screenshotter implemented

package.json

@@ -24,6 +24,7 @@
     "@nestjs/common": "^9.0.0",
     "@nestjs/core": "^9.0.0",
     "@nestjs/platform-express": "^9.0.0",
+    "puppeteer": "^15.3.2",
     "reflect-metadata": "^0.1.13",
     "rimraf": "^3.0.2",
     "rxjs": "^7.2.0"
@@ -34,6 +35,7 @@
     "@nestjs/testing": "^9.0.0",
     "@types/express": "^4.17.13",
     "@types/jest": "28.1.4",
+    "@types/jest-image-snapshot": "^5.1.0",
     "@types/node": "^16.0.0",
     "@types/supertest": "^2.0.11",
     "@typescript-eslint/eslint-plugin": "^5.0.0",
@@ -42,6 +44,7 @@
     "eslint-config-prettier": "^8.3.0",
     "eslint-plugin-prettier": "^4.0.0",
     "jest": "28.1.2",
+    "jest-image-snapshot": "^5.1.0",
     "prettier": "^2.3.2",
     "source-map-support": "^0.5.20",
     "supertest": "^6.1.3",
@@ -65,6 +68,7 @@
     "collectCoverageFrom": [
       "**/*.(t|j)s"
     ],
+    "setupFilesAfterEnv": ["<rootDir>/setup.jest.ts"],
     "coverageDirectory": "../coverage",
     "testEnvironment": "node"
   }

src/app.module.ts

@@ -1,10 +1,11 @@
 import { Module } from '@nestjs/common';
 import { HelloWorldController } from './hello-world/controller';
 import { HelloWorldService } from './hello-world/service';
+import { ScreenshotterService } from './screenshotter/screenshotter.service';
 
 @Module({
   imports: [],
   controllers: [HelloWorldController],
-  providers: [HelloWorldService],
+  providers: [HelloWorldService, ScreenshotterService],
 })
 export class AppModule {}

src/screenshotter/screenshotter.service.spec.ts

@@ -0,0 +1,26 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { ScreenshotterService } from './screenshotter.service';
+
+describe('ScreenshotterService', () => {
+  let service: ScreenshotterService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [ScreenshotterService],
+    }).compile();
+
+    service = module.get<ScreenshotterService>(ScreenshotterService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+
+  it('should return "Hello World!" screenshot', async () => {
+    const image = await service.takeScreenshot({
+      imageType: 'png',
+      url: new URL('data:text/html,%3Ch1%3EHello%2C%20World%21%3C%2Fh1%3E'),
+    })
+    expect(image).toMatchImageSnapshot()
+  });
+});

src/screenshotter/screenshotter.service.ts

@@ -0,0 +1,26 @@
+import { Injectable } from '@nestjs/common';
+import puppeteer from 'puppeteer'
+
+type TakeScreenshotOptions = {
+  imageType: 'jpeg' | 'png'
+  url: URL
+}
+
+@Injectable()
+export class ScreenshotterService {
+  async takeScreenshot(options: TakeScreenshotOptions): Promise<Buffer> {
+    const browser = await puppeteer.launch()
+    try {
+      const page = await browser.newPage()
+      await page.goto(options.url.toString())
+      const image = await page.screenshot({
+        type: options.imageType,
+        encoding: 'binary'
+      }) as Buffer
+
+      return image
+    } finally {
+      browser.close()
+    }
+  }
+}

src/setup.jest.ts

@@ -0,0 +1,3 @@
+const { toMatchImageSnapshot } = require('jest-image-snapshot');
+
+expect.extend({ toMatchImageSnapshot });

tsconfig.build.json

@@ -1,4 +1,4 @@
 {
   "extends": "./tsconfig.json",
-  "exclude": ["node_modules", "test", "dist", "**/*spec.ts"]
+  "exclude": ["node_modules", "test", "dist", "**/*spec.ts", "**/*jest.ts"]
 }