add validator + tests

mail/mail.go

@@ -5,14 +5,18 @@ import (
 	"fmt"
 	"os"
 	"strings"
+
+	"github.com/go-playground/validator/v10"
 )
 
+var validate *validator.Validate
+
 type Email struct {
 	Path      string
-	Sender    string `json:"sender"`
-	Receivers string `json:"receivers"`
-	Subject   string `json:"subject"`
-	Content   string `json:"content"`
+	Sender    string `json:"sender" validate:"required,email"`
+	Receivers string `json:"receivers" validate:"required"`
+	Subject   string `json:"subject" validate:"required"`
+	Content   string `json:"content" validate:"required"`
 }
 
 func FromJSON(path string) (Email, error) {
@@ -27,6 +31,11 @@ func FromJSON(path string) (Email, error) {
 		return mail, err
 	}
 
+	validate = validator.New(validator.WithRequiredStructEnabled())
+	if err := validate.Struct(mail); err != nil {
+		return mail, err
+	}
+
 	return mail, nil
 }
 

mail/mail_test.go

@@ -0,0 +1,60 @@
+package mail
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFromJson(t *testing.T) {
+	t.Run("right format", func(t *testing.T) {
+		f, err := os.CreateTemp("", "temptest-")
+		require.NoError(t, err)
+
+		defer f.Close()
+		defer os.Remove(f.Name())
+
+		data := []byte(`{
+			"sender":"test@test.com",
+			"receivers": "test@test.com, test2@test.com",
+			"subject": "test",
+			"content": "test"
+		}`)
+
+		n, err := f.Write(data)
+		require.NoError(t, err)
+		require.NotEmpty(t, n)
+
+		mail, err := FromJSON(f.Name())
+		require.NoError(t, err)
+
+		assert.Equal(t, "test@test.com", mail.Sender)
+	})
+
+	t.Run("bad sender", func(t *testing.T) {
+		f, err := os.CreateTemp("", "temptest-")
+		require.NoError(t, err)
+
+		defer f.Close()
+		defer os.Remove(f.Name())
+
+		data := []byte(`{
+			"sender":"test",
+			"receivers": "test@test.com, test2@test.com",
+			"subject": "test",
+			"content": "test"
+		}`)
+
+		n, err := f.Write(data)
+		require.NoError(t, err)
+		require.NotEmpty(t, n)
+
+		_, err = FromJSON(f.Name())
+		require.Error(t, err)
+
+		assert.Contains(t, err.Error(), "validation for 'Sender'")
+	})
+
+}