Testing on Hardhat Simple Storage

[RevanthGundala]

I was trying to write an additional test to see if the contract could add a new person to the array and if the contract's mapping worked as intended:

 it("Should correctly add a new person with a name and fav num", async function () {
        const tx = await simpleStorage.addPerson("Bob", "9");
        await tx.wait(1);

        const favNumber = 9;

        assert.equal(
            simpleStorage.nameToFavoriteNumber(simpleStorage.people[0].name),
            favNumber
        );
    });

I am getting this error :

TypeError: Cannot read properties of undefined (reading 'name')
      at Context.<anonymous> (test/test-deploy.js:38:72)
      at processTicksAndRejections (node:internal/process/task_queues:96:5)
      at runNextTicks (node:internal/process/task_queues:65:3)
      at listOnTimeout (node:internal/timers:528:9)
      at processTimers (node:internal/timers:502:7)

Does anyone know how I would correctly format the assert statement to test this?

[PatrickAlphaC]

Good question, remember though, in javascript, every smart contract function call is an API call to the smart contract - not the data structure itself.

simpleStorage.people[0].name

the syntax you’re using here is solidity, but you’re writing in JavaScript!

I’m assuming people is your array, so you’d want to do:

simpleStorage.people(0)

and get the name from that object! Could you try that?

Then try:

const person = await simpleStorage.people(0)
const name  = person.name
console.log(name)

And you might find your answer :)

[RevanthGundala]

Ok, I tried to do a couple of log statements and here's what I found.

This statement:

console.log(await simpleStorage.people(0));

returned

[
  BigNumber { value: "9" },
  'Bob',
  favoriteNumber: BigNumber { value: "9" },
  name: 'Bob'
]

and this statement:

console.log(await simpleStorage.people(0).name);

returned

undefined

Previously, I didn't use await to access the array so it was just printing out a pending promise, but after I added it in I could access the array elements. However, I am a bit confused why I am getting an undefined statement when I try to access the name (I think this is the format you were asking me to use to get the name).

[TilakMaddy]

do it like this

console.log((await simpleStorage.people(0)).name);

[TilakMaddy]

simpleStorage.people(0) returns a promise that resolves to the object which you console logged in the above reply. However simpleSrorage.people(0).name will be undefined because a javascript promise does not have any method / attribute named 'name'
You would wait for it to resolve first, then call the 'name' attribute on the object

[TilakMaddy]

Another way to do that would be

const person = await simpleStorage.people(0)
const name  = person.name
console.log(name)

OR

const  { name } = await simpleStorage.people(0)
console.log(name)

[RevanthGundala]

Got it, thanks!