Unit Tests

You can unit test abstracted logic implemented by smart contract functions like regular JavaScript functions with any testing library of your liking. A simple example would look as follows:

Contract

@NearBindgen({})
export class Contract {
  ...
  doSomething(): string {
    return callSomeFunction();
  }
}

Unit Test File

describe('Contract', () => {
  it('callSomeFunction should work', () => {
    ...
    results = callSomeFunction();
    // then assert results are what you expect
    ....
  });
});

As for testing the smart contract functions themselves, we recommend using integration tests instead as they fully replicate the environment on which that logic will run.