preserve generic wildcard parameter

Author: hauner

src/main/kotlin/io/openapiprocessor/core/processor/mapping/v2/parser/ToExtractor.kt

@@ -35,9 +35,12 @@ class ToExtractor: ToBaseListener() {
         ctx.typeArguments ()
             ?.typeArgumentList ()
             ?.typeArgument ()
-            ?.filter { it.type() != null }
             ?.forEach {
-                typeArguments.add(it.type ().text)
+                if (it.text == "?") {
+                    typeArguments.add("?")
+                } else if (it.type() != null) {
+                    typeArguments.add(it.type ().text)
+                }
             }
     }
 

src/test/groovy/io/openapiprocessor/core/processor/mapping/v2/parser/ToParserSpec.groovy

@@ -35,7 +35,7 @@ class ToParserSpec extends Specification {
         'io.openapiprocessor.Foo'         | 'io.openapiprocessor.Foo' | []
         '  io . openapiprocessor .  Foo ' | 'io.openapiprocessor.Foo' | []
         'A<>'                             | 'A'                       | []
-        'A<?>'                            | 'A'                       | []
+        'A<?>'                            | 'A'                       | ['?']
         'A<b.B, c.C>'                     | 'A'                       | ['b.B', 'c.C']
         'A<B, C>'                         | 'A'                       | ['B', 'C']
     }