add support for generics in CRD generation

crd-generator/api/src/main/java/io/fabric8/crd/generator/AbstractJsonSchema.java

@@ -193,7 +193,7 @@ public boolean isPreserveUnknownFields() {
    */
   protected T internalFrom(TypeDef definition, String... ignore) {
     List<InternalSchemaSwap> schemaSwaps = new ArrayList<>();
-    T ret = internalFromImpl(definition, new HashSet<>(), schemaSwaps, ignore);
+    T ret = internalFromImpl(definition, new HashSet<>(), schemaSwaps, new ParameterMap(new HashMap<>()), ignore);
     validateRemainingSchemaSwaps("unmatched class", schemaSwaps);
     return ret;
   }
@@ -277,7 +277,7 @@ private void validateRemainingSchemaSwaps(String error, List<InternalSchemaSwap>
     }
   }
 
-  private T internalFromImpl(TypeDef definition, Set<String> visited, List<InternalSchemaSwap> schemaSwaps, String... ignore) {
+  private T internalFromImpl(TypeDef definition, Set<String> visited, List<InternalSchemaSwap> schemaSwaps, ParameterMap parameterMap, String... ignore) {
     final B builder = newBuilder();
     Set<String> ignores =
       ignore.length > 0 ? new LinkedHashSet<>(Arrays.asList(ignore)) : Collections
@@ -312,7 +312,7 @@ private T internalFromImpl(TypeDef definition, Set<String> visited, List<Interna
         continue;
       }
 
-      final PropertyFacade facade = new PropertyFacade(property, accessors, currentSchemaSwaps);
+      final PropertyFacade facade = new PropertyFacade(property, accessors, currentSchemaSwaps, parameterMap);
       final Property possiblyRenamedProperty = facade.process();
       final Set<InternalSchemaSwap> matchedSchemaSwaps = facade.getMatchedSchemaSwaps();
       currentSchemaSwaps.removeAll(matchedSchemaSwaps);
@@ -324,7 +324,7 @@ private T internalFromImpl(TypeDef definition, Set<String> visited, List<Interna
       } else if (facade.ignored) {
         continue;
       }
-      final T schema = internalFromImpl(name, possiblyRenamedProperty.getTypeRef(), visited, schemaSwaps);
+      final T schema = internalFromImpl(name, possiblyRenamedProperty.getTypeRef(), visited, schemaSwaps, parameterMap);
       if (facade.preserveUnknownFields) {
         preserveUnknownFields = true;
       }
@@ -363,6 +363,45 @@ private Map<String, Method> indexPotentialAccessors(TypeDef definition) {
     return accessors;
   }
 
+  private static class ParameterMap {
+    final Map<String, TypeRef> mappings;
+
+    ParameterMap(Map<String, TypeRef> mappings) {
+      this.mappings = mappings;
+    }
+
+    TypeRef exchange(TypeRef original){
+      return exchange(original, true);
+    }
+
+    TypeRef exchange(TypeRef original, boolean throwOnFailedLookup){
+      if (original instanceof TypeParamRef) {
+        String name = ((TypeParamRef) original).getName();
+        TypeRef ref = mappings.get(name);
+        if(ref != null) {
+          return ref;
+        }
+        if(throwOnFailedLookup) {
+          throw new RuntimeException(String.format("Could not find type mapping for parametrized type %s", name));
+        }
+      }
+      return original;
+    }
+
+    static ParameterMap from(ClassRef classRef, ParameterMap parentMappings) {
+      TypeDef def = Types.typeDefFrom(classRef);
+
+      Map<String, TypeRef> mappings = new HashMap<>();
+      for(int i=0; i<def.getParameters().size(); i++) {
+        mappings.put(
+          def.getParameters().get(i).getName(),
+          parentMappings.exchange(classRef.getArguments().get(i))
+        );
+      }
+
+      return new ParameterMap(mappings);
+    }
+  }
 
   private static class PropertyOrAccessor {
     private final Collection<AnnotationRef> annotations;
@@ -515,6 +554,7 @@ private static class PropertyFacade {
     private final List<PropertyOrAccessor> propertyOrAccessors = new ArrayList<>(4);
     private final Set<InternalSchemaSwap> schemaSwaps;
     private final Set<InternalSchemaSwap> matchedSchemaSwaps;
+    private final ParameterMap parameterMap;
     private String renamedTo;
     private String description;
     private String defaultValue;
@@ -530,9 +570,10 @@ private static class PropertyFacade {
     private String descriptionContributedBy;
     private TypeRef schemaFrom;
 
-    public PropertyFacade(Property property, Map<String, Method> potentialAccessors, Set<InternalSchemaSwap> schemaSwaps) {
+    public PropertyFacade(Property property, Map<String, Method> potentialAccessors, Set<InternalSchemaSwap> schemaSwaps, ParameterMap parameterMap) {
       original = property;
       this.schemaSwaps = schemaSwaps;
+      this.parameterMap = parameterMap;
       this.matchedSchemaSwaps = new HashSet<>();
       final String capitalized = property.getNameCapitalized();
       final String name = property.getName();
@@ -610,7 +651,7 @@ public Property process() {
         }
       });
 
-      TypeRef typeRef = schemaFrom != null ? schemaFrom : original.getTypeRef();
+      TypeRef typeRef = schemaFrom != null ? schemaFrom : parameterMap.exchange(original.getTypeRef());
       String finalName = renamedTo != null ? renamedTo : original.getName();
 
       return new Property(original.getAnnotations(), typeRef, finalName,
@@ -685,16 +726,16 @@ private String extractUpdatedNameFromJacksonPropertyIfPresent(Property property)
    * @return the structural schema associated with the specified property
    */
   public T internalFrom(String name, TypeRef typeRef) {
-    return internalFromImpl(name, typeRef, new HashSet<>(), new ArrayList<>());
+    return internalFromImpl(name, typeRef, new HashSet<>(), new ArrayList<>(), new ParameterMap(new HashMap<>()));
   }
 
-  private T internalFromImpl(String name, TypeRef typeRef, Set<String> visited, List<InternalSchemaSwap> schemaSwaps) {
+  private T internalFromImpl(String name, TypeRef typeRef, Set<String> visited, List<InternalSchemaSwap> schemaSwaps, ParameterMap parameterMap) {
     // Note that ordering of the checks here is meaningful: we need to check for complex types last
     // in case some "complex" types are handled specifically
     if (typeRef.getDimensions() > 0 || io.sundr.model.utils.Collections.isCollection(typeRef)) { // Handle Collections & Arrays
       final TypeRef collectionType = TypeAs.combine(TypeAs.UNWRAP_ARRAY_OF, TypeAs.UNWRAP_COLLECTION_OF)
         .apply(typeRef);
-      final T schema = internalFromImpl(name, collectionType, visited, schemaSwaps);
+      final T schema = internalFromImpl(name, parameterMap.exchange(collectionType), visited, schemaSwaps, parameterMap);
       return arrayLikeProperty(schema);
     } else if (io.sundr.model.utils.Collections.IS_MAP.apply(typeRef)) { // Handle Maps
       final TypeRef keyType = TypeAs.UNWRAP_MAP_KEY_OF.apply(typeRef);
@@ -704,15 +745,15 @@ private T internalFromImpl(String name, TypeRef typeRef, Set<String> visited, Li
       }
 
       final TypeRef valueType = TypeAs.UNWRAP_MAP_VALUE_OF.apply(typeRef);
-      T schema = internalFromImpl(name, valueType, visited, schemaSwaps);
+      T schema = internalFromImpl(name, parameterMap.exchange(valueType, false), visited, schemaSwaps, parameterMap);
       if (schema == null) {
         LOGGER.warn("Property '{}' with '{}' value type is mapped to 'object' because its CRD representation cannot be extracted.", name, typeRef);
-        schema = internalFromImpl(name, OBJECT_REF, visited, schemaSwaps);
+        schema = internalFromImpl(name, OBJECT_REF, visited, schemaSwaps, parameterMap);
       }
 
       return mapLikeProperty(schema);
     } else if (io.sundr.model.utils.Optionals.isOptional(typeRef)) { // Handle Optionals
-      return internalFromImpl(name, TypeAs.UNWRAP_OPTIONAL_OF.apply(typeRef), visited, schemaSwaps);
+      return internalFromImpl(name, parameterMap.exchange(TypeAs.UNWRAP_OPTIONAL_OF.apply(typeRef)), visited, schemaSwaps, parameterMap);
     } else {
       final String typeName = COMMON_MAPPINGS.get(typeRef);
       if (typeName != null) { // we have a type that we handle specifically
@@ -724,9 +765,9 @@ private T internalFromImpl(String name, TypeRef typeRef, Set<String> visited, Li
       } else {
         if (typeRef instanceof ClassRef) { // Handle complex types
           ClassRef classRef = (ClassRef) typeRef;
-          TypeDef def = Types.typeDefFrom(classRef);
 
           // check if we're dealing with an enum
+          TypeDef def = Types.typeDefFrom(classRef);
           if (def.isEnum()) {
             final JsonNode[] enumValues = def.getProperties().stream()
               .map(this::extractUpdatedNameFromJacksonPropertyIfPresent)
@@ -735,7 +776,7 @@ private T internalFromImpl(String name, TypeRef typeRef, Set<String> visited, Li
               .toArray(JsonNode[]::new);
             return enumProperty(enumValues);
           } else {
-            return resolveNestedClass(name, def, visited, schemaSwaps);
+            return resolveNestedClass(name, classRef, visited, schemaSwaps, parameterMap);
           }
 
         }
@@ -747,7 +788,8 @@ private T internalFromImpl(String name, TypeRef typeRef, Set<String> visited, Li
   // Flag to detect cycles
   private boolean resolving = false;
 
-  private T resolveNestedClass(String name, TypeDef def, Set<String> visited, List<InternalSchemaSwap> schemaSwaps) {
+  private T resolveNestedClass(String name, ClassRef classRef, Set<String> visited, List<InternalSchemaSwap> schemaSwaps, ParameterMap parameterMap) {
+    TypeDef def = Types.typeDefFrom(classRef);
     if (!resolving) {
       visited.clear();
       resolving = true;
@@ -759,7 +801,7 @@ private T resolveNestedClass(String name, TypeDef def, Set<String> visited, List
       visited.add(visitedName);
     }
 
-    T res = internalFromImpl(def, visited, schemaSwaps);
+    T res = internalFromImpl(def, visited, schemaSwaps, ParameterMap.from(classRef, parameterMap));
     resolving = false;
     return res;
   }

crd-generator/api/src/test/java/io/fabric8/crd/example/generic/Generic.java

@@ -0,0 +1,5 @@
+package io.fabric8.crd.example.generic;
+
+public class Generic<T> {
+  T bar;
+}

crd-generator/api/src/test/java/io/fabric8/crd/example/generic/NestedGeneric.java

@@ -0,0 +1,8 @@
+package io.fabric8.crd.example.generic;
+
+import java.util.List;
+
+public class NestedGeneric<P> {
+  Generic<P> quux;
+  List<P> corge;
+}

crd-generator/api/src/test/java/io/fabric8/crd/example/generic/ResourceWithGeneric.java

@@ -0,0 +1,6 @@
+package io.fabric8.crd.example.generic;
+
+import io.fabric8.kubernetes.client.CustomResource;
+
+public class ResourceWithGeneric  extends CustomResource<ResourceWithGenericSpec, Void> {
+}

crd-generator/api/src/test/java/io/fabric8/crd/example/generic/ResourceWithGenericSpec.java

@@ -0,0 +1,7 @@
+package io.fabric8.crd.example.generic;
+
+public class ResourceWithGenericSpec {
+  Generic<String> foo;
+  Generic<Integer> baz;
+  NestedGeneric<String> qux;
+}

crd-generator/api/src/test/java/io/fabric8/crd/generator/v1/JsonSchemaTest.java

@@ -22,10 +22,12 @@
 import io.fabric8.crd.example.extraction.Extraction;
 import io.fabric8.crd.example.extraction.IncorrectExtraction;
 import io.fabric8.crd.example.extraction.IncorrectExtraction2;
+import io.fabric8.crd.example.generic.ResourceWithGeneric;
 import io.fabric8.crd.example.json.ContainingJson;
 import io.fabric8.crd.example.person.Person;
 import io.fabric8.crd.generator.utils.Types;
 import io.fabric8.kubernetes.api.model.apiextensions.v1.JSONSchemaProps;
+import io.fabric8.kubernetes.api.model.apiextensions.v1.JSONSchemaPropsOrArray;
 import io.sundr.model.TypeDef;
 import org.junit.jupiter.api.Test;
 
@@ -222,6 +224,51 @@ void shouldExtractPropertiesSchemaFromExtractValueAnnotation() {
     assertNull(barProps.get("baz"));
   }
 
+  @Test
+  void shouldProcessGenericClasses() {
+    TypeDef resourceWithGeneric = Types.typeDefFrom(ResourceWithGeneric.class);
+    JSONSchemaProps schema = JsonSchema.from(resourceWithGeneric);
+    assertNotNull(schema);
+
+    Map<String, JSONSchemaProps> properties = schema.getProperties();
+    assertEquals(2, properties.size());
+
+    final JSONSchemaProps specSchema = properties.get("spec");
+    Map<String, JSONSchemaProps> spec = specSchema.getProperties();
+    assertEquals(3, spec.size());
+
+    JSONSchemaProps foo = spec.get("foo");
+    assertNotNull(foo);
+    Map<String, JSONSchemaProps> fooProps = foo.getProperties();
+    assertNotNull(fooProps);
+    assertEquals("string", fooProps.get("bar").getType());
+
+    JSONSchemaProps baz = spec.get("baz");
+    assertNotNull(baz);
+    Map<String, JSONSchemaProps> bazProps = baz.getProperties();
+    assertNotNull(bazProps);
+    assertEquals("integer", bazProps.get("bar").getType());
+
+    JSONSchemaProps qux = spec.get("qux");
+    assertNotNull(qux);
+    Map<String, JSONSchemaProps> quxProps = qux.getProperties();
+    assertEquals(2, quxProps.size());
+
+    JSONSchemaProps quux = quxProps.get("quux");
+    assertNotNull(quux);
+    Map<String, JSONSchemaProps> quuxProps = quux.getProperties();
+    assertNotNull(quuxProps);
+    assertEquals("string", quuxProps.get("bar").getType());
+
+    JSONSchemaProps corge = quxProps.get("corge");
+    assertNotNull(corge);
+    JSONSchemaPropsOrArray corgeItems = corge.getItems();
+    assertNotNull(corgeItems);
+    JSONSchemaProps corgeItemsProps = corgeItems.getSchema();
+    assertNotNull(corgeItemsProps);
+    assertEquals("string", corgeItemsProps.getType());
+  }
+
   @Test
   void shouldThrowIfSchemaSwapHasUnmatchedField() {
     TypeDef incorrectExtraction = Types.typeDefFrom(IncorrectExtraction.class);