const [deployer, user, orchestrator] = await ethers.getSigners()
    console.log("got ethers ", deployer);
    oracleAPI = await (await ethers.getContractFactory('APIConsumer'))
    await oracleAPI.deployed();

    // return mockMarketOracle;
describe('my API tests', function () { 
    before('setting up my API oracle', async () => { 
        await waffle.loadFixture(setupOracle);
        console.log("tx13 ");

    it('not sure what this should do', async function () {
        console.log("tx12 ", oracleAPI);
        // console.log("tx14");
        // console.log( await oracleAPI.testPrint());
        expect( (await oracleAPI.testPrint()) ).to.eq(100);

        const testNumb = await oracleAPI.setPrint(20); 

        await oracleAPI.wait();

        expect( await testNumb ).to.equal(20);
        // console.log("did this print?");

The only functions I am testing are:

function testPrint() public returns (uint256) {
    return incomeIndex;

function setPrint(uint256 t) public returns (uint256) {
    test = t;
    return test;

At the tx12 print statement it outputs a contract json with all of the functions, so I am not sure what is going on. I get this error:

1) my API tests
   not sure what this should do:
 AssertionError: expected { Object (hash, type, ...) } to equal 100
  at Context.<anonymous> (test\unit\OracleApiTest.ts:39:52)
  at step (test\unit\OracleApiTest.ts:33:23)
  at Object.next (test\unit\OracleApiTest.ts:14:53)
  at fulfilled (test\unit\OracleApiTest.ts:5:58)
  at processTicksAndRejections (node:internal/process/task_queues:96:5)
  at runNextTicks (node:internal/process/task_queues:65:3)
  at listOnTimeout (node:internal/timers:526:9)
  at processTimers (node:internal/timers:500:7)

Which suggests it's still just looking at the raw contract json object and not waiting for the function call to resolve. Can anyone help?

1 Answer 1

  1. You should either mark testPrint() as a view function
function testPrint() public view returns (uint256) {
    return incomeIndex;

and then call

expect( (await oracleAPI.testPrint()) ).to.eq(100);


  1. Leave the testPrint() function as it is now and then in your tests call
expect( (await oracleAPI.callStatic.testPrint()) ).to.eq(100);

More info about the callStatic is available here

  • That is amazing it works! Thank you so much. Which solution would you say is better practice?
    – Btadford
    Feb 17, 2022 at 20:07
  • The first one, with the view addition
    – Andrej
    Feb 17, 2022 at 20:12

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