I've learned from this question that it is not (always) possible to compute the gas-costs of an arbitrary solidity contract
a.sol because the amount of computation that it takes may depend on the input it receives from the other smart contracts that it interacts with.
However, in for example the HardHat or Waffle test framework, one can feed your smart contract
a.sol, all of its other smart contracts. Yet I did not yet find a clear indication of the gas costs of that contract. (After the tests were completed, before it was deployed to main-net).
So, assuming one has enough coverage in the tests (contracts), one could get an accurate enough range of the gas costs as a function of various input (test) contracts.
Are there applications/code solutions (in HardHat) that instantly give the gas costs of a contract based on specific input contracts? (Ideally, a minimal working example (MWE) of parameterised plot based on certain input variables could be presented).