Cannot call methods in a script with an invalid name from other methods in that same script

[awittha]

Expected Behavior

Given a script with an invalid JVM name, like some-script.groovy, and contents with multiple methods:

def one() {}

def two() {
  one()
}

return this

I would expect to be able to call method two() during a test, like this:

setup:
  def script = loadPipelineScriptForTest( "some-script.groovy ")
when:
  script.two()
then:
  // some expectation

Actual Behavior

The fact that some-script.groovy is compiled to a class file whose name is not valid to a JVM is a problem. Branch https://github.com/ExpediaGroup/jenkins-spock/tree/invalid-name-internal adds a unit test; the output is

[ERROR] can run methods in helper scripts whose names create invalid JVM class names from other methods in those scripts(com.homeaway.devtools.jenkins.testing.scripts.InvalidClassNameSpec)  Time elapsed: 0.043 s  <<< ERROR!
java.lang.ClassFormatError: Illegal class name "some-helper-script$internal_method" in class file some-helper-script$internal_method
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
	at some-helper-script.composed_method(some-helper-script.groovy:27)
	at com.homeaway.devtools.jenkins.testing.InvalidlyNamedScriptWrapper.invokeMethod(InvalidlyNamedScriptWrapper.groovy:68)
	at com.homeaway.devtools.jenkins.testing.scripts.InvalidClassNameSpec.can run methods in helper scripts whose names create invalid JVM class names from other methods in those scripts(InvalidClassNameSpec.groovy:96)

Steps to Reproduce

See the unit tests added in branch https://github.com/ExpediaGroup/jenkins-spock/tree/invalid-name-internal

Additional Information

This may just mean that the "invalid class name" handling needs to be improved.

This may be symptomatic of the script-loading mechanism being used incorrectly and may warrant looking into alternate implementations for this snippet:

jenkins-spock/src/main/groovy/com/homeaway/devtools/jenkins/testing/JenkinsPipelineSpecification.groovy

Lines 886 to 911 in c864e4e

	protected Script loadPipelineScriptForTest(String _path) {
	String[] path_parts = _path.split( "/" )
	String filename = path_parts[path_parts.length-1]
	String resource_path = "/"
	if( path_parts.length >= 2 ) {
	resource_path = String.join( "/", path_parts[0..path_parts.length-2] )
	resource_path = "/${resource_path}/"
	}
	GroovyScriptEngine script_engine = new GroovyScriptEngine(generateScriptClasspath(resource_path))
	Class<Script> script_class = script_engine.loadScriptByName( "${filename}" )
	Script script = script_class.newInstance()
	addPipelineMocksToObjects( script )
	if( SourceVersion.isName( script_class.getSimpleName() ) ) {
	return script
	} else {
	return new InvalidlyNamedScriptWrapper( script )
	}
	}

We should investigate and if it can be solved with the Wrapper, make sure that N & N+1 layers of nesting are solved, too.