From f9e83c000f5a6f43c6223202adc205de591c289f Mon Sep 17 00:00:00 2001
From: JonLuca DeCaro <jonluca.decaro@gmail.com>
Date: Tue, 5 Mar 2024 18:40:23 -0800
Subject: [PATCH] fix(parsing): allow invalid decodeUriComponent parsing to
 occur #296

---
 lib/pointer.ts                  | 10 +++++++++-
 test/specs/pointer/null.spec.ts |  8 ++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 test/specs/pointer/null.spec.ts

diff --git a/lib/pointer.ts b/lib/pointer.ts
index 35aeedc0..5a32fa7d 100644
--- a/lib/pointer.ts
+++ b/lib/pointer.ts
@@ -8,6 +8,14 @@ const tildes = /~/g;
 const escapedSlash = /~1/g;
 const escapedTilde = /~0/g;
 
+const safeDecodeURIComponent = (encodedURIComponent: string): string => {
+  try {
+    return decodeURIComponent(encodedURIComponent);
+  } catch {
+    return encodedURIComponent;
+  }
+};
+
 /**
  * This class represents a single JSON pointer and its resolved value.
  *
@@ -181,7 +189,7 @@ class Pointer {
 
     // Decode each part, according to RFC 6901
     for (let i = 0; i < pointer.length; i++) {
-      pointer[i] = decodeURIComponent(pointer[i].replace(escapedSlash, "/").replace(escapedTilde, "~"));
+      pointer[i] = safeDecodeURIComponent(pointer[i].replace(escapedSlash, "/").replace(escapedTilde, "~"));
     }
 
     if (pointer[0] !== "") {
diff --git a/test/specs/pointer/null.spec.ts b/test/specs/pointer/null.spec.ts
new file mode 100644
index 00000000..d8d912ed
--- /dev/null
+++ b/test/specs/pointer/null.spec.ts
@@ -0,0 +1,8 @@
+import { describe, it } from "vitest";
+import Pointer from "../../../lib/pointer";
+
+describe("Pointers", () => {
+  it("should parse successfully", async () => {
+    Pointer.parse("#/c%d");
+  });
+});