From 20420ae54ace38128e2b9d9cfeb53c8f979621cf Mon Sep 17 00:00:00 2001
From: Eduard Marbach <mail@eduard-marbach.de>
Date: Sun, 27 Oct 2019 12:33:49 +0100
Subject: [PATCH] feat: Add PNPM support

---
 lib/resolve.js | 43 +++++++++++++++++++++++++++------
 test/index.js  | 65 ++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 89 insertions(+), 19 deletions(-)

diff --git a/lib/resolve.js b/lib/resolve.js
index 2e9b8d5..8ba6237 100644
--- a/lib/resolve.js
+++ b/lib/resolve.js
@@ -23,6 +23,30 @@ var requireFunction = ("function" === typeof __webpack_require__ || "function" =
 	? __non_webpack_require__
 	: require;
 
+const isInstalledWithPNPM = function(resolved) {
+	const pnpmDir = sep + '.pnpm';
+
+	for (const globalPath of globalPaths) {
+		if (-1 !== globalPath.indexOf(pnpmDir) && -1 !== resolved.indexOf(pnpmDir)) {
+			return true;
+		}
+	}
+	return false;
+}
+
+const getFirstPartFromNodeModules = function(resolved) {
+	const nodeModulesDir = sep + 'node_modules';
+
+	if (-1 !== resolved.indexOf(nodeModulesDir)) {
+		const parts = resolved.split(nodeModulesDir);
+		if (parts.length) {
+			return parts[0];
+		}
+	}
+
+	return null;
+}
+
 // Resolver
 module.exports = function resolve(dirname) {
 	// Check for environmental variable
@@ -55,6 +79,16 @@ module.exports = function resolve(dirname) {
 	var alternateMethod = false;
 	var appRootPath = null;
 
+	// Check if the globalPaths contain some folders with '.pnpm' in the path
+	// If yes this means it is most likely installed with pnpm
+	if (isInstalledWithPNPM(resolved)) {
+		appRootPath = getFirstPartFromNodeModules(resolved);
+
+		if (appRootPath) {
+			return appRootPath;
+		}
+	}
+
 	// Make sure that we're not loaded from a global include path
 	// Eg. $HOME/.node_modules
 	//     $HOME/.node_libraries
@@ -67,13 +101,8 @@ module.exports = function resolve(dirname) {
 
 	// If the app-root-path library isn't loaded globally,
 	// and node_modules exists in the path, just split __dirname
-	var nodeModulesDir = sep + 'node_modules';
-	if (!alternateMethod && -1 !== resolved.indexOf(nodeModulesDir)) {
-		var parts = resolved.split(nodeModulesDir);
-		if (parts.length) {
-			appRootPath = parts[0];
-			parts = null;
-		}
+	if (!alternateMethod) {
+		appRootPath = getFirstPartFromNodeModules(resolved);
 	}
 
 	// If the above didn't work, or this module is loaded globally, then
diff --git a/test/index.js b/test/index.js
index f72ec58..d5e03a2 100644
--- a/test/index.js
+++ b/test/index.js
@@ -4,9 +4,16 @@ var path = require('path');
 var assert = require('assert');
 var mockery = require('mockery');
 
+function globalPathsContainPnpm() {
+	return undefined !== require('module').globalPaths.find(function(e) {
+		return e.indexOf('.pnpm') !== -1
+	});
+}
+
 describe('The path resolution method', function() {
 	var resolve = require('../lib/resolve.js');
 	var originalReqMainFilename = require.main.filename;
+	const isPnpm = globalPathsContainPnpm();
 
 	// Make sure env variable isn't set for tests
 	if (process.env.APP_ROOT_PATH) {
@@ -21,14 +28,53 @@ describe('The path resolution method', function() {
 		require.main.filename = originalReqMainFilename;
 	});
 
-	// Check global paths
-	it('should use require.main.filename if the path is in the globalPaths array', function() {
-		var expected = path.dirname(require.main.filename);
-		require('module').globalPaths.forEach(function(globalPath) {
-			var testPath = globalPath + path.sep + 'node-app-root-path';
-			assert.equal(resolve(testPath), expected);
+	if (isPnpm) {
+		it('should use require.main.filename if the path is in the globalPaths array (PNPM)', function() {
+			var expected = path.dirname(require.main.filename);
+			var root = path.resolve(__dirname, '..');
+
+			require('module').globalPaths.forEach(function(globalPath) {
+				var testPath = globalPath + path.sep + 'node-app-root-path';
+				
+				if (-1 !== testPath.indexOf('.pnpm')) {
+					assert.equal(resolve(testPath), root);
+				} else {
+					assert.equal(resolve(testPath), expected);
+				}
+			});
+		});
+
+		// Check pnpm
+		it('should use String.split() if installed with pnpm', function() {
+			var cases = [
+				'/var/www/node_modules/.pnpm/node_modules/node-app-root-path',
+				'/var/www/node_modules/.pnpm/custom_registry/node-app-root-path',
+			];
+			var expected = '/var/www';
+
+			cases.forEach(function(testPath) {
+				assert.equal(resolve(testPath), expected);
+			});
 		});
-	});
+
+		// Check root path
+		it('should still use String.split() in the root directory (PNPM)', function() {
+			assert.equal(resolve('/node_modules'), path.dirname(require.main.filename));
+		});
+	} else {
+		it('should use require.main.filename if the path is in the globalPaths array', function() {
+			var expected = path.dirname(require.main.filename);
+			require('module').globalPaths.forEach(function(globalPath) {
+				var testPath = globalPath + path.sep + 'node-app-root-path';
+				assert.equal(resolve(testPath), expected);
+			});
+		});
+
+		// Check root path
+		it('should still use String.split() in the root directory', function() {
+			assert.equal(resolve('/node_modules'), '');
+		});
+	}
 
 	// Check bin/ dir in global path
 	it('should correctly handle the global bin/ edge case', function() {
@@ -54,11 +100,6 @@ describe('The path resolution method', function() {
 		});
 	});
 
-	// Check root path
-	it('should still use String.split() in the root directory', function() {
-		assert.equal(resolve('/node_modules'), '');
-	});
-
 	// Check unexpected path
 	it('should use require.main.filename on unexpected input', function() {
 		var cases = [