Fix param examples incorrectly made into arrays

packages/cli/src/metadataGeneration/parameterGenerator.ts

@@ -134,7 +134,10 @@ export class ParameterGenerator {
     if (!this.supportBodyMethod(this.method)) {
       throw new GenerateMetadataError(`@BodyProp('${parameterName}') Can't support in ${this.method.toUpperCase()} method.`);
     }
-    const { examples: example, exampleLabels } = this.getParameterExample(parameter, parameterName);
+
+    const { examples, exampleLabels } = this.getParameterExample(parameter, parameterName);
+    const example = examples?.length ? examples[0] : undefined
+
     return {
       default: getInitializerValue(parameter.initializer, this.current.typeChecker, type),
       description: this.getParameterDescription(parameter),

tests/unit/swagger/definitionsGeneration/metadata.spec.ts

@@ -757,8 +757,13 @@ describe('Metadata generation', () => {
       expect(parameter.parameterName).to.equal('firstname');
       expect(parameter.required).to.be.true;
       expect(parameter.example).not.to.be.undefined;
-      expect(parameter.example).to.deep.equal(['name1', 'name2']);
-      expect((parameter.example as unknown[]).length).to.be.equal(2);
+      /**
+       * Multiple example values per property are not allowed.
+       * Putting them into an array is *not* the intended behavior
+       * {@link https://swagger.io/docs/specification/2-0/adding-examples/}
+       */
+      // expect(parameter.example).to.deep.equal(['name1', 'name2']);
+      // expect((parameter.example as unknown[]).length).to.be.equal(2);
     });
 
     it('should generate a res parameter and the corresponding additional response', () => {

tests/unit/swagger/schemaDetails3.spec.ts

@@ -393,6 +393,19 @@ describe('Definition generation for OpenAPI 3.0.0', () => {
       });
     });
 
+    describe('should generate single example for @BodyProp parameters', () => {
+      it('Single @BodyProp parameter in Post method', () => {
+        const postBodyParams = exampleSpec.paths['/ExampleTest/post_body_prop_single'].post?.requestBody?.content?.['application/json'];
+        expect(postBodyParams?.schema?.properties?.prop1?.example).to.equal('prop1');
+      });
+
+      it('Two @BodyProp parameters in Post method', () => {
+        const postBodyParams = exampleSpec.paths['/ExampleTest/post_body_prop'].post?.requestBody?.content?.['application/json'];
+        expect(postBodyParams?.schema?.properties?.prop1?.example).to.equal('prop1_1');
+        expect(postBodyParams?.schema?.properties?.prop2?.example).to.equal('prop2_1');
+      });
+    })
+
     it('Supports custom example labels', () => {
       const metadata = new MetadataGenerator('./fixtures/controllers/exampleController.ts').Generate();
       const exampleSpec = new SpecGenerator3(metadata, getDefaultExtendedOptions()).GetSpec();