chore(tests): Finally add a unit test for RestAPI

Author: DerDackel

src/constructs/load-yaml.ts

@@ -0,0 +1,5 @@
+import fs from 'fs';
+import * as yaml from 'js-yaml';
+import { OpenAPI3 } from 'openapi-typescript';
+
+export const loadYaml = (filename: string) => yaml.load(fs.readFileSync(filename).toString()) as OpenAPI3;

src/constructs/rest-api.ts

@@ -1,4 +1,3 @@
-import * as fs from 'fs';
 import {
   aws_certificatemanager,
   aws_iam,
@@ -8,11 +7,11 @@ import {
 } from 'aws-cdk-lib';
 import * as cdk from 'aws-cdk-lib';
 import { Construct } from 'constructs';
-import * as yaml from 'js-yaml';
 import { OpenAPI3, OperationObject, PathItemObject } from 'openapi-typescript';
 import { ICognitoAuthentication, IJwtAuthentication } from './authentication';
 import { BaseApi, BaseApiProps } from './base-api';
 import { LambdaFunction, LambdaOptions } from './func';
+import { loadYaml } from './load-yaml';
 
 export interface RestApiProps<OPS> extends BaseApiProps {
 
@@ -52,7 +51,7 @@ export class RestApi<PATHS, OPS> extends BaseApi {
   constructor(scope: Construct, id: string, private props: RestApiProps<OPS>) {
     super(scope, id, props);
 
-    this.apiSpec = yaml.load(fs.readFileSync(props.definitionFileName).toString()) as OpenAPI3;
+    this.apiSpec = loadYaml(props.definitionFileName);
 
     let customDomainName: aws_apigateway.DomainNameOptions | undefined;
     if (this.apiFQDN) {
@@ -356,3 +355,4 @@ export class RestApi<PATHS, OPS> extends BaseApi {
   }
 
 }
+

test/constructs/__snapshots__/rest-api.test.ts.snap

@@ -0,0 +1,109 @@
+import { App, Stack } from 'aws-cdk-lib';
+import { Template } from 'aws-cdk-lib/assertions';
+import { Metric, MetricOptions } from 'aws-cdk-lib/aws-cloudwatch';
+import { Permission } from 'aws-cdk-lib/aws-lambda';
+import { Construct } from 'constructs';
+import { OpenAPI3 } from 'openapi-typescript';
+import { LambdaFunction, LambdaFunctionProps, RestApi } from '../../src/constructs';
+import { loadYaml } from '../../src/constructs/load-yaml';
+
+jest.mock('../../src/constructs/load-yaml');
+jest.mock('../../src/constructs/func');
+
+
+describe('A generated RestApi', () => {
+
+  describe('when instantiated with monitoring active', () =>{
+    let stack: Stack;
+    beforeEach(() => {
+      const app = new App();
+      stack = new Stack(app);
+    });
+
+    test('should create a Cloudwatch Dashboard', () => {
+      interface Operations {
+        testEndpoint: {
+          responses: {
+            200: {};
+          };
+        };
+      }
+
+      interface Paths {
+        '/test': {
+          get: Operations['testEndpoint'];
+        };
+      }
+
+      const buffer = {
+        openapi: '3.0.1',
+        paths: {
+          '/test': {
+            get: {
+              operationId: 'testEndpoint',
+              responses: {
+                200: {
+                  content: {
+                    'application/json': {},
+                  },
+                  description: '',
+                  summary: '',
+                },
+              },
+            },
+          },
+        },
+        info: {
+          title: 'Existing API definition',
+          version: '1.0',
+        },
+      } as OpenAPI3;
+
+      jest.mocked(loadYaml).mockReturnValue(buffer);
+      jest.mocked(LambdaFunction).mockImplementation((_scope: Construct, _id: string, _mockProps: LambdaFunctionProps) => {
+        return {
+          metricDuration(_props?: MetricOptions): Metric {
+            return new Metric({
+              metricName: 'Duration',
+              namespace: 'TestNamespace',
+            });
+          },
+          metricInvocations(_props?: MetricOptions): Metric {
+            return new Metric({
+              metricName: 'Invocations',
+              namespace: 'TestNamespace',
+            });
+          },
+          metricErrors(_props?: MetricOptions): Metric {
+            return new Metric({
+              metricName: 'Errors',
+              namespace: 'TestNamespace',
+            });
+          },
+          metricThrottles(_props?: MetricOptions): Metric {
+            return new Metric({
+              metricName: 'Invocations',
+              namespace: 'TestNamespace',
+            });
+          },
+          addPermission(__id: string, __permission: Permission) {
+          },
+        } as LambdaFunction;
+      });
+
+      new RestApi<Paths, Operations>(stack, 'TestSubject', {
+        monitoring: true,
+        apiName: 'TestSubjectApi',
+        definitionFileName: 'someFile',
+        cors: true,
+        stageName: 'test',
+      });
+
+      const template = Template.fromStack(stack);
+
+      expect(template.findResources('AWS::CloudWatch::Dashboard')).toMatchSnapshot();
+
+    });
+  });
+
+});