From 38e1958be82a258e6f954ea99428f8d830f6cb89 Mon Sep 17 00:00:00 2001
From: Pelle Wessman <pelle@kodfabrik.se>
Date: Wed, 2 Mar 2022 12:28:15 +0100
Subject: [PATCH] Adapt stackWithCauses() to node.js output

Fixes #22
Related to: https://github.com/staltz/clarify-error/issues/1 and https://github.com/nodejs/node/pull/41002
---
 index.js           | 10 ++++++++--
 test/stack.spec.js | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 4347966..a055500 100644
--- a/index.js
+++ b/index.js
@@ -103,11 +103,17 @@ const _stackWithCauses = (err, seen) => {
 
   const cause = getErrorCause(err);
 
-  // TODO: Follow up in https://github.com/nodejs/node/issues/38725#issuecomment-920309092 on how to log stuff
-
   if (cause) {
     seen.add(err);
     return (stack + '\ncaused by: ' + _stackWithCauses(cause, seen));
+  } else if (
+    // @ts-ignore
+    err.cause
+  ) {
+    return (stack + '\ncaused by: ' + JSON.stringify(
+      // @ts-ignore
+      err.cause
+    ));
   } else {
     return stack;
   }
diff --git a/test/stack.spec.js b/test/stack.spec.js
index acbf6b3..e1c1f1c 100644
--- a/test/stack.spec.js
+++ b/test/stack.spec.js
@@ -92,4 +92,37 @@ describe('stackWithCauses()', () => {
     const result = stackWithCauses(err);
     result.should.equal('xyz789\ncaused by: abc123\ncaused by: xyz789\ncauses have become circular...');
   });
+
+  it('should append non-Error string causes to the end of the cause trail', () => {
+    const cause = 'string cause';
+
+    const err = new ErrorWithCause('foo', { cause });
+    err.stack = 'xyz789';
+
+    const result = stackWithCauses(err);
+    should.exist(result);
+    result.should.equal('xyz789\ncaused by: "string cause"');
+  });
+
+  it('should append non-Error number causes to the end of the cause trail', () => {
+    const cause = 123;
+
+    const err = new ErrorWithCause('foo', { cause });
+    err.stack = 'xyz789';
+
+    const result = stackWithCauses(err);
+    should.exist(result);
+    result.should.equal('xyz789\ncaused by: 123');
+  });
+
+  it('should append non-Error object causes to the end of the cause trail', () => {
+    const cause = { name: 'TypeError', message: 'foo' };
+
+    const err = new ErrorWithCause('foo', { cause });
+    err.stack = 'xyz789';
+
+    const result = stackWithCauses(err);
+    should.exist(result);
+    result.should.equal('xyz789\ncaused by: {"name":"TypeError","message":"foo"}');
+  });
 });