You can just assign the mock to the static method
import A from '../src/a'
import B from '../src/b'
jest.mock('../src/a')
describe('Wallet', () => {
it('should work', () => {
const mockStaticF = jest.fn().mockReturnValue('worked')
A.staticF = mockStaticF
const b = new B()
const result = b.gCallsStaticF()
expect(result).toEqual('worked')
})
})