[llvm] [Offload] Make `ASSERT_ERROR` output more readable (PR #157653)

[Ross Brunton via llvm-commits]

https://github.com/RossBrunton created https://github.com/llvm/llvm-project/pull/157653

None

>From eaa31d7210d58c49120ac9092e4abb4a8648b27d Mon Sep 17 00:00:00 2001
From: Ross Brunton <ross at codeplay.com>
Date: Tue, 9 Sep 2025 12:48:09 +0100
Subject: [PATCH] [Offload] Make `ASSERT_ERROR` output more readable

---
 offload/unittests/OffloadAPI/common/Fixtures.hpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/offload/unittests/OffloadAPI/common/Fixtures.hpp b/offload/unittests/OffloadAPI/common/Fixtures.hpp
index c5a35faba7a27..6f9961e2c6d58 100644
--- a/offload/unittests/OffloadAPI/common/Fixtures.hpp
+++ b/offload/unittests/OffloadAPI/common/Fixtures.hpp
@@ -40,12 +40,16 @@
   } while (0)
 #endif
 
-// TODO: rework this so the EXPECTED/ACTUAL results are readable
 #ifndef ASSERT_ERROR
 #define ASSERT_ERROR(EXPECTED, ACTUAL)                                         \
   do {                                                                         \
     ol_result_t Res = ACTUAL;                                                  \
-    ASSERT_TRUE(Res && (Res->Code == EXPECTED));                               \
+    if (!Res)                                                                  \
+      GTEST_FAIL() << #ACTUAL " succeeded when we expected it to fail";        \
+    if (Res->Code != EXPECTED)                                                 \
+      GTEST_FAIL() << #ACTUAL " was expected to return "                       \
+                   << #EXPECTED " but instead returned " << Res->Code << ": "  \
+                   << Res->Details;                                            \
   } while (0)
 #endif