From f5d47ef13739162fa2a5c0ba1e471e9328ad248a Mon Sep 17 00:00:00 2001
From: overlookmotel <theoverlookmotel@gmail.com>
Date: Fri, 24 Nov 2023 20:25:55 +0000
Subject: [PATCH] WIP 2

---
 lib/instrument/blocks.js         |  4 +---
 lib/instrument/visitors/eval.js  | 17 +++--------------
 lib/instrument/visitors/super.js | 15 ---------------
 lib/serialize/blocks.js          |  5 ++---
 4 files changed, 6 insertions(+), 35 deletions(-)

diff --git a/lib/instrument/blocks.js b/lib/instrument/blocks.js
index c688f9e1..40df4e3e 100644
--- a/lib/instrument/blocks.js
+++ b/lib/instrument/blocks.js
@@ -147,9 +147,7 @@ function createBindingWithoutNameCheck(block, varName, props) {
  * @returns {Object} - Binding object
  */
 function createThisBinding(block) {
-	// `isFrozenName: true` because it cannot be renamed within function in which it's created.
-	// If `this` has to be substituted for a temp var for transpiled `super()`,
-	// `isFrozenName` will be set to false.
+	// `isFrozenName: true` because it cannot be renamed within function in which it's created
 	return createBindingWithoutNameCheck(
 		// eslint-disable-next-line no-use-before-define
 		block, 'this', {varNode: thisNode, isConst: true, isFrozenName: true}
diff --git a/lib/instrument/visitors/eval.js b/lib/instrument/visitors/eval.js
index e28bd7ae..03df9aba 100644
--- a/lib/instrument/visitors/eval.js
+++ b/lib/instrument/visitors/eval.js
@@ -13,13 +13,13 @@ const t = require('@babel/types');
 
 // Imports
 const {
-		activateSuperBinding, getParentFullFunction, createInternalVarForThis, createExternalVarForThis,
+		activateSuperBinding, getParentFullFunction, createExternalVarForThis,
 		setSuperIsProtoOnFunctions
 	} = require('./super.js'),
 	{getOrCreateExternalVar, activateBlock, activateBinding} = require('../blocks.js'),
 	{createTempVarNode} = require('../internalVars.js'),
 	{copyLocAndComments} = require('../utils.js'),
-	{isReservedWord, getProp} = require('../../shared/functions.js');
+	{isReservedWord} = require('../../shared/functions.js');
 
 // Exports
 
@@ -141,13 +141,11 @@ function instrumentEvalCall(callNode, block, fn, isStrict, canUseSuper, superIsP
 			// Freeze binding to prevent var being renamed when used internally in a function.
 			// All vars in scope need to be frozen, even if not accessible to `eval()`
 			// because if they're renamed, they would become accessible to `eval()` when they weren't before.
-			// `this` should not be frozen internally, as it can be replaced with a variable
-			// in a class constructor when `super()` is transpiled.
 			// For `super` and `new.target`, the var name can't actually be frozen, but flagged here
 			// as frozen anyway, to indicate that replacement var name should be prefixed with `_`.
 			// Frozen `new.target` is not currently supported.
 			// https://github.com/overlookmotel/livepack/issues/448
-			if (varName !== 'this' && !binding.isFrozenName) {
+			if (!binding.isFrozenName) {
 				binding.isFrozenName = true;
 				binding.trails.length = 0;
 			}
@@ -286,15 +284,6 @@ function activateSuperIfIsUsable(fn, state) {
 				if (fullFnType === 'FunctionDeclaration' || fullFnType === 'FunctionExpression') return false;
 			}
 			createExternalVarForThis(fn, state);
-		} else if (fnType === 'ClassDeclaration' || fnType === 'ClassExpression') {
-			const {trail} = state;
-			if (trail.length > 6) {
-				const maybeConstructorNode = getProp(fn.node, trail, 3);
-				if (maybeConstructorNode.type === 'ClassMethod' && maybeConstructorNode.kind === 'constructor') {
-					// In class constructor - need internal var for `this` as `eval()` code might include `super()`
-					createInternalVarForThis(fn, state);
-				}
-			}
 		}
 
 		setSuperIsProtoOnFunctions(superBlock, fn, state);
diff --git a/lib/instrument/visitors/super.js b/lib/instrument/visitors/super.js
index 32664396..032623b9 100644
--- a/lib/instrument/visitors/super.js
+++ b/lib/instrument/visitors/super.js
@@ -10,7 +10,6 @@ module.exports = {
 	Super,
 	recordSuper,
 	activateSuperBinding,
-	createInternalVarForThis,
 	createExternalVarForThis,
 	setSuperIsProtoOnFunctions,
 	getSuperVarNode,
@@ -95,20 +94,6 @@ function activateSuperBinding(superBlock, state) {
 	return binding;
 }
 
-/**
- * Create internal var for `this` on function.
- * @param {Object} fn - Function object
- * @param {Object} state - State object
- * @returns {undefined}
- */
-function createInternalVarForThis(fn, state) {
-	const binding = state.currentThisBlock.bindings.this;
-	if (binding.isFrozenName) {
-		binding.isFrozenName = false;
-		fn.bindings.push(binding);
-	}
-}
-
 /**
  * Create external var for `this` on function.
  * @param {Object} fn - Function object
diff --git a/lib/serialize/blocks.js b/lib/serialize/blocks.js
index 4ea9fe97..e525c682 100644
--- a/lib/serialize/blocks.js
+++ b/lib/serialize/blocks.js
@@ -511,9 +511,8 @@ module.exports = {
 			// Function names and vars which are frozen by `eval()` aren't included in `internalVars`.
 			const transformVarName = this.createVarNameTransform(fnReservedVarNames);
 			for (const varName in internalVars) {
-				// `this` is only included in `internalVars` if it's the faux `this` created for transpiled
-				// `super()`. If function contains `eval()`, make sure it's prefixed with "_".
-				const newName = transformVarName(varName, fnContainsEval && varName === 'this');
+				// NB: Frozen vars are not included in `internalVars`
+				const newName = transformVarName(varName, false);
 				if (newName !== varName) {
 					for (const varNode of internalVars[varName]) {
 						varNode.name = newName;