I want to use the totalSupply function within an extension contract, but the function is not declared within the contract and is added in from a different contract extension. Both extensions are imports into the main contract file. How can utilize a function defined within "contract B2", in "contract B1" when the only relationship between them is that they are both inherited extensions in contract A?
Total noob to programming and solidity here, please bare with me. Thanks in advance.
So if I have understood you right, there are some options. I would prefer to use a common interface, and as contract B1 doesn't implement the interface, you should mark it as abstract:
interface IContractB { function someAbstract() external view returns (uint256); } abstract contract B1 is IContractB { function foo () view external returns (uint256) { return this.someAbstract(); } } contract B2 is IContractB { function someAbstract() override external view returns (uint256) { return 5; } } contract A is B1, B2 { } Now, when you deploy A and call the method foo, it will run the method foo from B1, which calls method someAbstract, which is implemented in B2. The return will be 5.
There is even a way without the common interface, but it would be the antipattern and additionally, it requires the shallow methods in contract A
abstract contract B1 { function foo () view external returns (uint256) { return this.someAbstract(); } function someAbstract() public view virtual returns (uint256); } contract B2 { function someAbstract() public view virtual returns (uint256) { return 5; } } contract A is B1, B2 { function someAbstract() override(B1, B2) public view virtual returns (uint256) { return super.someAbstract(); } } 