public static final java.lang.String TARGET_VIEW_RESOLVER_BEAN_NAME

The primary GSP view resolver bean name in Grails. The historical name jspViewResolver is kept for compatibility with the plugin's GroovyPagesPostProcessor, which registers the GSP resolver under that name when it isn't already present (see org.grails.plugins.web.GroovyPagesPostProcessor). The modern GspAutoConfiguration.gspViewResolver() bean is aliased to this name too when it fires.

public GrailsSiteMeshViewResolverBeanPostProcessor()

@java.lang.Override
public java.lang.Object postProcessAfterInitialization(java.lang.Object bean, java.lang.String beanName)

Contexts can include this post-processor (via Sitemesh3AutoConfiguration) without the SiteMesh plugin beans being registered — the unit-test context built by grails-testing-support registers all Grails auto-configurations but never runs the plugin's doWithSpring. Decoration is impossible without those beans, so leave the view resolver unwrapped instead of failing the context.

Resolvers implementing ApplicationListener are also left unwrapped. When the legacy grails-layout module is on the classpath its post-processor installs the SiteMesh 2 GrailsLayoutViewResolver (an ApplicationListener) as jspViewResolver; that resolver already decorates, and wrapping it would additionally break Spring's event listener retrieval, which expects the instance to match the definition's listener type.