Added testtx

README.md

@@ -138,5 +138,9 @@ This way, your infrastructural concerns stay in the infrastructure layer where t
 
 *Please note that this is only one way of using the abstraction*
 
+## Testing
+You can use `testtx.New()` as a convenient test helper. It creates a test transactor which only calls f without
+setting any sort of transaction in the `ctx` and preserves any errors raised by f in `.Err` field.
+
 ## Next up
-- [ ] Add a way to configure transaction isolation levels for individual drivers eg. `pgxtx.NewDBFromPool(pool, ...opts)`
+- Add isolation level configuration for individual drivers eg. through `pgxtx.NewDBFromPool(pool, ...opts)`

testtx/testtx.go

@@ -0,0 +1,17 @@
+package testtx
+
+import "context"
+
+func New() *TX {
+	return &TX{}
+}
+
+type TX struct {
+	Err error
+}
+
+func (t *TX) WithTransaction(ctx context.Context, f func(ctx context.Context) error) error {
+	t.Err = f(ctx)
+
+	return t.Err
+}

testtx/testtx_test.go

@@ -0,0 +1,52 @@
+package testtx_test
+
+import (
+	"context"
+	"fmt"
+	"github.com/aneshas/tx/v2"
+	"github.com/aneshas/tx/v2/testtx"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+type svc struct {
+	tx.Transactor
+
+	DidSomething bool
+}
+
+func (s *svc) doSomething(ctx context.Context, err error) error {
+	return s.WithTransaction(ctx, func(ctx context.Context) error {
+		s.DidSomething = true
+
+		return err
+	})
+}
+
+func TestShould_Delegate_Call(t *testing.T) {
+	transactor := testtx.New()
+
+	s := &svc{
+		Transactor: transactor,
+	}
+
+	err := s.doSomething(context.TODO(), nil)
+
+	assert.NoError(t, err)
+	assert.True(t, s.DidSomething)
+}
+
+func TestShould_Save_Err(t *testing.T) {
+	transactor := testtx.New()
+
+	s := &svc{
+		Transactor: transactor,
+	}
+
+	wantErr := fmt.Errorf("something bad ocurred")
+
+	err := s.doSomething(context.TODO(), wantErr)
+
+	assert.ErrorIs(t, err, wantErr)
+	assert.ErrorIs(t, transactor.Err, wantErr)
+}