Automatically Detect Package Manager (#17)

Co-authored-by: Eric Jacobson <ejacobson@wayfair.com>

CHANGELOG.md

@@ -13,6 +13,12 @@ This changelog format is largely based on [Keep A Changelog](https://keepachange
 
 #### 🔨 Chores & Documentation
 
+## [0.2.0] - 2022-05-16
+
+#### 🚀 New Features & Enhancements
+
+- Detect package manager based on lockfile
+
 ## [0.1.3] - 2022-05-03
 
 #### 🔨 Chores & Documentation

ONE-VERSION.md

@@ -58,3 +58,4 @@ Although using the same specifier, the entries resolve to two different versions
 
 - This library currently only operates on declared dependencies. That is the `dependencies`, `devDependencies`, and `peerDependencies` specified by a workspace - **not** any transitive dependencies.
 - Resolutions are not yet taken into account.
+- Package manager is selected based on the lockfile name in the root of the repo.

README.md

@@ -63,14 +63,12 @@ Add the following section to your package.json:
 ```json
 {
   "scripts": {
-    "one-version:check": "one-version check -p ${yarn | pnpm}"
+    "one-version:check": "one-version check"
   }
 }
 
 ```
 
-The `-p` flag is not required if using `pnpm`.
-
 Run `yarn one-version:check` or `pnpm run one-version:check`.
 
 If the repo is compliant, the tool will print this message:
@@ -97,13 +95,20 @@ prettier
 
 The behavior of `@wayfair/one-version` can be configured by a `one-version.config.json` at the root of the repository.
 
-The only configuration this currently supports is an object of dependency `overrides`. This may be useful while performing major upgrades.
+### Supported Options
+
+#### overrides (optional, object)
 
-```js
+Overrides lets workspaces opt out of the one-version rule. This may be useful while performing major upgrades.
 
-"overrides": {
-  dependency: {
-    versionSpecifier: [workspaceA, workspaceB]
+### Examples
+
+```json
+{
+  "overrides": {
+    "dependency": {
+      "versionSpecifier": ["workspaceA", "workspaceB"]
+    }
   }
 }
 ```

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@wayfair/one-version",
-  "version": "0.1.3",
+  "version": "0.2.0",
   "description": "Opinionated Monorepo Dependency Management CLI",
   "bin": "src/index.js",
   "main": "src/index.js",

src/__tests__/check.test.js

@@ -2,30 +2,54 @@ const { check } = require("../check");
 const {
   NO_CHECK_API_ERROR,
   FAILED_CHECK_ERROR,
+  UNABLE_TO_DETECT_PACKAGE_MANAGER_ERROR,
 } = require("../shared/constants");
 
 const packageManager = "fake-package-manager";
+const otherPackageManager = "other-package-manager";
 
-const mockGetConfig = () => ({ overrides: {} });
+const mockGetConfig = () => ({
+  overrides: {},
+  packageManager: otherPackageManager,
+});
 const mockGetMissingPackageApi = () => {};
 
 describe("one-version: check", () => {
-  it("throws if package manager specified does not have check api", () => {
+  it("throws if package manager is not supported", () => {
+    const mockDetectPackageManager = jest.fn();
+    mockDetectPackageManager.mockReturnValue("");
+
+    expect(() => {
+      check({
+        getPackageManager: mockDetectPackageManager,
+        getConfig: mockGetConfig,
+        getCheckApi: mockGetMissingPackageApi,
+      });
+    }).toThrow(`${UNABLE_TO_DETECT_PACKAGE_MANAGER_ERROR}`);
+  });
+
+  it("throws if package manager detected does not have check api", () => {
+    const mockDetectPackageManager = jest.fn();
+    mockDetectPackageManager.mockReturnValue(packageManager);
+
     expect(() => {
       check({
-        packageManager,
+        getPackageManager: mockDetectPackageManager,
         getConfig: mockGetConfig,
         getCheckApi: mockGetMissingPackageApi,
       });
     }).toThrow(`${NO_CHECK_API_ERROR} ${packageManager}`);
   });
 
   it("calls check api if found for package manager", () => {
+    const mockDetectPackageManager = jest.fn();
+    mockDetectPackageManager.mockReturnValue(packageManager);
+
     const mockCheckApi = jest.fn();
     mockCheckApi.mockReturnValue({ duplicateDependencies: [] });
 
     check({
-      packageManager,
+      getPackageManager: mockDetectPackageManager,
       getConfig: mockGetConfig,
       getCheckApi: () => mockCheckApi,
     });
@@ -34,12 +58,15 @@ describe("one-version: check", () => {
   });
 
   it("throws if check api finds duplicate dependencies", () => {
+    const mockDetectPackageManager = jest.fn();
+    mockDetectPackageManager.mockReturnValue(packageManager);
+
     const mockCheckApi = jest.fn();
     mockCheckApi.mockReturnValue({ duplicateDependencies: ["foo"] });
 
     expect(() => {
       check({
-        packageManager,
+        getPackageManager: mockDetectPackageManager,
         getConfig: mockGetConfig,
         getCheckApi: () => mockCheckApi,
         prettify: () => {},

src/check.js

@@ -3,11 +3,12 @@ Enforcing only one version of any direct dependency is specified in the repo.
 Note: Currently enforces the specifications match exactly, i.e. `^17` != `17`.
 */
 const chalk = require("chalk");
-const { parseConfig } = require("./shared/util");
+const { parseConfig, detectPackageManager } = require("./shared/util");
 const { format } = require("./format-output");
 const { checkYarn } = require("./yarn/check");
 const { checkPnpm } = require("./pnpm/check");
 const {
+  UNABLE_TO_DETECT_PACKAGE_MANAGER_ERROR,
   FAILED_CHECK_ERROR,
   NO_CHECK_API_ERROR,
 } = require("./shared/constants");
@@ -22,15 +23,20 @@ const getCheckPackageApi = (packageManager) => {
 };
 
 const check = ({
-  packageManager,
+  getPackageManager = detectPackageManager,
   getConfig = parseConfig,
   getCheckApi = getCheckPackageApi,
   prettify = format,
 } = {}) => {
+  const { overrides } = getConfig();
+
+  const packageManager = getPackageManager();
+  if (!packageManager) {
+    throw new Error(UNABLE_TO_DETECT_PACKAGE_MANAGER_ERROR);
+  }
+
   const checkApi = getCheckApi(packageManager);
   if (checkApi) {
-    const { overrides } = getConfig();
-
     const { duplicateDependencies } = checkApi({
       overrides,
     });

src/index.js

@@ -16,10 +16,9 @@ program
   .description(
     "Verify that only one version of each dependency exists in a monorepo"
   )
-  .option("-p, --packageManager <type>", "package manager", "pnpm")
-  .action(({ packageManager }) => {
+  .action(() => {
     try {
-      check({ packageManager });
+      check();
     } catch (e) {
       console.log(chalk.red(e.message));
       process.exit(1);

src/shared/__tests__/util.test.js

@@ -2,7 +2,14 @@ const {
   getPackageDeps,
   transformDependencies,
   findDuplicateDependencies,
+  detectPackageManager,
 } = require("../util");
+const fs = require("fs");
+
+jest.mock('fs', () => ({
+  ...jest.requireActual('fs'),
+  existsSync: jest.fn(),
+}));
 
 const MOCK_TRANSFORMED_DEPENDENCIES = {
   eslint: { "7.0.1": { direct: ["mock-app-a", "mock-app-b", "mock-app-c"] } },
@@ -118,4 +125,22 @@ describe("findDuplicateDependencies", () => {
       ],
     ]);
   });
+
+  it("returns pnpm if pnpm-lock.yml exists", () => {
+    fs.existsSync.mockReturnValueOnce(true);
+    const packageManager = detectPackageManager({pnpm: "pnpm-lock.yaml",});
+    expect(packageManager).toBe('pnpm');
+  });
+
+  it("returns pnpm if yarn.lock exists", () => {
+    fs.existsSync.mockReturnValueOnce(true);
+    const packageManager = detectPackageManager({yarn: "yarn.lock"});
+    expect(packageManager).toBe('yarn');
+  });
+
+  it("returns empty if package manager is not detected", () => {
+    fs.existsSync.mockReturnValueOnce(true);
+    const packageManager = detectPackageManager({});
+    expect(packageManager).toBe('');
+  });
 });

src/shared/constants.js

@@ -1,18 +1,27 @@
 const CONFIG_FILE = "oneversion.config.json";
 
+const LOCKFILES = {
+  yarn: "yarn.lock",
+  pnpm: "pnpm-lock.yaml",
+};
+
 const DEPENDENCY_TYPES = {
   DIRECT: "direct",
   PEER: "peer",
   DEV: "dev",
 };
 
+const UNABLE_TO_DETECT_PACKAGE_MANAGER_ERROR =
+  "Unable to detect a package manager. Try installing dependencies.";
 const FAILED_CHECK_ERROR =
   "More than one version of dependencies found. See above output.";
 const NO_CHECK_API_ERROR = `'check' api not supported for package manager:`;
 
 module.exports = {
   CONFIG_FILE,
+  LOCKFILES,
   DEPENDENCY_TYPES,
+  UNABLE_TO_DETECT_PACKAGE_MANAGER_ERROR,
   FAILED_CHECK_ERROR,
   NO_CHECK_API_ERROR,
 };

src/shared/util.js

@@ -1,6 +1,6 @@
 const { readFileSync, existsSync } = require("fs");
 const path = require("path");
-const { DEPENDENCY_TYPES, CONFIG_FILE } = require("./constants");
+const { DEPENDENCY_TYPES, CONFIG_FILE, LOCKFILES } = require("./constants");
 
 /**
  * Parse a config file if it exists
@@ -155,9 +155,22 @@ const findDuplicateDependencies = (dependencies, overrides) => {
     .filter(([, versions]) => Object.keys(versions).length > 1);
 };
 
+/**
+ * Detect the package manager being used by the project
+ */
+const detectPackageManager = (lockfiles = LOCKFILES) => {
+  for (const [packageManager, lockfile] of Object.entries(lockfiles)) {
+    if (existsSync(lockfile)) {
+      return packageManager;
+    }
+  }
+  return "";
+};
+
 module.exports = {
   parseConfig,
   getPackageDeps,
   transformDependencies,
   findDuplicateDependencies,
+  detectPackageManager,
 };