Add tests

.gitignore

@@ -2,3 +2,5 @@ dist/
 node_modules/
 data.json
 .idea/
+test-results/
+playwright-report/

README - Tests.md

@@ -0,0 +1,21 @@
+# Introduction
+
+## Scripts
+
+Please check the setup and tests script in package.json
+
+## Parametrization
+
+This demo showcases test parametrization. Tests are basically functions and can have params. This allows us to have a significant volume of test cases covered by a compact volume of code bodies
+
+## Response Validation
+
+This demo showcases using schemas to validate response structures. In real production scenarios we have highly complex structures in responses. Schemas are a standardized and simplified way to validate them
+
+## The problem of Scale VS The problem of troubleshooting in QA Automation
+
+QA Automation has some very standard problems. One such problem is the problem of scale. It is trivial to manage a project with 50 e2e test cases, but 500 is hard and 5000 is a living nightmare. The most obvious way to manage scale is to reuse code. This demo showcases 2 strategies to do that - parametrization and schemas.
+
+Both strategies are completely unnecessary for this test, because the problem we are solving here is super simple. My solution is a showcase
+
+Troubleshooting failing tests is the most common activity in QA. The most common way to waste our budget is to have QA automation where processing test results (this includes re-running, troubleshooting) is a nightmare. A common criticism to strategies I showcase here is that they make troubleshooting harder. There is some truth here. As anything in programing, we are dancing between trade-offs. If this topic is interesting to you, we can dive quite deeper.

package.json

@@ -5,13 +5,16 @@
   "main": "index.js",
   "scripts": {
     "start": "npx tsc && node dist/index.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "setup": "npm install && npx playwright install",
+    "test": "npx playwright test"
   },
   "keywords": [],
   "author": "",
   "license": "ISC",
   "devDependencies": {
+    "@playwright/test": "^1.42.1",
     "@types/node": "^20.14.10",
-    "typescript": "^5.5.3"
+    "typescript": "^5.5.3",
+    "zod": "^3.23.8"
   }
 }

playwright.config.ts

@@ -0,0 +1,48 @@
+import { defineConfig, devices } from '@playwright/test';
+
+/**
+ * Read environment variables from file.
+ * https://github.com/motdotla/dotenv
+ */
+// require('dotenv').config();
+
+/**
+ * See https://playwright.dev/docs/test-configuration.
+ */
+export default defineConfig({
+  testDir: './tests',
+  /* Run tests in files in parallel */
+  fullyParallel: true,
+  /* Fail the build on CI if you accidentally left test.only in the source code. */
+  forbidOnly: !!process.env.CI,
+  /* Retry on CI only */
+  retries: process.env.CI ? 2 : 0,
+  /* Opt out of parallel tests on CI. */
+  workers: process.env.CI ? 1 : undefined,
+  /* Reporter to use. See https://playwright.dev/docs/test-reporters */
+  reporter: [['list'], ['html']],
+  // required because of mailslurp latency
+  timeout: 120000,
+  /* Shared settings for all the projects below. See https://playwright.dev/docs/api/class-testoptions. */
+  use: {
+    /* Base URL, we can set per environment */
+    baseURL: 'http://localhost:3000',
+
+	  /* Maximum timeout for individual interaction, in milliseconds */
+    actionTimeout: 5 * 1000,
+
+    /* Collect trace when retrying the failed test. See https://playwright.dev/docs/trace-viewer */
+    trace: 'on-first-retry',
+  },
+
+  expect: {
+    timeout: 10000,
+  },
+
+  projects: [
+    {
+      name: 'api_tests',
+    },
+  ],
+
+});

tests/demo.spec.ts

@@ -0,0 +1,120 @@
+import { test, expect } from '@playwright/test';
+import { UserSchema, UserListSchema } from './schemas';
+
+test.describe('Basic api tests', () => {
+
+    // The following are few custom validation functions
+    // They validate contents of responses
+    const validateUserList = (res: any) => {
+        expect(res).toMatchObject(
+            { users: [ { name: 'Alice' }, { name: 'Bob' } ] }
+        );
+        expect(res.users.length).toBe(2);
+    }
+
+    const validateUser = (res: any) => {
+        expect(res).toMatchObject(
+            { name: 'Bob' }
+        );
+    }
+
+    // The following is the data for all test cases
+    const TEST_CASES = [
+        {
+            name: "Get All Users",
+            url: "/users",
+            method: "GET",
+            expectedStatus: 200,
+            schema: UserListSchema,
+            customValidation: validateUserList,
+        },
+        {
+            name: "Get Specific User",
+            url: "/users/2",
+            method: "GET",
+            expectedStatus: 200,
+            schema: UserSchema,
+            customValidation: validateUser,
+        },
+        {
+            name: "Get Nonexistent Endpoint",
+            url: "/nonexistent",
+            method: "GET",
+            expectedStatus: 404,
+        },
+        {
+            name: "Get Nonexistent user",
+            url: "/users/22",
+            method: "GET",
+            expectedStatus: 404,
+        },
+        {
+            name: "Create user - unsupported",
+            url: "/users",
+            method: "POST",
+            expectedStatus: 404,
+        },
+        {
+            name: "Update user - unsupported",
+            url: "/users/2",
+            method: "PUT",
+            expectedStatus: 404,
+        },
+        {
+            name: "DELETE user - unsupported",
+            url: "/users/2",
+            method: "DELETE",
+            expectedStatus: 404,
+        },
+        {
+            name: "Get Health",
+            url: "/health",
+            method: "GET",
+            expectedStatus: 200,
+            expectedNonJsonText: "OK",
+        },
+    ]
+    for (const params of TEST_CASES) {
+        test(`Scenario: ${params.name}`, async ({ request}) => {
+            // Send Request
+            let response;    
+            switch (params.method) {
+                case 'GET':
+                    response = await request.get(params.url);
+                    break;
+                case 'POST':
+                    response = await request.post(params.url);
+                    break;
+                case 'PUT':
+                    response = await request.put(params.url);
+                    break;
+                case 'DELETE':
+                    response = await request.delete(params.url);
+                    break;
+                default:
+                    throw new Error(`Unsupported HTTP method: ${params.method}`);
+            }
+
+            // Check Status Code
+            expect(response.status()).toBe(params.expectedStatus);
+
+            // Validate Schema, optional param
+            if (params.schema !== undefined) {
+                const res = await response.json();
+                params.schema.parse(res);
+            }
+
+            // Additional custom validation, optional param
+            if (params.customValidation !== undefined) {
+                const res = await response.json();
+                params.customValidation(res);
+            }
+
+            // Some endpoints return plain text, optional param
+            if (params.expectedNonJsonText !== undefined) {
+                const actualText = await response.text();
+                expect(actualText).toBe(params.expectedNonJsonText);
+            }
+        });
+    }
+});

tests/schemas.ts

@@ -0,0 +1,12 @@
+import { z } from 'zod';
+
+// User
+export const UserSchema = z.object({
+    id: z.string(),
+    name: z.string(),
+});
+
+// List of users
+export const UserListSchema = z.object({
+    users: z.array(UserSchema),
+});

tsconfig.json

@@ -3,7 +3,7 @@
     "target": "ES6",
     "module": "commonjs",
     "outDir": "./dist",
-    "rootDir": "./src",
+    "rootDirs": ["./src", "./tests"],
     "strict": true,
     "esModuleInterop": true
   }