Grails 6.2.2: ClassCastException for inheritance in Commands

[agre1981]

Expected Behavior

Grails throws exception ClassCastException when we have 2 endpoints with inherited commands. It worked fine on 6.1.2.

Looks like this is a critical issue.

class UrlMappings {
        "/my/$patientId/procedure"(controller: "my", action: "createLedgerProcedure", method: "POST")
        "/my/$patientId/procedure/insuranceEstimates"(controller: "my", action: "getInsuranceEstimates", method: "POST")
}

class MyBaseCommand implements Validateable {

    int testId
}

class MyCommand extends MyBaseCommand {

    int myId
}

class MyController {
    def getInsuranceEstimates(MyCommand command, long patientId) {
        log.info('test2 method')
        render([response: "test2 method"] as JSON)
    }

    def createLedgerProcedure(MyBaseCommand command, long patientId) {
        log.info('test1 method')
        render([response: "test1 method"] as JSON)
    }

}

Actual Behaviour

Exception:

2024-12-26 18:13:10.639 ERROR --- [nio-8080-exec-2] StackTrace                               : Full Stack Trace:

java.lang.reflect.InvocationTargetException: null
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at org.grails.core.DefaultGrailsControllerClass$ReflectionInvoker.invoke(DefaultGrailsControllerClass.java:211)
	at org.grails.core.DefaultGrailsControllerClass.invoke(DefaultGrailsControllerClass.java:188)
	at org.grails.web.mapping.mvc.UrlMappingsInfoHandlerAdapter.handle(UrlMappingsInfoHandlerAdapter.groovy:90)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1072)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:965)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
	at org.grails.web.servlet.mvc.GrailsWebRequestFilter.doFilterInternal(GrailsWebRequestFilter.java:77)
	at org.grails.web.filters.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:67)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.ClassCastException: class com.example.MyBaseCommand cannot be cast to class com.example.MyCommand (com.example.MyBaseCommand and com.example.MyCommand are in unnamed module of loader org.springframework.boot.devtools.restart.classloader.RestartClassLoader @8f4db8)
	... 13 common frames omitted

2024-12-26 18:13:10.690 ERROR --- [nio-8080-exec-2] o.g.web.errors.GrailsExceptionResolver   : ClassCastException occurred when processing request: [POST] /my/123/procedure
class com.example.MyBaseCommand cannot be cast to class com.example.MyCommand (com.example.MyBaseCommand and com.example.MyCommand are in unnamed module of loader org.springframework.boot.devtools.restart.classloader.RestartClassLoader @8f4db8). Stacktrace follows:

java.lang.reflect.InvocationTargetException: null
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at org.grails.core.DefaultGrailsControllerClass$ReflectionInvoker.invoke(DefaultGrailsControllerClass.java:211)
	at org.grails.core.DefaultGrailsControllerClass.invoke(DefaultGrailsControllerClass.java:188)
	at org.grails.web.mapping.mvc.UrlMappingsInfoHandlerAdapter.handle(UrlMappingsInfoHandlerAdapter.groovy:90)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1072)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:965)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
	at org.grails.web.servlet.mvc.GrailsWebRequestFilter.doFilterInternal(GrailsWebRequestFilter.java:77)
	at org.grails.web.filters.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:67)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.ClassCastException: class com.example.MyBaseCommand cannot be cast to class com.example.MyCommand (com.example.MyBaseCommand and com.example.MyCommand are in unnamed module of loader org.springframework.boot.devtools.restart.classloader.RestartClassLoader @8f4db8)
	... 13 common frames omitted

Steps To Reproduce

Reproduces on Grails 6.2.2. It worked fine on 6.1.2.

grails_6_2_2.zip

An example of the application has been attached:

• run the attached application: ./gradlew bootRun
• Send the request:

curl --location --request POST 'http://localhost:8080/my/123/procedure' \
--header 'Content-Type: application/json' \
--data '{
    "testId": 321
}'

Environment Information

• Windows 10
• Java:

openjdk version "11.0.22" 2024-01-16
OpenJDK Runtime Environment Temurin-11.0.22+7 (build 11.0.22+7)
OpenJDK 64-Bit Server VM Temurin-11.0.22+7 (build 11.0.22+7, mixed mode)

Example Application

No response

Version

6.2.2

[agre1981]

Maybe relates to #13486

[agre1981]

Class file:
MyController.zip

[jdaugherty]

I added 2 tests for this issue under my 6.2.x branch & 7.x:

@Issue('https://github.com/grails/grails-core/issues/13945')
void "calling actions involving inherited command objects - parent command"() {
    given:
    params.name = 'Douglas'

    when:
    def model = controller.methodTakingParent()
    def commandObject = model.commandObject

    then:
    commandObject.name == 'Douglas'
}

@Issue('https://github.com/grails/grails-core/issues/13945')
void "calling actions involving inherited command objects - child command"() {
    given:
    params.name = 'Douglas'
    params.anotherName = 'Fir'

    when:
    def model = controller.methodTakingChild()
    def commandObject = model.commandObject

    then:
    commandObject.name == 'Douglas'
    commandObject.anotherName == 'Fir'
}

And the associated Commands:

class ParentCommandObject {
    String name
}

class ChildCommandObject extends ParentCommandObject {
    String anotherName
}

And the associated action:

def methodTakingParent(ParentCommandObject co) {
    [commandObject: co]
}

def methodTakingChild(ChildCommandObject co) {
    [commandObject: co]
}

Neither of these tests are failing in either branch. I'm still researching.

[agre1981]

@jdaugherty could you push the tests? I'll try to help with reproducing of the issue

[jdaugherty]

I figured out the cause of this. I'll push the tests here shortly. The name of the method & the arguments to that method seem to matter. The actual cast exception is happening on the validate() call:

[jdaugherty]

Commit 268e386 reproduces this issue. I've gone ahead and marked the test with @PendingFeature to not fail the test run until this is fixed.

[agre1981]

The test doesn't fail without Validatable for me

[jdaugherty]

There seems to be some randomness. The test run passed unexpectedly so this leads me to believe there's an ordering issue involved.

[jdaugherty]

I changed the code that calls validate in the action transformer, and this now is generated:

Which makes the test pass.

[agre1981]

For me, it constantly fails with Validateable and constantly passes without Validateable. My command:

./gradlew :grails-test-suite-web:clean :grails-test-suite-web:singleTest --tests "org.grails.web.commandobjects.CommandObjectsSpec"