From d35881fb27a0bb63133c38c5bdf38955b992c50b Mon Sep 17 00:00:00 2001
From: overlookmotel <theoverlookmotel@gmail.com>
Date: Sat, 23 Dec 2023 02:52:51 +0000
Subject: [PATCH] Capture `module` objects when function declaration called
 `module` at top level [fix]

Fixes #566.
---
 lib/init/index.js        |  9 +++------
 lib/init/module.js       | 12 +++++++++++-
 lib/instrument/modify.js |  3 +--
 test/commonjs.test.js    | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 47 insertions(+), 9 deletions(-)

diff --git a/lib/init/index.js b/lib/init/index.js
index 49e37af8..db21c89d 100644
--- a/lib/init/index.js
+++ b/lib/init/index.js
@@ -10,8 +10,7 @@
 // Imports
 const createTracker = require('./tracker.js'),
 	getScopeId = require('./getScopeId.js'),
-	internal = require('../shared/internal.js'),
-	{COMMON_JS_MODULE} = require('../shared/constants.js');
+	internal = require('../shared/internal.js');
 
 // Exports
 
@@ -26,15 +25,13 @@ const {globals, functions: specialFunctions} = internal;
  * Additional methods which are universal are attached to `livepack_getScopeId`.
  *
  * @param {string} filename - File path
- * @param {Object} module - `module` object from file
  * @param {Function} require - `require` function from file
  * @param {number} nextBlockId - Next block ID
  * @param {number} prefixNum - Internal vars prefix num
  * @returns {Array<Function>} - Array containing tracker and `getScopeId` functions
  */
-module.exports = (filename, module, require, nextBlockId, prefixNum) => {
-	// Record `module` + `require`
-	globals.set(module, {type: COMMON_JS_MODULE, parent: null, key: 'module'});
+module.exports = (filename, require, nextBlockId, prefixNum) => {
+	// Record `require`
 	specialFunctions.set(require, {type: 'require', path: filename});
 	specialFunctions.set(require.resolve, {type: 'require', path: filename});
 	specialFunctions.set(require.resolve.paths, {type: 'require', path: filename});
diff --git a/lib/init/module.js b/lib/init/module.js
index fb485ebb..9f6d68d6 100644
--- a/lib/init/module.js
+++ b/lib/init/module.js
@@ -11,7 +11,8 @@ const Module = require('module');
 // Imports
 const {catalogBuiltInModule} = require('./globals.js'),
 	{usingInternalModuleCache} = require('../shared/moduleCache.js'),
-	{globals, functions: specialFunctions} = require('../shared/internal.js');
+	{globals, functions: specialFunctions} = require('../shared/internal.js'),
+	{COMMON_JS_MODULE} = require('../shared/constants.js');
 
 // Exports
 
@@ -36,6 +37,15 @@ module.exports = function patchModule() {
 		return exports;
 	};
 	Module.prototype.require.main = requireOriginal.main;
+
+	// Patch `Module.prototype.load` to record `module` object
+	const loadOriginal = Module.prototype.load;
+	Module.prototype.load = function(filename) {
+		if (!usingInternalModuleCache()) {
+			globals.set(this, {type: COMMON_JS_MODULE, parent: null, key: 'module'});
+		}
+		loadOriginal.call(this, filename);
+	};
 };
 
 /**
diff --git a/lib/instrument/modify.js b/lib/instrument/modify.js
index 1aa81acb..e4adb441 100644
--- a/lib/instrument/modify.js
+++ b/lib/instrument/modify.js
@@ -233,7 +233,7 @@ function insertImportStatement(programNode, state) {
 	// ```
 	// const [livepack_tracker, livepack_getScopeId]
 	//   = require('/path/to/app/node_modules/livepack/lib/init/index.js')
-	//     ('/path/to/app/file.js', module, require, 100, 0);
+	//     ('/path/to/app/file.js', require, 100, 0);
 	// ```
 	const statementNode = t.variableDeclaration(
 		'const', [
@@ -243,7 +243,6 @@ function insertImportStatement(programNode, state) {
 					t.callExpression(t.identifier('require'), [t.stringLiteral(INIT_PATH)]),
 					[
 						t.stringLiteral(state.filename),
-						t.identifier('module'),
 						t.identifier('require'),
 						t.numericLiteral(state.nextBlockId),
 						t.numericLiteral(state.internalVarsPrefixNum)
diff --git a/test/commonjs.test.js b/test/commonjs.test.js
index d404a98a..cd6b97b3 100644
--- a/test/commonjs.test.js
+++ b/test/commonjs.test.js
@@ -69,6 +69,38 @@ describe('`module`', () => {
 			expect(fn()).toBe(123);
 		}
 	});
+
+	itSerializes('var overriden by function declaration and module object exported', {
+		in: `
+			'use strict';
+			function module() { return 123; }
+			// arguments[2] is module object
+			arguments[2].exports = arguments[2];
+		`,
+		out: '(()=>{const a={};a.exports=a;return a})()',
+		validate(mod, {isOutput}) {
+			expect(mod).toBeObject();
+			if (isOutput) expect(mod).toHaveOwnPropertyNames(['exports']);
+			expect(mod.exports).toBe(mod);
+		}
+	});
+
+	itSerializes('var overriden by function declaration and function exported', {
+		in: `
+			'use strict';
+			function module() { return 123; }
+			exports.x = module;
+		`,
+		out: '{x:function module(){return 123}}',
+		validate(obj) {
+			expect(obj).toBeObject();
+			expect(obj).toHaveOwnPropertyNames(['x']);
+			const fn = obj.x;
+			expect(fn).toBeFunction();
+			expect(fn.name).toBe('module');
+			expect(fn()).toBe(123);
+		}
+	});
 });
 
 describe('`exports`', () => {