From cf7710faa17bfce8cdd03d4bb92febc1f196cf33 Mon Sep 17 00:00:00 2001
From: Michael Wang <michael19920327@gmail.com>
Date: Wed, 25 Sep 2024 17:30:01 +0800
Subject: [PATCH] fix: should get undecoded flash message when it is not been
 base64 encode in session

---
 lib/flash.js       | 12 ++++++++++--
 test/flash-test.js | 23 ++++++++++++++++++-----
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/lib/flash.js b/lib/flash.js
index 254b4d9..0bd2fcb 100644
--- a/lib/flash.js
+++ b/lib/flash.js
@@ -9,7 +9,11 @@ function base64Encode(str) {
 }
 
 function base64Decode(str) {
-  return Buffer.from(str, 'base64').toString();
+  return Buffer.from(str, 'base64').toString('utf-8');
+}
+
+function isBase64(str) {
+  return Buffer.from(str, 'base64').toString('base64') === str;
 }
 
 /**
@@ -87,7 +91,11 @@ function _flash(type, msg) {
     delete msgs[type];
     // decode msg from base64
     if (Array.isArray(arr)) {
-      return arr.map(base64Decode);
+      return arr.map((val) => {
+        // if it is not base64, return it as is
+        if (!isBase64(val)) return val;
+        return base64Decode(val);
+      });
     }
     return [];
   } else {
diff --git a/test/flash-test.js b/test/flash-test.js
index 2807a1f..1e8ecf5 100644
--- a/test/flash-test.js
+++ b/test/flash-test.js
@@ -50,14 +50,27 @@ vows.describe('flash').addBatch({
         assert.equal(msgs[0], 'Something went wrong');
         assert.lengthOf(Object.keys(req.session.flash), 0);
       },
-      'should set/get flash unicode message' : function(err, req, res) {
-        const count = req.flash('error', 'a Ā 𐀀 文 🦄');
-        assert.equal(count, 1);
+      'should be encoded to base64 in session' : function(err, req, res) {
+        req.flash('error', 'Something went wrong');
+        assert.equal(req.session.flash.error[0], 'U29tZXRoaW5nIHdlbnQgd3Jvbmc=');
+        const msgs = req.flash('error');
+        assert.equal(msgs[0], 'Something went wrong');
+      },
+      'should set/get unicode flash message' : function(err, req, res) {
+        req.flash('error', 'a Ā 𐀀 文 🦄');
         assert.equal(req.session.flash.error[0], 'YSDEgCDwkICAIOaWhyDwn6aE');
         const msgs = req.flash('error');
-        assert.lengthOf(msgs, 1);
         assert.equal(msgs[0], 'a Ā 𐀀 文 🦄');
-        assert.lengthOf(Object.keys(req.session.flash), 0);
+      },
+      'should get undecoded flash message when it is not been base64 encode in session' : function(err, req, res) {
+        req.flash('error', 'Something went wrong');
+        req.session.flash.error.push('Something went wrong');
+        assert.equal(req.session.flash.error[0], 'U29tZXRoaW5nIHdlbnQgd3Jvbmc=');
+        assert.equal(req.session.flash.error[1], 'Something went wrong');
+        console.log(req.session.flash.error);
+        const msgs = req.flash('error');
+        assert.equal(msgs[0], 'Something went wrong');
+        assert.equal(msgs[1], 'Something went wrong');
       },
       'should set multiple flash messages' : function(err, req, res) {
         req.flash('info', 'Welcome');