refactor: simplify app_config service and fix race conditions (#423)

backend/internal/model/app_config_test.go

@@ -1,10 +1,16 @@
-package model
+// We use model_test here to avoid an import cycle
+package model_test
 
 import (
+	"reflect"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+
+	"github.com/pocket-id/pocket-id/backend/internal/dto"
+	"github.com/pocket-id/pocket-id/backend/internal/model"
 )
 
 func TestAppConfigVariable_AsMinutesDuration(t *testing.T) {
@@ -48,7 +54,7 @@ func TestAppConfigVariable_AsMinutesDuration(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			configVar := AppConfigVariable{
+			configVar := model.AppConfigVariable{
 				Value: tt.value,
 			}
 
@@ -58,3 +64,66 @@ func TestAppConfigVariable_AsMinutesDuration(t *testing.T) {
 		})
 	}
 }
+
+// This test ensures that the model.AppConfig and dto.AppConfigUpdateDto structs match:
+// - They should have the same properties, where the "json" tag of dto.AppConfigUpdateDto should match the "key" tag in model.AppConfig
+// - dto.AppConfigDto should not include "internal" fields from model.AppConfig
+// This test is primarily meant to catch discrepancies between the two structs as fields are added or removed over time
+func TestAppConfigStructMatchesUpdateDto(t *testing.T) {
+	appConfigType := reflect.TypeOf(model.AppConfig{})
+	updateDtoType := reflect.TypeOf(dto.AppConfigUpdateDto{})
+
+	// Process AppConfig fields
+	appConfigFields := make(map[string]string)
+	for i := 0; i < appConfigType.NumField(); i++ {
+		field := appConfigType.Field(i)
+		if field.Tag.Get("key") == "" {
+			// Skip internal fields
+			continue
+		}
+
+		// Extract the key name from the tag (takes the part before any comma)
+		keyTag := field.Tag.Get("key")
+		keyName, _, _ := strings.Cut(keyTag, ",")
+
+		appConfigFields[field.Name] = keyName
+	}
+
+	// Process AppConfigUpdateDto fields
+	dtoFields := make(map[string]string)
+	for i := 0; i < updateDtoType.NumField(); i++ {
+		field := updateDtoType.Field(i)
+
+		// Extract the json name from the tag (takes the part before any binding constraints)
+		jsonTag := field.Tag.Get("json")
+		jsonName, _, _ := strings.Cut(jsonTag, ",")
+
+		dtoFields[jsonName] = field.Name
+	}
+
+	// Verify every AppConfig field has a matching DTO field with the same name
+	for fieldName, keyName := range appConfigFields {
+		if strings.HasSuffix(fieldName, "ImageType") {
+			// Skip internal fields that shouldn't be in the DTO
+			continue
+		}
+
+		// Check if there's a DTO field with a matching JSON tag
+		_, exists := dtoFields[keyName]
+		assert.True(t, exists, "Field %s with key '%s' in AppConfig has no matching field in AppConfigUpdateDto", fieldName, keyName)
+	}
+
+	// Verify every DTO field has a matching AppConfig field
+	for jsonName, fieldName := range dtoFields {
+		// Find a matching field in AppConfig by key tag
+		found := false
+		for _, keyName := range appConfigFields {
+			if keyName == jsonName {
+				found = true
+				break
+			}
+		}
+
+		assert.True(t, found, "Field %s with json tag '%s' in AppConfigUpdateDto has no matching field in AppConfig", fieldName, jsonName)
+	}
+}