Flutter: Test that a specific exception is thrown

Question

in short, throwsA(anything) does not suffice for me while unit testing in dart. How to I test for a specific error message or type?

Her

Answer 1

In case anyone wants to test with an async function like I had to do all you need to do is add async keyword in the expect, bearing in mind that the lookupOrderDetails is an async function:

expect(() **async** => **await** operations.lookupOrderDetails(), throwsA(const TypeMatcher()));

expect(() **async** => **await** operations.lookupOrderDetails(), isInstanceOf()));

It still uses Gunter's answer which is very good!