feat: detect alternative package managers based on lockfile

If a package manager is not explicitly set in config.json or passed-in via argv/env, NodeBB will now check for the presence of alternative package managers' lockfiles and adjust the package manager to-be-used accordingly. If the standard npm lockfile exists, npm will always be used.

src/cli/package-install.js

@@ -53,15 +53,44 @@ pkgInstall.supportedPackageManager = [
 ];
 
 pkgInstall.getPackageManager = () => {
-	// Use this method if you can't reliably require('nconf') directly
 	try {
-		// Quick & dirty nconf setup
 		fs.accessSync(path.join(paths.nodeModules, 'nconf/package.json'), fs.constants.R_OK);
 		const nconf = require('nconf');
-		const configFile = path.resolve(__dirname, '../../', nconf.any(['config', 'CONFIG']) || 'config.json');
-		nconf.env().file({ // not sure why adding .argv() causes the process to terminate
-			file: configFile,
-		});
+		if (!Object.keys(nconf.stores).length) {
+			// Quick & dirty nconf setup for when you cannot rely on nconf having been required already
+			const configFile = path.resolve(__dirname, '../../', nconf.any(['config', 'CONFIG']) || 'config.json');
+			nconf.env().file({ // not sure why adding .argv() causes the process to terminate
+				file: configFile,
+			});
+		}
+
+		if (nconf.get('package_manager') && !pkgInstall.supportedPackageManager.includes(nconf.get('package_manager'))) {
+			nconf.clear('package_manager');
+		}
+
+		if (!nconf.get('package_manager')) {
+			// Best guess based on lockfile detection
+			try {
+				// use npm if lockfile present
+				fs.accessSync(path.resolve(__dirname, '../../package-lock.json'), fs.constants.R_OK);
+			} catch (e) {
+				nconf.set('package_manager', [
+					// no cnpm detection as it uses same lockfile as npm
+					'yarn.lock', 'pnpm-lock.yaml',
+				].reduce((result, cur) => {
+					if (result) {
+						return result;
+					}
+
+					try {
+						fs.accessSync(path.resolve(__dirname, `../../${cur}`), fs.constants.R_OK);
+						return cur.slice(0, 4);
+					} catch (e) {
+						return result;
+					}
+				}, undefined));
+			}
+		}
 
 		return nconf.get('package_manager') || 'npm';
 	} catch (e) {

src/cli/upgrade-plugins.js

@@ -6,16 +6,13 @@ const cproc = require('child_process');
 const semver = require('semver');
 const fs = require('fs');
 const path = require('path');
-const nconf = require('nconf');
 const chalk = require('chalk');
 
 const { paths, pluginNamePattern } = require('../constants');
+const pkgInstall = require('./package-install');
 
-const packageManager = nconf.get('package_manager');
-
-const supportedPackageManagerList = require('./package-install').supportedPackageManager; // load config from src/cli/package-install.js
-
-let packageManagerExecutable = supportedPackageManagerList.indexOf(packageManager) >= 0 ? packageManager : 'npm';
+const packageManager = pkgInstall.getPackageManager();
+let packageManagerExecutable = packageManager;
 const packageManagerInstallArgs = packageManager === 'yarn' ? ['add'] : ['install', '--save'];
 
 if (process.platform === 'win32') {

src/plugins/install.js

@@ -13,10 +13,9 @@ const db = require('../database');
 const meta = require('../meta');
 const pubsub = require('../pubsub');
 const { paths } = require('../constants');
+const pkgInstall = require('../cli/package-install');
 
-const supportedPackageManagerList = require('../cli/package-install').supportedPackageManager;
-// load config from src/cli/package-install.js
-const packageManager = supportedPackageManagerList.indexOf(nconf.get('package_manager')) >= 0 ? nconf.get('package_manager') : 'npm';
+const packageManager = pkgInstall.getPackageManager();
 let packageManagerExecutable = packageManager;
 const packageManagerCommands = {
 	yarn: {