From 403630ad31652cf24096fe857d65e8c36682c639 Mon Sep 17 00:00:00 2001
From: Vibhu Pandey <vibhupandey28@gmail.com>
Date: Sat, 24 May 2025 23:53:54 +0530
Subject: [PATCH] feat(signoz): compile time check for dependency injection
 (#8033)

---
 pkg/emailing/emailingtest/provider.go | 28 +++++++++++++++++++++
 pkg/signoz/handler_test.go            | 36 +++++++++++++++++++++++++++
 pkg/signoz/module_test.go             | 34 +++++++++++++++++++++++++
 3 files changed, 98 insertions(+)
 create mode 100644 pkg/emailing/emailingtest/provider.go
 create mode 100644 pkg/signoz/handler_test.go
 create mode 100644 pkg/signoz/module_test.go

diff --git a/pkg/emailing/emailingtest/provider.go b/pkg/emailing/emailingtest/provider.go
new file mode 100644
index 0000000000..1db2b8d997
--- /dev/null
+++ b/pkg/emailing/emailingtest/provider.go
@@ -0,0 +1,28 @@
+package emailingtest
+
+import (
+	"context"
+
+	"github.com/SigNoz/signoz/pkg/emailing"
+	"github.com/SigNoz/signoz/pkg/types/emailtypes"
+)
+
+var _ emailing.Emailing = (*Provider)(nil)
+
+type Provider struct {
+	SentEmailCountByTo           map[string]int
+	SentEmailCountByTemplateName map[emailtypes.TemplateName]int
+}
+
+func New() *Provider {
+	return &Provider{
+		SentEmailCountByTo:           make(map[string]int),
+		SentEmailCountByTemplateName: make(map[emailtypes.TemplateName]int),
+	}
+}
+
+func (provider *Provider) SendHTML(ctx context.Context, to string, subject string, templateName emailtypes.TemplateName, data map[string]any) error {
+	provider.SentEmailCountByTo[to]++
+	provider.SentEmailCountByTemplateName[templateName]++
+	return nil
+}
diff --git a/pkg/signoz/handler_test.go b/pkg/signoz/handler_test.go
new file mode 100644
index 0000000000..d28ab38376
--- /dev/null
+++ b/pkg/signoz/handler_test.go
@@ -0,0 +1,36 @@
+package signoz
+
+import (
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/SigNoz/signoz/pkg/emailing/emailingtest"
+	"github.com/SigNoz/signoz/pkg/factory/factorytest"
+	"github.com/SigNoz/signoz/pkg/modules/user/impluser"
+	"github.com/SigNoz/signoz/pkg/sqlstore"
+	"github.com/SigNoz/signoz/pkg/sqlstore/sqlstoretest"
+	"github.com/SigNoz/signoz/pkg/types/authtypes"
+	"github.com/stretchr/testify/assert"
+)
+
+// This is a test to ensure that all fields of the handlers are initialized.
+// It also helps us catch these errors at compile time instead of runtime.
+func TestNewHandlers(t *testing.T) {
+	sqlstore := sqlstoretest.New(sqlstore.Config{Provider: "sqlite"}, sqlmock.QueryMatcherEqual)
+	jwt := authtypes.NewJWT("", 1*time.Hour, 1*time.Hour)
+	emailing := emailingtest.New()
+	providerSettings := factorytest.NewSettings()
+	userModule := impluser.NewModule(impluser.NewStore(sqlstore), jwt, emailing, providerSettings)
+	userHandler := impluser.NewHandler(userModule)
+
+	modules := NewModules(sqlstore, userModule)
+	handlers := NewHandlers(modules, userHandler)
+
+	reflectVal := reflect.ValueOf(handlers)
+	for i := 0; i < reflectVal.NumField(); i++ {
+		f := reflectVal.Field(i)
+		assert.False(t, f.IsZero(), "%s handler has not been initialized", reflectVal.Type().Field(i).Name)
+	}
+}
diff --git a/pkg/signoz/module_test.go b/pkg/signoz/module_test.go
new file mode 100644
index 0000000000..566cb41e0e
--- /dev/null
+++ b/pkg/signoz/module_test.go
@@ -0,0 +1,34 @@
+package signoz
+
+import (
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/SigNoz/signoz/pkg/emailing/emailingtest"
+	"github.com/SigNoz/signoz/pkg/factory/factorytest"
+	"github.com/SigNoz/signoz/pkg/modules/user/impluser"
+	"github.com/SigNoz/signoz/pkg/sqlstore"
+	"github.com/SigNoz/signoz/pkg/sqlstore/sqlstoretest"
+	"github.com/SigNoz/signoz/pkg/types/authtypes"
+	"github.com/stretchr/testify/assert"
+)
+
+// This is a test to ensure that all fields of the modules are initialized.
+// It also helps us catch these errors at compile time instead of runtime.
+func TestNewModules(t *testing.T) {
+	sqlstore := sqlstoretest.New(sqlstore.Config{Provider: "sqlite"}, sqlmock.QueryMatcherEqual)
+	jwt := authtypes.NewJWT("", 1*time.Hour, 1*time.Hour)
+	emailing := emailingtest.New()
+	providerSettings := factorytest.NewSettings()
+	userModule := impluser.NewModule(impluser.NewStore(sqlstore), jwt, emailing, providerSettings)
+
+	modules := NewModules(sqlstore, userModule)
+
+	reflectVal := reflect.ValueOf(modules)
+	for i := 0; i < reflectVal.NumField(); i++ {
+		f := reflectVal.Field(i)
+		assert.False(t, f.IsZero(), "%s module has not been initialized", reflectVal.Type().Field(i).Name)
+	}
+}