From b8583d4db48aa2195667ae161973c54b81160f5d Mon Sep 17 00:00:00 2001
From: Romain Hamel <rom.hml@gmail.com>
Date: Fri, 8 Mar 2024 08:08:47 +0100
Subject: [PATCH] fix: stringify key identifier starting with number literal
 (#86)

---
 src/utils.ts       | 2 +-
 test/index.test.ts | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/utils.ts b/src/utils.ts
index 19f0977..5f63cd7 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -15,7 +15,7 @@ export function wrapInDelimiters(
   );
 }
 
-const VALID_IDENTIFIER_RE = /^[$_]?\w*$/;
+const VALID_IDENTIFIER_RE = /^[$_]?([A-Z_a-z]\w*|\d)$/;
 
 export function genObjectKey(key: string) {
   return VALID_IDENTIFIER_RE.test(key) ? key : genString(key);
diff --git a/test/index.test.ts b/test/index.test.ts
index 65b00c2..0903f09 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -118,6 +118,8 @@ const genObjectFromRawTests = [
       1: "undefined",
       2: true,
       3: "true",
+      "2xs": true,
+      xs2: true,
       "obj 1": '{ literal: () => "test" }',
       "obj 2": { nested: { foo: '"bar"' } },
       arr: ["1", "2", "3"],
@@ -130,6 +132,8 @@ const genObjectFromRawTests = [
       "  a: null,",
       "  b: null,",
       "  c: undefined,",
+      '  "2xs": true,',
+      "  xs2: true,",
       '  "obj 1": { literal: () => "test" },',
       '  "obj 2": {',
       "    nested: {",