From e7df4cc479bf9232eb8a9b15b996c58be00c44dc Mon Sep 17 00:00:00 2001
From: Jon Lundy <jon@xuu.cc>
Date: Fri, 30 Sep 2022 14:56:10 -0600
Subject: [PATCH] chore: move LoadForUpdate to seporate interface

---
 pkg/es/driver/driver.go                   |   3 +-
 pkg/es/driver/projecter/projecter.go      |   9 +-
 pkg/es/driver/projecter/projector_test.go | 101 +++++++++++++++++++---
 pkg/es/driver/streamer/streamer.go        |   9 +-
 4 files changed, 109 insertions(+), 13 deletions(-)

diff --git a/pkg/es/driver/driver.go b/pkg/es/driver/driver.go
index 175970e..8d63249 100644
--- a/pkg/es/driver/driver.go
+++ b/pkg/es/driver/driver.go
@@ -16,7 +16,8 @@ type EventLog interface {
 	Append(ctx context.Context, events event.Events, version uint64) (uint64, error)
 	FirstIndex(context.Context) (uint64, error)
 	LastIndex(context.Context) (uint64, error)
-
+}
+type EventLogWithUpdate interface {
 	LoadForUpdate(context.Context, event.Aggregate, func(context.Context, event.Aggregate) error) (uint64, error)
 }
 
diff --git a/pkg/es/driver/projecter/projecter.go b/pkg/es/driver/projecter/projecter.go
index 287b081..94ea378 100644
--- a/pkg/es/driver/projecter/projecter.go
+++ b/pkg/es/driver/projecter/projecter.go
@@ -111,7 +111,14 @@ func (w *wrapper) LoadForUpdate(ctx context.Context, a event.Aggregate, fn func(
 	ctx, span := lg.Span(ctx)
 	defer span.End()
 
-	return w.up.LoadForUpdate(ctx, a, fn)
+	up := w.up
+	for up != nil {
+		if up, ok := up.(driver.EventLogWithUpdate); ok {
+			return up.LoadForUpdate(ctx, a, fn)
+		}
+		up = es.Unwrap(up)
+	}
+	return 0, es.ErrNoDriver
 }
 
 func DefaultProjection(e event.Event) []event.Event {
diff --git a/pkg/es/driver/projecter/projector_test.go b/pkg/es/driver/projecter/projector_test.go
index 9aa2ffb..ba26b3e 100644
--- a/pkg/es/driver/projecter/projector_test.go
+++ b/pkg/es/driver/projecter/projector_test.go
@@ -4,26 +4,107 @@ import (
 	"context"
 	"testing"
 
+	"github.com/matryer/is"
+	"github.com/sour-is/ev/pkg/es"
 	"github.com/sour-is/ev/pkg/es/driver"
+	"github.com/sour-is/ev/pkg/es/driver/projecter"
+	"github.com/sour-is/ev/pkg/es/event"
 )
 
 type mockDriver struct {
-	onOpen     func()
-	onEventLog func()
-}
-
-// EventLog implements driver.Driver
-func (*mockDriver) EventLog(ctx context.Context, streamID string) (driver.EventLog, error) {
-	panic("unimplemented")
+	onOpen     func(context.Context, string) (driver.Driver, error)
+	onEventLog func(context.Context, string) (driver.EventLog, error)
 }
 
 // Open implements driver.Driver
-func (*mockDriver) Open(ctx context.Context, dsn string) (driver.Driver, error) {
+func (m *mockDriver) Open(ctx context.Context, dsn string) (driver.Driver, error) {
+	if m.onOpen != nil {
+		return m.onOpen(ctx, dsn)
+	}
+	panic("unimplemented")
+}
+
+// EventLog implements driver.Driver
+func (m *mockDriver) EventLog(ctx context.Context, streamID string) (driver.EventLog, error) {
+	if m.onEventLog != nil {
+		return m.onEventLog(ctx, streamID)
+	}
 	panic("unimplemented")
 }
 
 var _ driver.Driver = (*mockDriver)(nil)
 
-func TestProjecter(t *testing.T) {
-
+type mockEventLog struct {
+	onAppend     func(context.Context, event.Events, uint64) (uint64, error)
+	onFirstIndex func(context.Context) (uint64, error)
+	onLastIndex  func(context.Context) (uint64, error)
+	onRead       func(context.Context, int64, int64) (event.Events, error)
+}
+
+// Append implements driver.EventLog
+func (m *mockEventLog) Append(ctx context.Context, events event.Events, version uint64) (uint64, error) {
+	if m.onAppend != nil {
+		return m.onAppend(ctx, events, version)
+	}
+	panic("unimplemented")
+}
+
+// FirstIndex implements driver.EventLog
+func (m *mockEventLog) FirstIndex(ctx context.Context) (uint64, error) {
+	if m.onFirstIndex != nil {
+		return m.onFirstIndex(ctx)
+	}
+	panic("unimplemented")
+}
+
+// LastIndex implements driver.EventLog
+func (m *mockEventLog) LastIndex(ctx context.Context) (uint64, error) {
+	if m.onLastIndex != nil {
+		return m.onLastIndex(ctx)
+	}
+	panic("unimplemented")
+}
+
+// Read implements driver.EventLog
+func (m *mockEventLog) Read(ctx context.Context, pos int64, count int64) (event.Events, error) {
+	if m.onRead != nil {
+		return m.onRead(ctx, pos, count)
+	}
+
+	panic("unimplemented")
+}
+
+var _ driver.EventLog = (*mockEventLog)(nil)
+
+func TestProjecter(t *testing.T) {
+	is := is.New(t)
+	ctx := context.Background()
+
+	mockEL := &mockEventLog{}
+	mockEL.onRead = func(ctx context.Context, i1, i2 int64) (event.Events, error) {
+		return event.NewEvents(), nil
+	}
+
+	mock := &mockDriver{}
+	mock.onOpen = func(ctx context.Context, s string) (driver.Driver, error) {
+		return mock, nil
+	}
+	mock.onEventLog = func(ctx context.Context, s string) (driver.EventLog, error) {
+		return mockEL, nil
+	}
+
+	es.Init(ctx)
+	es.Register(ctx, "mock", mock)
+
+	es, err := es.Open(
+		ctx,
+		"mock:",
+		projecter.New(ctx, projecter.DefaultProjection),
+	)
+
+	is.NoErr(err)
+
+	_, err = es.Read(ctx, "test", 0, 1)
+
+	is.NoErr(err)
 }
diff --git a/pkg/es/driver/streamer/streamer.go b/pkg/es/driver/streamer/streamer.go
index 5faa065..ad5b27a 100644
--- a/pkg/es/driver/streamer/streamer.go
+++ b/pkg/es/driver/streamer/streamer.go
@@ -182,7 +182,14 @@ func (w *wrapper) LoadForUpdate(ctx context.Context, a event.Aggregate, fn func(
 	ctx, span := lg.Span(ctx)
 	defer span.End()
 
-	return w.up.LoadForUpdate(ctx, a, fn)
+	up := w.up
+	for up != nil {
+		if up, ok := up.(driver.EventLogWithUpdate); ok {
+			return up.LoadForUpdate(ctx, a, fn)
+		}
+		up = es.Unwrap(up)
+	}
+	return 0, es.ErrNoDriver
 }
 
 type position struct {