feat(appsync): add x-ray parameter to AppSync (#9389)

Close: #7640

- [x] Adding a boolean prop for xrayEnabled
- [x]  Linking it to the xrayEnabled prop in class CfnGraphQLApi from appsync.generated.ts file that is generated on yarn build
- [x]  Writing a unit test to check whether that the boolean property is set in the CloudFormation Template
----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-appsync/README.md

@@ -54,6 +54,7 @@ const api = new appsync.GraphQLApi(stack, 'Api', {
       authorizationType: appsync.AuthorizationType.IAM
     },
   },
+  xrayEnabled: true,
 });
 
 const demoTable = new db.Table(stack, 'DemoTable', {
@@ -159,4 +160,4 @@ api.grantMutation(role, 'updateExample');
 
 // For custom types and granular design
 api.grant(role, appsync.IamResource.ofType('Mutation', 'updateExample'), 'appsync:GraphQL');
-```
+```

packages/@aws-cdk/aws-appsync/lib/graphqlapi.ts

@@ -256,6 +256,12 @@ export interface GraphQLApiProps {
    * @default - Use schemaDefinition
    */
   readonly schemaDefinitionFile?: string;
+  /**
+   * A flag indicating whether or not X-Ray tracing is enabled for the GraphQL API.
+   *
+   * @default - false
+   */
+  readonly xrayEnabled?: boolean;
 
 }
 
@@ -402,6 +408,7 @@ export class GraphQLApi extends Construct {
           )
           : undefined,
       additionalAuthenticationProviders: this.formatAdditionalAuthenticationProviders(props),
+      xrayEnabled: props.xrayEnabled,
     });
 
     this.apiId = this.api.attrApiId;

packages/@aws-cdk/aws-appsync/test/appsync.test.ts

@@ -94,4 +94,23 @@ test('appsync should configure resolver as unit when pipelineConfig is empty arr
   expect(stack).toHaveResourceLike('AWS::AppSync::Resolver', {
     Kind: 'UNIT',
   });
-});
+});
+
+test('when xray is enabled should not throw an Error', () => {
+  // GIVEN
+  const stack = new cdk.Stack();
+
+  // WHEN
+  new appsync.GraphQLApi(stack, 'api', {
+    authorizationConfig: {},
+    name: 'api',
+    schemaDefinition: appsync.SchemaDefinition.FILE,
+    schemaDefinitionFile: path.join(__dirname, 'appsync.test.graphql'),
+    xrayEnabled: true,
+  });
+
+  // THEN
+  expect(stack).toHaveResourceLike('AWS::AppSync::GraphQLApi', {
+    XrayEnabled: true,
+  });
+});