Fix identifier checking

lxsmnsyc · Mar 17, 2023 · bd157e3 · bd157e3
1 parent 59b6756
commit bd157e3
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Showing 2 changed files with 15 additions and 4 deletions.
diff --git a/packages/seroval/src/tree/serialize.ts b/packages/seroval/src/tree/serialize.ts
@@ -7,6 +7,7 @@ import {
   markRef,
 } from '../context';
 import quote from '../quote';
+import { isValidIdentifier } from './shared';
 import { SYMBOL_STRING } from './symbols';
 import {
   SerovalAggregateErrorNode,
@@ -191,8 +192,6 @@ function isReferenceInStack(
   return node.t === SerovalNodeType.Reference && ctx.stack.includes(node.i);
 }
 
-const IDENTIFIER_CHECK = /^([$A-Z_][0-9A-Z_$]*)$/i;
-
 function serializeNodeList(
   ctx: SerializationContext,
   node: SerovalArrayNode | SerovalIterableNode | SerovalAggregateErrorNode,
@@ -262,7 +261,7 @@ function serializeProperties(
     check = Number(key);
     // Test if key is a valid number or JS identifier
     // so that we don't have to serialize the key and wrap with brackets
-    isIdentifier = check >= 0 || IDENTIFIER_CHECK.test(key);
+    isIdentifier = check >= 0 || isValidIdentifier(key);
     if (isReferenceInStack(ctx, val)) {
       refParam = getRefParam(ctx, val.i);
       if (isIdentifier && Number.isNaN(check)) {
@@ -320,7 +319,7 @@ function serializeAssignments(
     ctx.assignments = mainAssignments;
     // Test if key is a valid number or JS identifier
     // so that we don't have to serialize the key and wrap with brackets
-    isIdentifier = check >= 0 || IDENTIFIER_CHECK.test(key);
+    isIdentifier = check >= 0 || isValidIdentifier(key);
     if (isIdentifier && Number.isNaN(check)) {
       createObjectAssign(ctx, sourceID, key, refParam);
     } else {

diff --git a/packages/seroval/src/tree/shared.ts b/packages/seroval/src/tree/shared.ts
@@ -131,3 +131,15 @@ export function getTypedArrayConstructor(name: string) {
       throw new Error(`Unknown TypedArray "${name}"`);
   }
 }
+
+const IDENTIFIER_CHECK = /^[$A-Z_][0-9A-Z_$]*$/i;
+
+export function isValidIdentifier(name: string) {
+  const char = name[0];
+  return (
+    char === '$'
+    || char === '_'
+    || (char >= 'A' && char <= 'Z')
+    || (char >= 'a' && char <= 'z')
+  ) && IDENTIFIER_CHECK.test(name);
+}