all: mv v1 to next; imp tests, docs

internal/aghchan/aghchan.go

@@ -6,14 +6,28 @@ import (
 	"time"
 )
 
-// MustReceive panics if it cannot receive a value form c before timeout runs
-// out.
-func MustReceive[T any](c <-chan T, timeout time.Duration) (v T, ok bool) {
+// Receive returns an error if it cannot receive a value form c before timeout
+// runs out.
+func Receive[T any](c <-chan T, timeout time.Duration) (v T, ok bool, err error) {
+	var zero T
 	timeoutCh := time.After(timeout)
 	select {
 	case <-timeoutCh:
-		panic(fmt.Errorf("did not receive after %s", timeout))
+		// TODO(a.garipov): Consider implementing [errors.Aser] for
+		// os.ErrTimeout.
+		return zero, false, fmt.Errorf("did not receive after %s", timeout)
 	case v, ok = <-c:
-		return v, ok
+		return v, ok, nil
 	}
 }
+
+// MustReceive panics if it cannot receive a value form c before timeout runs
+// out.
+func MustReceive[T any](c <-chan T, timeout time.Duration) (v T, ok bool) {
+	v, ok, err := Receive(c, timeout)
+	if err != nil {
+		panic(err)
+	}
+
+	return v, ok
+}