From ee0cf8b2a4cb354857adc86a7af285aab317168d Mon Sep 17 00:00:00 2001
From: Alexandra Tudor <alexandra.tudor@hermes.com>
Date: Wed, 29 May 2024 14:20:09 +0200
Subject: [PATCH] Feature - optionally include Error.cause property

---
 lib/winston/logger.js            |  1 +
 test/unit/winston/logger.test.js | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/lib/winston/logger.js b/lib/winston/logger.js
index 5f8758c89..adc2ee589 100644
--- a/lib/winston/logger.js
+++ b/lib/winston/logger.js
@@ -248,6 +248,7 @@ class Logger extends Transform {
 
         if (meta.message) info.message = `${info.message} ${meta.message}`;
         if (meta.stack) info.stack = meta.stack;
+        if (meta.cause) info.cause = meta.cause;
 
         this.write(info);
         return this;
diff --git a/test/unit/winston/logger.test.js b/test/unit/winston/logger.test.js
index 83504f594..48ff644eb 100755
--- a/test/unit/winston/logger.test.js
+++ b/test/unit/winston/logger.test.js
@@ -1016,6 +1016,19 @@ describe('Logger Instance', function () {
 
         logger.log('info', '%d%% such %s %j', 100, 'wow', {much: 'javascript'}, {thisIsMeta: true});
       });
+
+      it(`.log(level, new Error()) creates info with error cause`, function (done) {
+        const errCause = new Error("error cause");
+        const err = new Error('test', { cause: errCause });
+        const logger = helpers.createLogger(function (info) {
+          assume(info).instanceOf(Error);
+          assume(info).equals(err);
+          assume(info.cause).equals(errCause)
+          done();
+        });
+
+        logger.log('info', err);
+      });
     });
   });
 });