✨ Add WithContext function for cancellation

waiterr_test.go

@@ -1,6 +1,7 @@
 package waiterr_test
 
 import (
+	"context"
 	"errors"
 	"testing"
 	"testing/synctest"
@@ -114,3 +115,29 @@ func TestUnwrap(tt *testing.T) {
 		be.Equal(t, weNoErr.Unwrap(), nil)
 	})
 }
+
+func TestWithContext(tt *testing.T) {
+	tt.Run("with error", func(tt2 *testing.T) {
+		er1 := errors.New("uh-oh")
+		er2 := errors.New("oops")
+		synctest.Test(tt2, func(t *testing.T) {
+			we, ctx := waiterr.WithContext(t.Context())
+			we.Go(func() error { return er1 })
+			synctest.Wait() // Ensure it finishes first
+			we.Go(func() error { return er2 })
+
+			er := context.Cause(ctx)
+			be.Err(t, er, er1)
+			be.True(t, !errors.Is(er, er2))
+		})
+	})
+
+	tt.Run("no error", func(t *testing.T) {
+		we, ctx := waiterr.WithContext(t.Context())
+		we.Go(func() error { return nil })
+		we.Go(func() error { return nil })
+		er := we.Wait()
+		be.Err(t, er, nil)
+		be.Err(t, context.Cause(ctx), context.Canceled)
+	})
+}