error at test contract

[muhammet72]

I tried to write a test for array remove by shifting but I got errors could you help me with it

Contract

// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.17;

// array remove by shift
contract ArrayShift {
  // [1, 2, 3] -- remove(1) --> [1, 3, 3] --> [1, 3]
  // [1, 2, 3, 4, 5, 6] -- remove(2) --> [1, 2, 4, 5, 6, 6] --> [1, 2, 4, 5, 6]
  // [1, 2, 3, 4, 5, 6] -- remove(0) --> [2, 3, 4, 5, 6, 6] --> [2, 3, 4, 5, 6]
  // [1] -- remove(0) --> [1] --> []}

  uint[] public arr;

  function remove(uint _index) public {
    require(_index < arr.length, "index out of bound");

    // steps of remove function
    // [1,2,3,4,5] -- remove(1) --> ( step 1 loop --> [1,3,3,4,5],  --> [1,3,4,4,5],  --> [1,3,4,5,5], step 2 --> pop()) --> [1,3,4,5]

    for (uint i = _index; i < arr.length - 1; i++) {
      arr[i] = arr[i + 1];
    }
    arr.pop();
  }

  function test() external {
    arr = [1, 2, 3, 4, 5];
    remove(2);

    assert(arr[0] == 1);
    assert(arr[1] == 2);
    assert(arr[2] == 4);
    assert(arr[3] == 5);
    assert(arr.length == 4);

    arr = [1];
    remove(0);
    assert(arr.length == 0);
  }
}

Test

const { network, getNamedAccounts, deployments, ethers } = require("hardhat")
const { developmentChains, networkConfig } = require("../helper-hardhat-config")
const { assert, expect } = require("chai")

describe("ArrayShift", async () => {
  let arrayShift
  let accounts = []
  before(async () => {
    deployer = (await getNamedAccounts()).deployer
    await deployments.fixture(["all"])
    arrayShift = await ethers.getContract("ArrayShift", deployer)
  })

  describe("remove", async () => {
    it("revert if index bigger than array.length", async () => {
      await expect(arrayShift.remove(10)).to.be.revertedWith("index out of bound")
    })
  })

  describe("test", async () => {
    it("test1", async () => {
      await arrayShift.test()

      const arr = await arrayShift.arr()
      expect(arr[0]).to.equal(1)
      expect(arr[1]).to.equal(2)
      expect(arr[2]).to.equal(4)
      expect(arr[3]).to.equal(5)
      expect(arr.length).to.equal(4)
    })
    it("test2", async () => {
      await arrayShift.test()
      const arr = await arrayShift.arr()
      expect(arr.length).to.equal(0)
    })
  })
})

error

Error: missing argument: passed to contract (count=0, expectedCount=1, code=MISSING_ARGUMENT, `version=contracts/5.7.0)

[muhammet72]

error

1) ArrayShift
       test
         test1:
     Error: missing argument: passed to contract (count=0, expectedCount=1, code=MISSING_ARGUMENT, version=contracts/5.7.0)
      at Logger.makeError (node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
      at Logger.throwError (node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
      at Logger.checkArgumentCount (node_modules/@ethersproject/logger/src.ts/index.ts:340:18)
      at /home/code/dapps-hardhat/node_modules/@ethersproject/contracts/src.ts/index.ts:187:12
      at step (node_modules/@ethersproject/contracts/lib/index.js:48:23)
      at Object.next (node_modules/@ethersproject/contracts/lib/index.js:29:53)
      at /home/code/dapps-hardhat/node_modules/@ethersproject/contracts/lib/index.js:23:71
      at new Promise (<anonymous>)
      at __awaiter (node_modules/@ethersproject/contracts/lib/index.js:19:12)
      at populateTransaction (node_modules/@ethersproject/contracts/lib/index.js:152:12)

  2) ArrayShift
       test
         test2:
     Error: missing argument: passed to contract (count=0, expectedCount=1, code=MISSING_ARGUMENT, version=contracts/5.7.0)
      at Logger.makeError (node_modules/@ethersproject/logger/src.ts/index.ts:269:28)
      at Logger.throwError (node_modules/@ethersproject/logger/src.ts/index.ts:281:20)
      at Logger.checkArgumentCount (node_modules/@ethersproject/logger/src.ts/index.ts:340:18)
      at /home/code/dapps-hardhat/node_modules/@ethersproject/contracts/src.ts/index.ts:187:12
      at step (node_modules/@ethersproject/contracts/lib/index.js:48:23)
      at Object.next (node_modules/@ethersproject/contracts/lib/index.js:29:53)
      at /home/code/dapps-hardhat/node_modules/@ethersproject/contracts/lib/index.js:23:71
      at new Promise (<anonymous>)
      at __awaiter (node_modules/@ethersproject/contracts/lib/index.js:19:12)
      at populateTransaction (node_modules/@ethersproject/contracts/lib/index.js:152:12)

[Nlferu]

Hello @muhammet72

I have tip for you, if you are removing items from array in for loop your array is changing and that is why you are keep getting errors, you should keep track of current array. Also very good practice to work on removals is to make reverse loops, so no i++ but use i-- instead :)

[muhammet72]

Hello @Neftyr

I couldn't understand, how to keep track of the current array. can you show me an example?
also, I have the same error with Array remove by replacing the last element.

// SPDX-License-Identifier: SEE LICENSE IN LICENSE
pragma solidity 0.8.17;

contract ArrayReplaceLast {
  uint[] public arr;

  // Deleting an element creates a gap in the array.
  // One trick to keep the array compact is to
  // move the last element into the place to delete.
  function remove(uint _index) public {
    // Move the last element into the place to delete
    arr[_index] = arr[arr.length - 1];
    // Remove the last element
    arr.pop();
  }

  function test() external {
    arr = [1, 2, 3, 4];

    remove(1);
    // [1, 4, 3]
    assert(arr.length == 3);
    assert(arr[0] == 1);
    assert(arr[1] == 4);
    assert(arr[2] == 3);

    remove(2);
    // [1, 4]
    assert(arr.length == 2);
    assert(arr[0] == 1);
    assert(arr[1] == 4);
  }
}

can you explain in more detail?

[Nlferu]

Hi @muhammet72

Some tips and examples for you below:

for (uint borrower = borrowersLength[tokenId] - 1; borrower >= 0; borrower--) {
                    if (cert.tokenIdToBorrowToEnd[cert.tokenIdToBorrowers[borrower]] < block.timestamp) {
                        licenseStatusUpdater(tokenId, cert.tokenIdToBorrowers[borrower]);
                    }
                }

LicenseStatusUpdater function:

 // Removing borrower from array of borrowers for given tokenId
        for (uint i = 0; i < cert.tokenIdToBorrowers.length; i++) {
            if (cert.tokenIdToBorrowers[i] == borrower) {
                emit LicenseRemoved(borrower, tokenId);
                // Swapping borrower to be removed with last borrower in array
                cert.tokenIdToBorrowers[i] = cert.tokenIdToBorrowers[cert.tokenIdToBorrowers.length - 1];
                cert.tokenIdToBorrowers.pop();
            }
        }

In this example we are searching for element in array, which we want to remove (meets certain conditions), once we find it we simply swaping it with last element in array and do .pop() to remove it. This is very simple trick and if you noticed I'm also using reversal loop with i-- in upper function. This example should be enough for you to solve your issue :)