[JENKINS-34070] Better handle mismatched types

[jglick]

JENKINS-34070

Prior to fix, the test would fail with a misleading error:

org.kohsuke.stapler.NoStaplerConstructorException: There's no @DataBoundConstructor on any constructor of class org.jenkinsci.plugins.gitclient.MergeCommand$Strategy
    at org.kohsuke.stapler.ClassDescriptor.loadConstructorParamNames(ClassDescriptor.java:177)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.<init>(DescribableModel.java:114)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.of(DescribableModel.java:100)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate__(DescribableModel.java:477)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate_(DescribableModel.java:474)
    at org.jenkinsci.plugins.structs.describable.DescribableParameter.uncoerce(DescribableParameter.java:174)
    at org.jenkinsci.plugins.structs.describable.DescribableParameter.inspect(DescribableParameter.java:122)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate(DescribableModel.java:435)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate__(DescribableModel.java:477)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate_(DescribableModel.java:474)
    at org.jenkinsci.plugins.structs.describable.DescribableModelTest.roundTrip(DescribableModelTest.java:636)
    at org.jenkinsci.plugins.structs.describable.DescribableModelTest.userMergeOptions(DescribableModelTest.java:600)

Now it will still fail, but only with incorrect output:

expected:<{fastForwardMode=FF_ONLY, mergeRemote=x, mergeStrategy=OCTOPUS, mergeTarget=y}> but was:<{fastForwardMode=FF_ONLY, mergeRemote=x, mergeStrategy=default, mergeTarget=y}>

after printing a warning that more accurately represents what is wrong in the signature of UserMergeOptions:

WARNING: Cannot create control version of class hudson.plugins.git.UserMergeOptions using {fastForwardMode=FF_ONLY, mergeRemote=x, mergeStrategy=default, mergeTarget=y}
java.lang.ClassCastException: hudson.plugins.git.UserMergeOptions.mergeStrategy expects class java.lang.String but received class org.jenkinsci.plugins.gitclient.MergeCommand$Strategy
    at org.jenkinsci.plugins.structs.describable.DescribableModel.coerce(DescribableModel.java:326)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.buildArguments(DescribableModel.java:257)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.instantiate(DescribableModel.java:201)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate(DescribableModel.java:449)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate__(DescribableModel.java:477)
    at org.jenkinsci.plugins.structs.describable.DescribableModel.uninstantiate_(DescribableModel.java:474)
    at org.jenkinsci.plugins.structs.describable.DescribableModelTest.roundTrip(DescribableModelTest.java:636)
    at org.jenkinsci.plugins.structs.describable.DescribableModelTest.userMergeOptions(DescribableModelTest.java:600)

@reviewbybees

[ghost]

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[jenkinsadmin]

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[andresrc]

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