CPS transformation should honor the return type signature

[kohsuke]

CPS transformation ignores the declared return type of function, and always treat as if it is typed as Object.

This creates a behaviour difference between normal Groovy code vs CPS-transformed code.

int foo() { return "abc" }
foo();  // compiles fine but at runtime throws ClassCastException

void bar() { 42; }
x=bar(); // runs fine but assigns null

This should be relatively easy by having Continuation check the type of the value (or substitute it by null in case of void methods)

[dwnusbaum]

I noticed this while working on SECURITY-2824. I added a new test that demonstrates the issue:

groovy-cps/lib/src/test/java/com/cloudbees/groovy/cps/CpsTransformerTest.java

Line 1036 in bd35d05

@Test public void methodReturnValuesShouldBeCastToDeclaredReturnType() throws Throwable {

I am closing this issue. If anyone comes across this and cares about the behavior, feel free to file a new issue on https://issues.jenkins.io/ with the component set to workflow-cps-plugin, but note that unless you work on it yourself it is very unlikely to ever be fixed.