📝 docs: add ADR for staged-only Git hooks formatting

- Add ADR-0012 documenting the decision to format only staged Go files
- Update ADR README.md with new entry
- Document rationale, alternatives, and verification results
- Include future considerations for monitoring and CI/CD integration

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

pkg/bdd/steps/steps.go

@@ -48,14 +48,14 @@ func (sc *StepContext) iRequestTheHealthEndpoint() error {
 func (sc *StepContext) theResponseShouldBe(arg1, arg2 string) error {
 	// The regex captures the full JSON from the feature file, including quotes
 	// We need to extract just the key and value without the surrounding quotes and backslashes
-	
+
 	// Remove the surrounding quotes and backslashes
 	cleanArg1 := strings.Trim(arg1, `"\`)
 	cleanArg2 := strings.Trim(arg2, `"\`)
-	
+
 	// Build the expected JSON string
 	expected := fmt.Sprintf(`{"%s":"%s"}`, cleanArg1, cleanArg2)
-	
+
 	return sc.client.ExpectResponseBody(expected)
 }
 
@@ -70,7 +70,7 @@ func (sc *StepContext) theServerIsRunningWithV2Enabled() error {
 	if err := sc.client.Request("GET", "/api/ready", nil); err != nil {
 		return err
 	}
-	
+
 	// Check if v2 endpoint is available (should return 405 Method Not Allowed for GET, which means endpoint exists)
 	// If v2 is disabled, this will return 404
 	resp, err := sc.client.CustomRequest("GET", "/api/v2/greet", nil)
@@ -78,13 +78,13 @@ func (sc *StepContext) theServerIsRunningWithV2Enabled() error {
 		return err
 	}
 	defer resp.Body.Close()
-	
+
 	// If we get 405, v2 is enabled (endpoint exists but doesn't allow GET)
 	// If we get 404, v2 is disabled
 	if resp.StatusCode == 404 {
 		return fmt.Errorf("v2 endpoint not available - v2 feature flag not enabled")
 	}
-	
+
 	return nil
 }
 

pkg/bdd/testserver/client.go

@@ -23,7 +23,7 @@ func NewClient(server *Server) *Client {
 
 func (c *Client) Request(method, path string, body interface{}) error {
 	url := c.server.GetBaseURL() + path
-	
+
 	var reqBody io.Reader
 	if body != nil {
 		// Handle different body types
@@ -42,12 +42,12 @@ func (c *Client) Request(method, path string, body interface{}) error {
 			return fmt.Errorf("unsupported body type: %T", body)
 		}
 	}
-	
+
 	req, err := http.NewRequest(method, url, reqBody)
 	if err != nil {
 		return fmt.Errorf("failed to create request: %w", err)
 	}
-	
+
 	// Set content type for JSON bodies
 	if body != nil && reqBody != nil {
 		req.Header.Set("Content-Type", "application/json")
@@ -70,7 +70,7 @@ func (c *Client) Request(method, path string, body interface{}) error {
 
 func (c *Client) CustomRequest(method, path string, body interface{}) (*http.Response, error) {
 	url := c.server.GetBaseURL() + path
-	
+
 	var reqBody io.Reader
 	if body != nil {
 		// Handle different body types
@@ -89,12 +89,12 @@ func (c *Client) CustomRequest(method, path string, body interface{}) (*http.Res
 			return nil, fmt.Errorf("unsupported body type: %T", body)
 		}
 	}
-	
+
 	req, err := http.NewRequest(method, url, reqBody)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create request: %w", err)
 	}
-	
+
 	// Set content type for JSON bodies
 	if body != nil && reqBody != nil {
 		req.Header.Set("Content-Type", "application/json")
@@ -104,7 +104,7 @@ func (c *Client) CustomRequest(method, path string, body interface{}) (*http.Res
 	if err != nil {
 		return nil, fmt.Errorf("request failed: %w", err)
 	}
-	
+
 	// Don't close the body here - let the caller handle it
 	c.lastResp = resp
 	c.lastBody, err = io.ReadAll(resp.Body)
@@ -123,7 +123,7 @@ func (c *Client) ExpectResponseBody(expected string) error {
 	actual := string(c.lastBody)
 	// Trim trailing newline if present (common in JSON responses)
 	actual = strings.TrimSuffix(actual, "\n")
-	
+
 	if actual != expected {
 		return fmt.Errorf("expected response body %q, got %q", expected, actual)
 	}

pkg/bdd/testserver/server.go

@@ -12,7 +12,7 @@ import (
 )
 
 type Server struct {
-	httpServer  *http.Server
+	httpServer *http.Server
 	port       int
 	baseURL    string
 }
@@ -94,8 +94,8 @@ func createTestConfig(port int) *config.Config {
 			Timeout: 5 * time.Second,
 		},
 		Logging: config.LoggingConfig{
-			JSON:   false,
-			Level:  "trace",
+			JSON:  false,
+			Level: "trace",
 		},
 		Telemetry: config.TelemetryConfig{
 			Enabled: false,

pkg/config/config.go

@@ -33,9 +33,9 @@ type ShutdownConfig struct {
 
 // LoggingConfig holds logging-related configuration
 type LoggingConfig struct {
-	JSON    bool   `mapstructure:"json"`
-	Level   string `mapstructure:"level"`
-	Output  string `mapstructure:"output"`
+	JSON   bool   `mapstructure:"json"`
+	Level  string `mapstructure:"level"`
+	Output string `mapstructure:"output"`
 }
 
 // TelemetryConfig holds OpenTelemetry-related configuration
@@ -63,7 +63,7 @@ type SamplerConfig struct {
 // To specify a custom config file path, set DLC_CONFIG_FILE environment variable
 func LoadConfig() (*Config, error) {
 	v := viper.New()
-	
+
 	// Set up initial console logging for config loading messages
 	consoleWriter := zerolog.ConsoleWriter{Out: os.Stderr}
 	log.Logger = log.Output(consoleWriter)
@@ -221,7 +221,7 @@ func (c *Config) SetupLogging() {
 
 	// Setup log output
 	c.setupLogOutput()
-	
+
 	zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
 }
 
@@ -255,14 +255,14 @@ func (c *Config) setupLogOutput() {
 		// Use stderr by default
 		return
 	}
-	
+
 	// Open the log file
 	file, err := os.OpenFile(output, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
 	if err != nil {
 		log.Error().Err(err).Str("output", output).Msg("Failed to open log file, using stderr")
 		return
 	}
-	
+
 	// Set the log output
 	log.Logger = log.Output(file)
 	log.Trace().Str("output", output).Msg("Logging to file")

pkg/greet/api_v2.go

@@ -4,9 +4,9 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
-	"strconv"
 	"io"
 	"net/http"
+	"strconv"
 
 	"DanceLessonsCoach/pkg/validation"
 	"github.com/go-chi/chi/v5"
@@ -22,7 +22,7 @@ type ApiV2Greet interface {
 }
 
 type apiV2GreetHandler struct {
-	greeter    GreeterV2
+	greeter   GreeterV2
 	validator *validation.Validator
 }
 
@@ -108,4 +108,4 @@ func (h *apiV2GreetHandler) handleValidationError(w http.ResponseWriter, err err
 func (h *apiV2GreetHandler) writeJSONResponse(w http.ResponseWriter, message string) {
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(greetResponse{Message: message})
-}
+}

pkg/greet/greet.go

@@ -21,4 +21,4 @@ func (s *Service) Greet(ctx context.Context, name string) string {
 		return "Hello world!"
 	}
 	return "Hello " + name + "!"
-}
+}

pkg/greet/greet_v2.go

@@ -21,4 +21,4 @@ func (s *ServiceV2) GreetV2(ctx context.Context, name string) string {
 		return "Hello my friend!"
 	}
 	return "Hello my friend " + name + "!"
-}
+}

pkg/greet/greet_v2_test.go

@@ -25,4 +25,4 @@ func TestServiceV2_GreetV2(t *testing.T) {
 			}
 		})
 	}
-}
+}

pkg/server/server.go

@@ -10,8 +10,8 @@ import (
 
 	"DanceLessonsCoach/pkg/config"
 	"DanceLessonsCoach/pkg/greet"
-	"DanceLessonsCoach/pkg/validation"
 	"DanceLessonsCoach/pkg/telemetry"
+	"DanceLessonsCoach/pkg/validation"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 

pkg/validation/validator.go

@@ -8,9 +8,9 @@ import (
 	"strings"
 
 	"github.com/go-playground/locales/en"
-	en_translations "github.com/go-playground/validator/v10/translations/en"
-	"github.com/go-playground/validator/v10"
 	ut "github.com/go-playground/universal-translator"
+	"github.com/go-playground/validator/v10"
+	en_translations "github.com/go-playground/validator/v10/translations/en"
 )
 
 // Validator wraps the go-playground/validator with custom error handling
@@ -82,7 +82,7 @@ func (v *Validator) formatValidationErrors(errors validator.ValidationErrors) er
 
 		// Get custom error message
 		message := fmt.Errorf("%s failed validation for '%s'", field, tag).Error()
-		
+
 		// Add parameter if available
 		if param != "" {
 			message += fmt.Sprintf(" (parameter: %s)", param)
@@ -120,4 +120,4 @@ func GetValidatorFromConfig(cfg *config.Config) (*Validator, error) {
 	// For now, config doesn't affect validator creation
 	// But this allows future configuration (e.g., language, strict mode)
 	return NewValidator()
-}
+}