fix(lint): resolve staticcheck issues and improve code quality (#2941)

* refactor: apply De Morgan’s law to boolean expressions

Author: itsllyaz

bind.go

@@ -155,7 +155,7 @@ func bindData(destination any, data map[string][]string, tag string, dataFiles m
 		isElemInterface := k == reflect.Interface
 		isElemString := k == reflect.String
 		isElemSliceOfStrings := k == reflect.Slice && typ.Elem().Elem().Kind() == reflect.String
-		if !(isElemSliceOfStrings || isElemString || isElemInterface) {
+		if !isElemSliceOfStrings && !isElemString && !isElemInterface {
 			return nil
 		}
 		if val.IsNil() {

binder_generic.go

@@ -49,10 +49,11 @@ const (
 // It returns the typed value and an error if binding fails. Returns ErrNonExistentKey if parameter not found.
 //
 // Empty String Handling:
-//   If the parameter exists but has an empty value, the zero value of type T is returned
-//   with no error. For example, a path parameter with value "" returns (0, nil) for int types.
-//   This differs from standard library behavior where parsing empty strings returns errors.
-//   To treat empty values as errors, validate the result separately or check the raw value.
+//
+//	If the parameter exists but has an empty value, the zero value of type T is returned
+//	with no error. For example, a path parameter with value "" returns (0, nil) for int types.
+//	This differs from standard library behavior where parsing empty strings returns errors.
+//	To treat empty values as errors, validate the result separately or check the raw value.
 //
 // See ParseValue for supported types and options
 func PathParam[T any](c *Context, paramName string, opts ...any) (T, error) {
@@ -74,10 +75,11 @@ func PathParam[T any](c *Context, paramName string, opts ...any) (T, error) {
 // Returns an error only if parsing fails (e.g., "abc" for int type).
 //
 // Example:
-//   id, err := echo.PathParamOr[int](c, "id", 0)
-//   // If "id" is missing: returns (0, nil)
-//   // If "id" is "123": returns (123, nil)
-//   // If "id" is "abc": returns (0, BindingError)
+//
+//	id, err := echo.PathParamOr[int](c, "id", 0)
+//	// If "id" is missing: returns (0, nil)
+//	// If "id" is "123": returns (123, nil)
+//	// If "id" is "abc": returns (0, BindingError)
 //
 // See ParseValue for supported types and options
 func PathParamOr[T any](c *Context, paramName string, defaultValue T, opts ...any) (T, error) {
@@ -97,10 +99,11 @@ func PathParamOr[T any](c *Context, paramName string, defaultValue T, opts ...an
 // It returns the typed value and an error if binding fails. Returns ErrNonExistentKey if parameter not found.
 //
 // Empty String Handling:
-//   If the parameter exists but has an empty value (?key=), the zero value of type T is returned
-//   with no error. For example, "?count=" returns (0, nil) for int types.
-//   This differs from standard library behavior where parsing empty strings returns errors.
-//   To treat empty values as errors, validate the result separately or check the raw value.
+//
+//	If the parameter exists but has an empty value (?key=), the zero value of type T is returned
+//	with no error. For example, "?count=" returns (0, nil) for int types.
+//	This differs from standard library behavior where parsing empty strings returns errors.
+//	To treat empty values as errors, validate the result separately or check the raw value.
 //
 // Behavior Summary:
 //   - Missing key (?other=value): returns (zero, ErrNonExistentKey)
@@ -131,10 +134,11 @@ func QueryParam[T any](c *Context, key string, opts ...any) (T, error) {
 // Returns an error only if parsing fails (e.g., "abc" for int type).
 //
 // Example:
-//   page, err := echo.QueryParamOr[int](c, "page", 1)
-//   // If "page" is missing: returns (1, nil)
-//   // If "page" is "5": returns (5, nil)
-//   // If "page" is "abc": returns (1, BindingError)
+//
+//	page, err := echo.QueryParamOr[int](c, "page", 1)
+//	// If "page" is missing: returns (1, nil)
+//	// If "page" is "5": returns (5, nil)
+//	// If "page" is "abc": returns (1, BindingError)
 //
 // See ParseValue for supported types and options
 func QueryParamOr[T any](c *Context, key string, defaultValue T, opts ...any) (T, error) {
@@ -175,10 +179,11 @@ func QueryParams[T any](c *Context, key string, opts ...any) ([]T, error) {
 // Returns an error only if parsing any value fails.
 //
 // Example:
-//   ids, err := echo.QueryParamsOr[int](c, "ids", []int{})
-//   // If "ids" is missing: returns ([], nil)
-//   // If "ids" is "1&ids=2": returns ([1, 2], nil)
-//   // If "ids" contains "abc": returns ([], BindingError)
+//
+//	ids, err := echo.QueryParamsOr[int](c, "ids", []int{})
+//	// If "ids" is missing: returns ([], nil)
+//	// If "ids" is "1&ids=2": returns ([1, 2], nil)
+//	// If "ids" contains "abc": returns ([], BindingError)
 //
 // See ParseValues for supported types and options
 func QueryParamsOr[T any](c *Context, key string, defaultValue []T, opts ...any) ([]T, error) {
@@ -198,10 +203,11 @@ func QueryParamsOr[T any](c *Context, key string, defaultValue []T, opts ...any)
 // It returns the typed value and an error if binding fails. Returns ErrNonExistentKey if parameter not found.
 //
 // Empty String Handling:
-//   If the form field exists but has an empty value, the zero value of type T is returned
-//   with no error. For example, an empty form field returns (0, nil) for int types.
-//   This differs from standard library behavior where parsing empty strings returns errors.
-//   To treat empty values as errors, validate the result separately or check the raw value.
+//
+//	If the form field exists but has an empty value, the zero value of type T is returned
+//	with no error. For example, an empty form field returns (0, nil) for int types.
+//	This differs from standard library behavior where parsing empty strings returns errors.
+//	To treat empty values as errors, validate the result separately or check the raw value.
 //
 // See ParseValue for supported types and options
 func FormValue[T any](c *Context, key string, opts ...any) (T, error) {
@@ -232,10 +238,11 @@ func FormValue[T any](c *Context, key string, opts ...any) (T, error) {
 // Returns an error only if parsing fails or form parsing errors occur.
 //
 // Example:
-//   limit, err := echo.FormValueOr[int](c, "limit", 100)
-//   // If "limit" is missing: returns (100, nil)
-//   // If "limit" is "50": returns (50, nil)
-//   // If "limit" is "abc": returns (100, BindingError)
+//
+//	limit, err := echo.FormValueOr[int](c, "limit", 100)
+//	// If "limit" is missing: returns (100, nil)
+//	// If "limit" is "50": returns (50, nil)
+//	// If "limit" is "abc": returns (100, BindingError)
 //
 // See ParseValue for supported types and options
 func FormValueOr[T any](c *Context, key string, defaultValue T, opts ...any) (T, error) {
@@ -284,9 +291,10 @@ func FormValues[T any](c *Context, key string, opts ...any) ([]T, error) {
 // Returns an error only if parsing any value fails or form parsing errors occur.
 //
 // Example:
-//   tags, err := echo.FormValuesOr[string](c, "tags", []string{})
-//   // If "tags" is missing: returns ([], nil)
-//   // If form parsing fails: returns (nil, error)
+//
+//	tags, err := echo.FormValuesOr[string](c, "tags", []string{})
+//	// If "tags" is missing: returns ([], nil)
+//	// If form parsing fails: returns (nil, error)
 //
 // See ParseValues for supported types and options
 func FormValuesOr[T any](c *Context, key string, defaultValue []T, opts ...any) ([]T, error) {

middleware/basic_auth.go

@@ -121,7 +121,7 @@ func (config BasicAuthConfig) ToMiddleware() (echo.MiddlewareFunc, error) {
 				if i >= limit {
 					break
 				}
-				if !(len(auth) > l+1 && strings.EqualFold(auth[:l], basic)) {
+				if len(auth) <= l+1 || !strings.EqualFold(auth[:l], basic) {
 					continue
 				}
 				i++

middleware/static.go

@@ -250,7 +250,7 @@ func (config StaticConfig) ToMiddleware() (echo.MiddlewareFunc, error) {
 				}
 
 				var he echo.HTTPStatusCoder
-				if !(errors.As(err, &he) && config.HTML5 && he.StatusCode() == http.StatusNotFound) {
+				if !errors.As(err, &he) || !config.HTML5 || he.StatusCode() != http.StatusNotFound {
 					return err
 				}
 				// is case HTML5 mode is enabled + echo 404 we serve index to the client

response.go

@@ -136,7 +136,7 @@ func UnwrapResponse(rw http.ResponseWriter) (*Response, error) {
 type delayedStatusWriter struct {
 	http.ResponseWriter
 	committed bool
-	status   int
+	status    int
 }
 
 func (w *delayedStatusWriter) WriteHeader(statusCode int) {

route.go

@@ -85,7 +85,7 @@ func (r RouteInfo) Reverse(pathValues ...any) string {
 			// in case of `*` wildcard or `:` (unescaped colon) param we replace everything till next slash or end of path
 			for ; i < l && r.Path[i] != '/'; i++ {
 			}
-			uri.WriteString(fmt.Sprintf("%v", pathValues[n]))
+			fmt.Fprintf(uri, "%v", pathValues[n])
 			n++
 		}
 		if i < l {

router.go

@@ -995,7 +995,7 @@ func (r *DefaultRouter) Route(c *Context) HandlerFunc {
 	var rInfo *RouteInfo
 	if matchedRouteMethod != nil {
 		rHandler = matchedRouteMethod.handler
-		rPath = matchedRouteMethod.RouteInfo.Path
+		rPath = matchedRouteMethod.Path
 		rInfo = matchedRouteMethod.RouteInfo
 	} else {
 		// use previous match as basis. although we have no matching handler we have path match.