From 881fe9af609ec2b430a0241f6031067386f4c42b Mon Sep 17 00:00:00 2001
From: jonasroussel <go.jroussel@gmail.com>
Date: Sun, 5 Nov 2023 14:50:46 +0100
Subject: [PATCH] fixing issue with custom headers

---
 CHANGELOG.md     | 4 ++++
 lib/src/jwt.dart | 9 +++++----
 pubspec.yaml     | 2 +-
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b86f7b0..41d8049 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.12.1
+
+- Fixing issue with custom headers (https://github.com/jonasroussel/dart_jsonwebtoken/issues/48)
+
 ## 2.12.0
 
 - **NEW:** tests have been added
diff --git a/lib/src/jwt.dart b/lib/src/jwt.dart
index afc3df8..b23f2e8 100644
--- a/lib/src/jwt.dart
+++ b/lib/src/jwt.dart
@@ -261,9 +261,6 @@ class JWT {
     bool noIssueAt = false,
   }) {
     try {
-      header ??= {};
-      header!.addAll({'alg': algorithm.name, 'typ': 'JWT'});
-
       if (payload is Map<String, dynamic> || payload is Map<dynamic, dynamic>) {
         try {
           payload = Map<String, dynamic>.from(payload);
@@ -287,7 +284,11 @@ class JWT {
         }
       }
 
-      final b64Header = base64Unpadded(jsonBase64.encode(header));
+      final tokenHeader = Map.from(header ?? {});
+      tokenHeader.putIfAbsent('alg', () => algorithm.name);
+      tokenHeader.putIfAbsent('typ', () => 'JWT');
+
+      final b64Header = base64Unpadded(jsonBase64.encode(tokenHeader));
 
       String b64Payload;
       try {
diff --git a/pubspec.yaml b/pubspec.yaml
index 3a26a27..d609838 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: dart_jsonwebtoken
 description: A dart implementation of the famous javascript library 'jsonwebtoken' (JWT).
-version: 2.12.0
+version: 2.12.1
 repository: https://github.com/jonasroussel/dart_jsonwebtoken
 homepage: https://github.com/jonasroussel/dart_jsonwebtoken#readme