List<PathSegment> exception on RESTEasy Reactive

[tedwon]

Describe the bug

As I asked in Zulip, I wanted to use List<PathSegment> with RESTEasy Reactive extension to use @PathParam and Regular Expressions. i.e. @path("{keyword:.*}")
https://docs.jboss.org/resteasy/docs/4.6.0.Final/userguide/html_single/index.html#_PathParam_and_PathSegment

But I'm getting exceptions as below:
https://github.com/tedwon/quarkus-resteasy-reactive-with-pathsegment/blob/master/README.adoc

It is working properly with @PathParam("id") PathSegment id:
https://github.com/tedwon/quarkus-resteasy-reactive-with-pathsegment/blob/master/src/main/java/org/acme/getting/started/ReactiveGreetingResource.java#L51-L55

However, getting errors java.lang.RuntimeException: Failed to find converter for javax.ws.rs.core.PathSegment with @PathParam("keyword") List<PathSegment> keywords while startup Quarkus.
https://github.com/tedwon/quarkus-resteasy-reactive-with-pathsegment/blob/master/src/main/java/org/acme/getting/started/ReactiveGreetingResource.java#L57-L61

Note that it is working properly for the same code with List on my other Quarkus app with quarkus-resteasy extension.

Expected behavior

No exception for the usage of List with quarkus-resteasy extension

Actual behavior

2021-05-02 02:16:02,416 ERROR [io.qua.dep.dev.IsolatedDevModeMain] (main) Failed to start quarkus: java.lang.RuntimeException: io.quarkus.builder.BuildException: Build failure: Build failed due to errors
	[error]: Build step io.quarkus.resteasy.reactive.server.deployment.ResteasyReactiveProcessor#setupEndpoints threw an exception: java.lang.RuntimeException: java.lang.RuntimeException: Failed to process method org.acme.getting.started.ReactiveGreetingResource#java.lang.String searchByKeywords(java.util.List<javax.ws.rs.core.PathSegment> keywords)
	at org.jboss.resteasy.reactive.common.processor.EndpointIndexer.createEndpoints(EndpointIndexer.java:238)
	at io.quarkus.resteasy.reactive.server.deployment.ResteasyReactiveProcessor.setupEndpoints(ResteasyReactiveProcessor.java:402)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at io.quarkus.deployment.ExtensionLoader$2.execute(ExtensionLoader.java:920)
	at io.quarkus.builder.BuildContext.run(BuildContext.java:277)
	at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2415)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1452)
	at java.base/java.lang.Thread.run(Thread.java:834)
	at org.jboss.threads.JBossThread.run(JBossThread.java:501)
Caused by: java.lang.RuntimeException: Failed to process method org.acme.getting.started.ReactiveGreetingResource#java.lang.String searchByKeywords(java.util.List<javax.ws.rs.core.PathSegment> keywords)
	at org.jboss.resteasy.reactive.common.processor.EndpointIndexer.createResourceMethod(EndpointIndexer.java:524)
	at org.jboss.resteasy.reactive.common.processor.EndpointIndexer.createEndpoints(EndpointIndexer.java:285)
	at org.jboss.resteasy.reactive.common.processor.EndpointIndexer.createEndpoints(EndpointIndexer.java:209)
	... 11 more
Caused by: java.lang.RuntimeException: Failed to find converter for javax.ws.rs.core.PathSegment
	at io.quarkus.resteasy.reactive.server.deployment.QuarkusServerEndpointIndexer.extractConverter(QuarkusServerEndpointIndexer.java:198)
	at org.jboss.resteasy.reactive.server.processor.ServerEndpointIndexer.handleListParam(ServerEndpointIndexer.java:277)
	at org.jboss.resteasy.reactive.server.processor.ServerEndpointIndexer.handleListParam(ServerEndpointIndexer.java:57)
	at org.jboss.resteasy.reactive.common.processor.EndpointIndexer.extractParameterInfo(EndpointIndexer.java:909)
	at org.jboss.resteasy.reactive.common.processor.EndpointIndexer.createResourceMethod(EndpointIndexer.java:407)
	... 13 more

To Reproduce

Please run this reproducer project:
https://github.com/tedwon/quarkus-resteasy-reactive-with-pathsegment

./mvnw quarkus:dev

Quarkus version or git rev

QUARKUS 1.13.3

[quarkus-bot]

/cc @FroMage, @geoand, @stuartwdouglas

[geoand]

Can you give an example of how you expect this to work?
Furthermore, does it work with RESTEasy Classic?

[FroMage]

I thought this would be confusing at first too, but the spec gives this example: https://quarkus.io/specs/jaxrs/2.1/index.html#uritemplates

With @Path("widgets/{path:.+}") given the request path widgets/small/a the value of path would be small/a.

From which we can guess that a List<PathSegment> of those would have two entries: one for small and one for a.

Either the TCK doesn't test for this, or we disabled that test. Not sure how easy it would be to support this, or how useful.

I wonder if it would make as much sense to support List<String> and other collections for @PathParam if there's a regex in the URI template.

[gastaldi]

I'm facing the same error while trying to convert registry.quarkus.io to RestEasy Reactive.
This is the endpoint:

    @GET
    @Path("{path:.+}")
    public Response handleArtifactRequest(
            @PathParam("path") List<PathSegment> pathSegments,
            @Context UriInfo uriInfo) {
			...
    }