From 121c37f100b97f1d2c3f68c436f92bd7df4a120a Mon Sep 17 00:00:00 2001
From: Onsi Fakhouri <onsijoe@gmail.com>
Date: Wed, 17 Jan 2024 13:57:16 -0700
Subject: [PATCH] Async assertions include context cancellation cause if
 present

---
 internal/async_assertion.go      |  7 ++++++-
 internal/async_assertion_test.go | 18 +++++++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/internal/async_assertion.go b/internal/async_assertion.go
index 1188b0bce..cde9e2ec8 100644
--- a/internal/async_assertion.go
+++ b/internal/async_assertion.go
@@ -553,7 +553,12 @@ func (assertion *AsyncAssertion) match(matcher types.GomegaMatcher, desiredMatch
 				lock.Unlock()
 			}
 		case <-contextDone:
-			fail("Context was cancelled")
+			err := context.Cause(assertion.ctx)
+			if err != nil && err != context.Canceled {
+				fail(fmt.Sprintf("Context was cancelled (cause: %s)", err))
+			} else {
+				fail("Context was cancelled")
+			}
 			return false
 		case <-timeout:
 			if assertion.asyncType == AsyncAssertionTypeEventually {
diff --git a/internal/async_assertion_test.go b/internal/async_assertion_test.go
index accdfe55c..c966dead2 100644
--- a/internal/async_assertion_test.go
+++ b/internal/async_assertion_test.go
@@ -1,6 +1,7 @@
 package internal_test
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"reflect"
@@ -10,7 +11,6 @@ import (
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
-	"golang.org/x/net/context"
 )
 
 type quickMatcher struct {
@@ -275,6 +275,22 @@ var _ = Describe("Asynchronous Assertions", func() {
 					Ω(ig.FailureMessage).Should(ContainSubstring("Context was cancelled after"))
 					Ω(ig.FailureMessage).Should(ContainSubstring("There is no failure as the matcher passed to Consistently has not yet failed"))
 				})
+
+				It("includes the cancel cause if provided", func() {
+					ctx, cancel := context.WithCancelCause(context.Background())
+					counter := 0
+					ig.G.Eventually(func() string {
+						counter++
+						if counter == 2 {
+							cancel(fmt.Errorf("kaboom"))
+						} else if counter == 10 {
+							return MATCH
+						}
+						return NO_MATCH
+					}, time.Hour, ctx).Should(SpecMatch())
+					Ω(ig.FailureMessage).Should(ContainSubstring("Context was cancelled (cause: kaboom) after"))
+					Ω(ig.FailureMessage).Should(ContainSubstring("positive: no match"))
+				})
 			})
 
 			Context("when the passed-in context is a Ginkgo SpecContext that can take a progress reporter attachment", func() {