test/add test on get user pkg manager (#349)

* chore: make possible to write tests aside with implementations

* test: write getUserPkgManager test TO-DOs

* test: add test to building the path

* test: add tests to manual file checking

* test: add tests to npm_config_user_agent

* Update packages/cli/src/utils/getUserPkgManager.spec.ts

packages/cli/jest.config.js

@@ -2,5 +2,9 @@
 export default {
   preset: 'ts-jest',
   testEnvironment: 'node',
-  testMatch: ["<rootDir>/test/**/*.ts?(x)", "<rootDir>/test/**/?(*.)+(spec|test).ts?(x)"],
+  testMatch: [
+    "<rootDir>/test/**/*.ts?(x)",
+    "<rootDir>/test/**/?(*.)+(spec|test).ts?(x)",
+    "<rootDir>/src/**/?(*.)+(spec|test).ts?(x)"
+  ],
 };

packages/cli/src/utils/getUserPkgManager.spec.ts

@@ -0,0 +1,96 @@
+import { randomUUID } from "crypto";
+import { pathExists } from "./fileSystem";
+import { getUserPackageManager } from "./getUserPkgManager";
+import * as pathModule from "path";
+
+jest.mock('path', () => ({
+  join: jest.fn().mockImplementation((...paths: string[]) => paths.join('/')),
+}))
+
+jest.mock('./fileSystem', () => ({
+  pathExists: jest.fn().mockResolvedValue(false),
+}));
+
+describe(getUserPackageManager.name, () => {
+  let path: string;
+
+  beforeEach(() => {
+    path = randomUUID();
+  });
+
+  afterEach(jest.clearAllMocks);
+
+  describe(`should use ${pathExists.name} to check for package manager artifacts`, () => {
+    it('should join the path with the artifact name', async () => {
+      await getUserPackageManager(path);
+
+      expect(pathModule.join).toBeCalledWith(path, 'yarn.lock');
+      expect(pathModule.join).toBeCalledWith(path, 'pnpm-lock.yaml');
+      expect(pathModule.join).toBeCalledWith(path, 'package-lock.json');
+    });
+
+    it(`should call ${pathExists.name} with the path.join result`, async () => {
+      const expected = randomUUID();
+
+      (pathModule.join as jest.Mock).mockReturnValueOnce(expected);
+
+      await getUserPackageManager(path);
+
+      expect(pathExists).toBeCalledWith(expected);
+    });
+
+    it('should return "yarn" if yarn.lock exists', async () => {
+      (pathExists as jest.Mock).mockImplementation((path: string) => path.endsWith('yarn.lock'));
+
+      expect(await getUserPackageManager(path)).toBe('yarn');
+    });
+
+    it('should return "pnpm" if pnpm-lock.yaml exists', async () => {
+      (pathExists as jest.Mock).mockImplementation(async (path: string) => path.endsWith('pnpm-lock.yaml'));
+
+      expect(await getUserPackageManager(path)).toBe('pnpm');
+    });
+
+    it('should return "npm" if package-lock.json exists', async () => {
+      (pathExists as jest.Mock).mockImplementation((path: string) => path.endsWith('package-lock.json'));
+
+      expect(await getUserPackageManager(path)).toBe('npm');
+    });
+
+    it('should return "npm" if npm-shrinkwrap.json exists', async () => {
+      (pathExists as jest.Mock).mockImplementation((path: string) => path.endsWith('npm-shrinkwrap.json'));
+
+      expect(await getUserPackageManager(path)).toBe('npm');
+    });
+  });
+
+  describe(`if doesn't found artifacts, should use process.env.npm_config_user_agent to detect package manager`, () => {
+    beforeEach(() => {
+      (pathExists as jest.Mock).mockResolvedValue(false);
+    })
+
+    it('should return "yarn" if process.env.npm_config_user_agent starts with "yarn"', async () => {
+      process.env.npm_config_user_agent = 'yarn';
+
+      expect(await getUserPackageManager(path)).toBe('yarn');
+    });
+
+    it('should return "pnpm" if process.env.npm_config_user_agent starts with "pnpm"', async () => {
+      process.env.npm_config_user_agent = 'pnpm';
+
+      expect(await getUserPackageManager(path)).toBe('pnpm');
+    });
+
+    it('if doesn\'t start with "yarn" or "pnpm", should return "npm"', async () => {
+      process.env.npm_config_user_agent = randomUUID();
+
+      expect(await getUserPackageManager(path)).toBe('npm');
+    });
+
+    it('should return "npm" if process.env.npm_config_user_agent is not set', async () => {
+      delete process.env.npm_config_user_agent;
+
+      expect(await getUserPackageManager(path)).toBe('npm');
+    });
+  });
+})