Fix edge cases (#68)

* Add optional chaining where script broke in some cases

* Verify arguments are in the form of an array

* Prevent resolving builtin member expression calls where the object is 'this' or the property is a constructor.

* 1.6.4

package.json

@@ -1,6 +1,6 @@
 {
   "name": "restringer",
-  "version": "1.6.3",
+  "version": "1.6.4",
   "description": "Deobfuscate Javascript with emphasis on reconstructing strings",
   "main": "index.js",
   "bin": {

src/modules/safe/replaceCallExpressionsWithUnwrappedIdentifier.js

@@ -27,7 +27,7 @@ function replaceCallExpressionsWithUnwrappedIdentifier(arb, candidateFilter = ()
 				}
 			} else if (declBody.type === 'BlockStatement' && declBody.body.length === 1 && declBody.body[0].type === 'ReturnStatement') {
 				const arg = declBody.body[0].argument;
-				if (arg.type === 'Identifier' || (arg.type === 'CallExpression' && !arg.arguments.length)) {
+				if (arg.type === 'Identifier' || (arg.type === 'CallExpression' && !arg.arguments?.length)) {
 					arb.markNode(c, arg);
 				}
 			}

src/modules/safe/resolveProxyCalls.js

@@ -21,7 +21,7 @@ function resolveProxyCalls(arb, candidateFilter = () => true) {
 		n.body?.body?.length === 1 &&
 		n.body.body[0].type === 'ReturnStatement' &&
 		n.body.body[0].argument?.type === 'CallExpression' &&
-		n.body.body[0].argument.arguments.length === n.params.length &&
+		n.body.body[0].argument.arguments?.length === n.params?.length &&
 		n.body.body[0].argument.callee.type === 'Identifier' &&
 		candidateFilter(n));
 

src/modules/safe/simplifyCalls.js

@@ -16,10 +16,11 @@ function simplifyCalls(arb, candidateFilter = () => true) {
 		candidateFilter(n));
 
 	for (const c of candidates) {
+		const args = (c.callee.property?.name || c.callee.property?.value) === 'apply' ? c.arguments[1].elements : c.arguments.slice(1);
 		arb.markNode(c,  {
 			type: 'CallExpression',
 			callee: c.callee.object,
-			arguments: (c.callee.property?.name || c.callee.property?.value) === 'apply' ? c.arguments[1].elements : c.arguments.slice(1),
+			arguments: Array.isArray(args) ? args : (args ? [args] : []),
 		});
 	}
 	return arb;

src/modules/unsafe/resolveBuiltinCalls.js

@@ -39,6 +39,8 @@ function resolveBuiltinCalls(arb, candidateFilter = () => true) {
 		try {
 			const callee = c.callee;
 			if (callee?.declNode || callee?.object?.declNode) continue;
+			if ((callee?.object?.type || callee.type ) === 'ThisExpression' ||
+				(callee?.property?.name || callee?.property?.value) === 'constructor') continue;
 			const safeImplementation = safeImplementations[callee.name];
 			if (safeImplementation) {
 				const args = c.arguments.map(a => a.value);