Merge inherited type properties. Fixes #41

Author: ngraef

src/metadata/resolveType.ts

@@ -238,7 +238,7 @@ function getReferenceType(type: ts.EntityName, genericTypeMap?: Map<String, ts.T
         }
 
         const extendedProperties = getInheritedProperties(modelTypeDeclaration, genericTypes);
-        referenceType.properties = referenceType.properties.concat(extendedProperties);
+        mergeReferenceTypeProperties(referenceType.properties, extendedProperties);
 
         localReferenceTypeCache[typeNameWithGenerics] = referenceType;
 
@@ -249,6 +249,17 @@ function getReferenceType(type: ts.EntityName, genericTypeMap?: Map<String, ts.T
     }
 }
 
+function mergeReferenceTypeProperties(properties: Property[], extendedProperties: Property[]) {
+    extendedProperties.forEach(prop => {
+        const existingProp = properties.find(p => p.name === prop.name);
+        if (existingProp) {
+            existingProp.description = existingProp.description || prop.description;
+        } else {
+            properties.push(prop);
+        }
+    });
+}
+
 function resolveFqTypeName(type: ts.EntityName): string {
     if (type.kind === ts.SyntaxKind.Identifier) {
         return (type as ts.Identifier).text;

test/data/apis.ts

@@ -328,3 +328,23 @@ export class ParameterizedEndpoint {
         return new PrimitiveClassModel();
     }
 }
+
+export abstract class Entity {
+    /**
+     * A numeric identifier
+     */
+    id?: number;
+}
+
+export class NamedEntity implements Entity {
+    id: number;
+    name: string;
+}
+
+@Path('abstract')
+export class AbstractEntityEndpoint {
+    @GET
+    get(): NamedEntity {
+        return new NamedEntity();
+    }
+}

test/unit/definitions.spec.ts

@@ -284,4 +284,16 @@ describe('Definition generation', () => {
       expect(expression.evaluate(spec)).to.eq('path');
       });
   });
+
+  describe('AbstractEntityEndpoint', () => {
+    it('should not duplicate inherited properties in the required list', () => {
+      const expression = jsonata('definitions.NamedEntity.required');
+      expect(expression.evaluate(spec)).to.deep.equal(['id', 'name']);
+    });
+
+    it('should use property description from base class if not defined in child', () => {
+      const expression = jsonata('definitions.NamedEntity.properties.id.description');
+      expect(expression.evaluate(spec)).to.eq('A numeric identifier');
+    });
+  });
 });