fix(assert): fail Never when condition does not return before timeout

Track whether the condition completed at least once. If waitFor
elapses before the first evaluation returns, report a failure instead
of passing without checking.

Fixes #1654

Author: wyf027

assert/assertions.go

@@ -2166,18 +2166,23 @@ func Never(t TestingT, condition func() bool, waitFor time.Duration, tick time.D
 	defer ticker.Stop()
 
 	var tickC <-chan time.Time
+	checked := false
 
 	// Check the condition once first on the initial call.
 	go checkCond()
 
 	for {
 		select {
 		case <-timer.C:
+			if !checked {
+				return Fail(t, "Condition never completed before timeout", msgAndArgs...)
+			}
 			return true
 		case <-tickC:
 			tickC = nil
 			go checkCond()
 		case v := <-ch:
+			checked = true
 			if v {
 				return Fail(t, "Condition satisfied", msgAndArgs...)
 			}

assert/assertions_test.go

@@ -3634,6 +3634,18 @@ func TestNeverFailQuickly(t *testing.T) {
 	False(t, Never(mockT, condition, 100*time.Millisecond, time.Second))
 }
 
+func TestNeverTimeoutBeforeConditionReturns(t *testing.T) {
+	t.Parallel()
+
+	mockT := new(testing.T)
+
+	condition := func() bool {
+		time.Sleep(2 * time.Second)
+		return true
+	}
+	False(t, Never(mockT, condition, time.Millisecond, time.Second))
+}
+
 func Test_validateEqualArgs(t *testing.T) {
 	t.Parallel()