Initial commit: Open sourcing all of the Maple Open Technologies code.

native/desktop/maplefile/pkg/httperror/httperror.go

@@ -0,0 +1,146 @@
+package httperror
+
+// This package introduces a new `error` type that combines an HTTP status code and a message.
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+)
+
+// HTTPError represents an http error that occurred while handling a request
+type HTTPError struct {
+	Code   int                `json:"-"` // HTTP Status code. We use `-` to skip json marshaling.
+	Errors *map[string]string `json:"-"` // The original error. Same reason as above.
+}
+
+// New creates a new HTTPError instance with a multi-field errors.
+func New(statusCode int, errorsMap *map[string]string) error {
+	return HTTPError{
+		Code:   statusCode,
+		Errors: errorsMap,
+	}
+}
+
+// NewForSingleField create a new HTTPError instance for a single field. This is a convinience constructor.
+func NewForSingleField(statusCode int, field string, message string) error {
+	return HTTPError{
+		Code:   statusCode,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// NewForBadRequest create a new HTTPError instance pertaining to 403 bad requests with the multi-errors. This is a convinience constructor.
+func NewForBadRequest(err *map[string]string) error {
+	return HTTPError{
+		Code:   http.StatusBadRequest,
+		Errors: err,
+	}
+}
+
+// NewForBadRequestWithSingleField create a new HTTPError instance pertaining to 403 bad requests for a single field. This is a convinience constructor.
+func NewForBadRequestWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusBadRequest,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+func NewForInternalServerErrorWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusInternalServerError,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// NewForNotFoundWithSingleField create a new HTTPError instance pertaining to 404 not found for a single field. This is a convinience constructor.
+func NewForNotFoundWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusNotFound,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// NewForServiceUnavailableWithSingleField create a new HTTPError instance pertaining service unavailable for a single field. This is a convinience constructor.
+func NewForServiceUnavailableWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusServiceUnavailable,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// NewForLockedWithSingleField create a new HTTPError instance pertaining to 424 locked for a single field. This is a convinience constructor.
+func NewForLockedWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusLocked,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// NewForForbiddenWithSingleField create a new HTTPError instance pertaining to 403 bad requests for a single field. This is a convinience constructor.
+func NewForForbiddenWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusForbidden,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// NewForUnauthorizedWithSingleField create a new HTTPError instance pertaining to 401 unauthorized for a single field. This is a convinience constructor.
+func NewForUnauthorizedWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusUnauthorized,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// NewForGoneWithSingleField create a new HTTPError instance pertaining to 410 gone for a single field. This is a convinience constructor.
+func NewForGoneWithSingleField(field string, message string) error {
+	return HTTPError{
+		Code:   http.StatusGone,
+		Errors: &map[string]string{field: message},
+	}
+}
+
+// Error function used to implement the `error` interface for returning errors.
+func (err HTTPError) Error() string {
+	b, e := json.Marshal(err.Errors)
+	if e != nil { // Defensive code
+		return e.Error()
+	}
+	return string(b)
+}
+
+// ResponseError function returns the HTTP error response based on the httpcode used.
+func ResponseError(rw http.ResponseWriter, err error) {
+	// Copied from:
+	// https://dev.to/tigorlazuardi/go-creating-custom-error-wrapper-and-do-proper-error-equality-check-11k7
+
+	rw.Header().Set("Content-Type", "Application/json")
+
+	//
+	// CASE 1 OF 2: Handle API Errors.
+	//
+
+	var ew HTTPError
+	if errors.As(err, &ew) {
+		rw.WriteHeader(ew.Code)
+		_ = json.NewEncoder(rw).Encode(ew.Errors)
+		return
+	}
+
+	//
+	// CASE 2 OF 2: Handle non ErrorWrapper types.
+	//
+
+	rw.WriteHeader(http.StatusInternalServerError)
+
+	_ = json.NewEncoder(rw).Encode(err.Error())
+}
+
+// NewForInternalServerError create a new HTTPError instance pertaining to 500 internal server error with the multi-errors. This is a convinience constructor.
+func NewForInternalServerError(err string) error {
+	return HTTPError{
+		Code:   http.StatusInternalServerError,
+		Errors: &map[string]string{"message": err},
+	}
+}