From 7e2b1a947436f94c036a51d88686605846f8a136 Mon Sep 17 00:00:00 2001
From: James Garbutt <43081j@users.noreply.github.com>
Date: Mon, 13 May 2024 22:18:38 +0100
Subject: [PATCH] fix: raise a nicer error when non-object errors are matched
 (#294)

When a promise is rejected, we currently incorrectly assume the
rejection reason is an object consumable by check-error (i.e. an `Error`
or similar).

This change basically checks strict equality on the matcher and the
thrown error first (such that `rejectedWith(undefined)` would work). It
then falls back to the original logic only if both the matcher and the
reason are truthy.

Fixes #263
---
 lib/chai-as-promised.js         |  5 ++++-
 test/assert-promise-specific.js | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib/chai-as-promised.js b/lib/chai-as-promised.js
index 0d0cb54..4ffdb2e 100644
--- a/lib/chai-as-promised.js
+++ b/lib/chai-as-promised.js
@@ -215,7 +215,10 @@ export default function (chai, utils) {
             : checkError.compatibleConstructor(reason, errorLike));
 
         const errMsgMatcherCompatible =
-          errMsgMatcher && checkError.compatibleMessage(reason, errMsgMatcher);
+          errMsgMatcher === reason ||
+          (errMsgMatcher &&
+            reason &&
+            checkError.compatibleMessage(reason, errMsgMatcher));
 
         const reasonName = getReasonName(reason);
 
diff --git a/test/assert-promise-specific.js b/test/assert-promise-specific.js
index fc03fc1..7c2f23a 100644
--- a/test/assert-promise-specific.js
+++ b/test/assert-promise-specific.js
@@ -289,5 +289,20 @@ describe('Assert interface:', () => {
         });
       });
     });
+
+    describe('with undefined error', () => {
+      beforeEach(() => {
+        promise = Promise.reject();
+      });
+
+      describe('.isRejected(promise)', () => {
+        shouldPass(() => assert.isRejected(promise));
+        shouldPass(() => assert.isRejected(promise, undefined));
+        shouldFail({
+          op: () => assert.isRejected(promise, 'Error'),
+          message: "to be rejected with an error including 'Error' but got ''"
+        });
+      });
+    });
   });
 });