An empty interface to be used with the
Expectations.result field or the
Invocations#with(Delegate) method, allowing test code
to define varying invocation results or argument matching rules, respectively.
When combined with the
result field, a test will typically assign it with an anonymous class object
implementing this interface and containing a
delegate method:
new Expectations() {{
mock.doSomething(anyInt, anyString);
result = new Delegate() {
String delegate(int i, String s) {
return i > 0 ? s : "";
}
};
}};
tested.exerciseCodeUnderTest();
The delegate class (either named or anonymous) must contain exactly one non-
private instance method to
be executed when the mocked method or mocked constructor is invoked; it can contain any number of
private
or
static methods, though.
The name of the delegate method can be anything.
Its parameters, however, should be the same as the parameters of the corresponding mocked method/constructor, or at
least be compatible with them.
Optionally, the delegate method can have an extra parameter of type
Invocation, provided it appears as the
first one.
The delegate method is also allowed to have
no parameters (without counting the optional
Invocation
parameter).
When used with the
result field, the result of a delegate method execution can be any return value compatible
with the recorded method's return type, or a thrown error/exception.
When used with the
with(Delegate) method, the delegate method must return a
boolean, being
true for a successfully matched argument or
false otherwise.
Finally, note that a
static method in the mocked type can have a delegate as well.
The same is true for
private,
final, and
native methods.
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