SLSCMN-4 error handler tests

src/middlewares/error-handler-http.test.ts

@@ -0,0 +1,140 @@
+import { Request } from '@middy/core';
+import { jest } from '@jest/globals';
+
+import { HttpError, ServiceError } from '../errors';
+
+import { httpErrorHandler } from './error-handler-http';
+import { requestFixture } from '../__fixtures__/middy.fixture';
+
+describe('HttpErrorHandler', () => {
+  it('should create the middleware', () => {
+    const middleware = httpErrorHandler();
+
+    expect(middleware.before).not.toBeDefined();
+    expect(middleware.after).not.toBeDefined();
+    expect(middleware.onError).toBeDefined();
+  });
+
+  it('should do nothing when response has been written', () => {
+    const response = JSON.stringify({ foo: 'bar' });
+    const request: Request = {
+      ...requestFixture,
+      response,
+    };
+
+    const middleware = httpErrorHandler();
+
+    expect(middleware.onError).toBeDefined();
+
+    middleware.onError?.(request);
+
+    expect(request.response).toBe(response);
+  });
+
+  it('should do nothing when no error', () => {
+    const request: Request = {
+      ...requestFixture,
+    };
+    delete request.response;
+
+    const middleware = httpErrorHandler();
+
+    expect(middleware.onError).toBeDefined();
+
+    middleware.onError?.(request);
+
+    expect(request.response).not.toBeDefined();
+  });
+
+  it('should write log when logger provided', () => {
+    type loggerFn = (msg: string) => void;
+    const mockLogger = jest.fn<loggerFn>();
+    const request: Request = {
+      ...requestFixture,
+      error: new HttpError('message', 404),
+    };
+    delete request.response;
+
+    const middleware = httpErrorHandler({
+      defaultMessage: 'message',
+      defaultStatusCode: 500,
+      logger: mockLogger,
+    });
+
+    expect(middleware.onError).toBeDefined();
+
+    middleware.onError?.(request);
+
+    expect(mockLogger).toHaveBeenCalled();
+  });
+
+  it('should handle HttpError', () => {
+    const expectedResponse = {
+      body: JSON.stringify({ name: 'HttpError', message: 'message', code: 500, statusCode: 500 }),
+      statusCode: 500,
+    };
+    const request: Request = {
+      ...requestFixture,
+      error: new HttpError('message', 500),
+    };
+    delete request.response;
+
+    const middleware = httpErrorHandler();
+
+    expect(middleware.onError).toBeDefined();
+
+    middleware.onError?.(request);
+
+    expect(request.response).toStrictEqual(expectedResponse);
+  });
+
+  it('should handle ServiceError', () => {
+    const expectedResponse = {
+      body: JSON.stringify({
+        name: 'ServiceError',
+        message: 'message',
+        code: 500,
+        statusCode: 500,
+      }),
+      statusCode: 500,
+    };
+    const request: Request = {
+      ...requestFixture,
+      error: new ServiceError('message'),
+    };
+    delete request.response;
+
+    const middleware = httpErrorHandler();
+
+    expect(middleware.onError).toBeDefined();
+
+    middleware.onError?.(request);
+
+    expect(request.response).toStrictEqual(expectedResponse);
+  });
+
+  it('should handle Error', () => {
+    const expectedResponse = {
+      body: JSON.stringify({
+        name: 'Error',
+        message: 'message',
+        code: 500,
+        statusCode: 500,
+      }),
+      statusCode: 500,
+    };
+    const request: Request = {
+      ...requestFixture,
+      error: new Error('message'),
+    };
+    delete request.response;
+
+    const middleware = httpErrorHandler();
+
+    expect(middleware.onError).toBeDefined();
+
+    middleware.onError?.(request);
+
+    expect(request.response).toStrictEqual(expectedResponse);
+  });
+});