docs: update 1.test.js with stubbing and proxyquire examples

Author: jescalada

README.md

@@ -91,6 +91,8 @@ customize for your environment, see the [project's documentation](https://git-pr
 - [Quickstart](https://git-proxy.finos.org/docs/category/quickstart/)
 - [Installation](https://git-proxy.finos.org/docs/installation)
 - [Configuration](https://git-proxy.finos.org/docs/category/configuration)
+- [Contributing](https://git-proxy.finos.org/docs/development/contributing)
+- [Testing](https://git-proxy.finos.org/docs/development/testing)
 
 ## Contributing
 

test/1.test.js

@@ -1,24 +1,98 @@
-// This test needs to run first
+/*
+  Template test file. Demonstrates how to:
+  - Use chai-http to test the server
+  - Initialize the server
+  - Stub dependencies with sinon sandbox
+  - Reset stubs after each test
+  - Use proxyquire to replace modules
+  - Clear module cache after a test
+*/
+
 const chai = require('chai');
 const chaiHttp = require('chai-http');
+const sinon = require('sinon');
+const proxyquire = require('proxyquire');
+
 const service = require('../src/service');
+const db = require('../src/db');
+const { readFileSync } = require('fs');
+
+const expect = chai.expect;
 
 chai.use(chaiHttp);
-chai.should();
 
-// Use this test as a template
-describe('init', async () => {
+const TEST_REPO = {
+  project: 'finos',
+  name: 'db-test-repo',
+  url: 'https://github.com/finos/db-test-repo.git',
+};
+
+describe('init', () => {
   let app;
+  let sandbox;
+
+  // Runs before all tests
   before(async function () {
-    app = await service.start(); // pass in proxy if testing config loading or administration of proxy routes
+    // Start the service (can also pass config if testing proxy routes)
+    app = await service.start();
+  });
+
+  // Runs before each test
+  beforeEach(function () {
+    // Create a sandbox for stubbing
+    sandbox = sinon.createSandbox();
+
+    // Example: stub a DB method
+    sandbox.stub(db, 'getRepo').resolves(TEST_REPO);
   });
 
-  it('should not be logged in', async function () {
+  // Example test: check server is running
+  it('should return 401 if not logged in', async function () {
     const res = await chai.request(app).get('/api/auth/profile');
+    expect(res).to.have.status(401);
+  });
+
+  // Example test: check db stub is working
+  it('should get the repo from stubbed db', async function () {
+    const repo = await db.getRepo('finos/db-test-repo');
+    expect(repo).to.deep.equal(TEST_REPO);
+  });
+
+  // Example test: use proxyquire to override the config module
+  it('should return an array of enabled auth methods when overridden', async function () {
+    const fsStub = {
+      readFileSync: sandbox.stub().returns(
+        JSON.stringify({
+          authentication: [
+            { type: 'local', enabled: true },
+            { type: 'ActiveDirectory', enabled: true },
+            { type: 'openidconnect', enabled: true },
+          ],
+        })
+      ),
+    };
+
+    const config = proxyquire('../src/config', {
+      fs: fsStub,
+    });
+    config.initUserConfig();
+    const authMethods = config.getAuthMethods();
+    expect(authMethods).to.have.lengthOf(3);
+    expect(authMethods[0].type).to.equal('local');
+    expect(authMethods[1].type).to.equal('ActiveDirectory');
+    expect(authMethods[2].type).to.equal('openidconnect');
+
+    // Clear config module cache so other tests don't use the stubbed config
+    delete require.cache[require.resolve('../src/config')];
+  });
 
-    res.should.have.status(401);
+  // Runs after each test
+  afterEach(function () {
+    // Restore all stubs in this sandbox
+    sandbox.restore();
   });
 
+  // Runs after all tests
   after(async function () {
     await service.httpServer.close();
   });

website/docs/development/testing.mdx

@@ -168,7 +168,7 @@ Here is an example of a function that resets both of these after each test (`tes
 const clearCache = (sandbox) => {
   delete require.cache[require.resolve('../src/proxy/processors')];
   delete require.cache[require.resolve('../src/proxy/chain')];
-  sandbox.reset();
+  sandbox.restore();
 };
 
 ...
@@ -212,6 +212,10 @@ expect(authMethods[0].type).to.equal('local');
 
 If test coverage is still insufficient after writing your tests, check out the [CodeCov report](https://app.codecov.io/gh/finos/git-proxy) after making the PR and take a look at which lines are missing coverage.
 
+#### More examples
+
+Check out [test/1.test.js](https://github.com/finos/git-proxy/blob/main/test/1.test.js) for another example on how to write unit tests.
+
 ### UI testing with Cypress
 
 Although coverage is currently low, we have introduced Cypress testing to make sure that end-to-end flows are working as expected with every added feature.