[GROOVY-9932] MockFor/StubFor makes mocked internal method return null

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.0, 3.0.7
• Fix Version/s: 3.0.8, 4.0.0-alpha-3
• Assignee: Daniel Sun
• Reporter: Ryan Tandy
• Created: 08/Feb/21 22:26
• Updated: 25/Apr/21 03:34
• Resolved: 16/Feb/21 18:00

Description

import groovy.mock.interceptor.MockFor

class Helper {
    String string

    Helper() {
        string = internalMethod()
    }

    private String internalMethod() {
        return helperMethod()
    }

    String helperMethod() {
        return 'not intercepted'
    }
}

MockFor mock = new MockFor(Helper)
mock.demand.helperMethod { -> 'intercepted' }
mock.ignore('getString')

mock.use {
    def helper = new Helper()
    assert helper.string == 'intercepted'
}

method() is a public method, thus I expect it to respect mocking, even for internal calls. Let me know if this expectation is wrong.

With Groovy 2.4.21, the test works as expected. With Groovy 3.0.7, it fails:

Assertion failed: 

assert helper.string == 'stub'
       |      |      |
       |      null   false
       Helper@5c00384f

	at test$_run_closure2.doCall(test.groovy:17)
	at test$_run_closure2.doCall(test.groovy)
	at test.run(test.groovy:15)

Instead of either the original or mocked return value, we got null instead.

It looks like it works for call(), but not for callCurrent(). I think the issue is that MockProxyMetaClass overrides one signature of invokeMethod(), but not the one used by callCurrent(). Might 34ad466ba6a be a relevant change?