About solidity structs

i am writting unit testing with typescript for my contracts ,
and there is one struct in it
that i want to make use of it in my test

i've tried many ways , but all of them saying that those elements inside struct are undefined

an example of test struct :

struct TxCommon {
    bool A;
    uint256 B;
    uint256 C;

How do you init them ?

Are you using typechain? The struct should be generated along the rest of the typescript interface. Some times, depending on whether you use this struct as input parameter, or as return from a function, it can have a slightly different name, but it should be there