rewrite file serving system

internal/message/error.go

@@ -0,0 +1,106 @@
+package message
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+)
+
+// ErrorWithCode wraps an internal error with an http code, and a 'safe' version of
+// the error that can be served to clients without revealing internal business logic.
+//
+// A typical use of this error would be to first log the Original error, then return
+// the Safe error and the StatusCode to an API caller.
+type ErrorWithCode interface {
+	// Error returns the original internal error for debugging within the GoToSocial logs.
+	// This should *NEVER* be returned to a client as it may contain sensitive information.
+	Error() string
+	// Safe returns the API-safe version of the error for serialization towards a client.
+	// There's not much point logging this internally because it won't contain much helpful information.
+	Safe() string
+	//  Code returns the status code for serving to a client.
+	Code() int
+}
+
+type errorWithCode struct {
+	original error
+	safe     error
+	code     int
+}
+
+func (e errorWithCode) Error() string {
+	return e.original.Error()
+}
+
+func (e errorWithCode) Safe() string {
+	return e.safe.Error()
+}
+
+func (e errorWithCode) Code() int {
+	return e.code
+}
+
+// NewErrorBadRequest returns an ErrorWithCode 400 with the given original error and optional help text.
+func NewErrorBadRequest(original error, helpText ...string) ErrorWithCode {
+	safe := "bad request"
+	if helpText != nil {
+		safe = safe + ": " + strings.Join(helpText, ": ")
+	}
+	return errorWithCode{
+		original: original,
+		safe:     errors.New(safe),
+		code:     http.StatusBadRequest,
+	}
+}
+
+// NewErrorNotAuthorized returns an ErrorWithCode 401 with the given original error and optional help text.
+func NewErrorNotAuthorized(original error, helpText ...string) ErrorWithCode {
+	safe := "not authorized"
+	if helpText != nil {
+		safe = safe + ": " + strings.Join(helpText, ": ")
+	}
+	return errorWithCode{
+		original: original,
+		safe:     errors.New(safe),
+		code:     http.StatusUnauthorized,
+	}
+}
+
+// NewErrorForbidden returns an ErrorWithCode 403 with the given original error and optional help text.
+func NewErrorForbidden(original error, helpText ...string) ErrorWithCode {
+	safe := "forbidden"
+	if helpText != nil {
+		safe = safe + ": " + strings.Join(helpText, ": ")
+	}
+	return errorWithCode{
+		original: original,
+		safe:     errors.New(safe),
+		code:     http.StatusForbidden,
+	}
+}
+
+// NewErrorNotFound returns an ErrorWithCode 404 with the given original error and optional help text.
+func NewErrorNotFound(original error, helpText ...string) ErrorWithCode {
+	safe := "404 not found"
+	if helpText != nil {
+		safe = safe + ": " + strings.Join(helpText, ": ")
+	}
+	return errorWithCode{
+		original: original,
+		safe:     errors.New(safe),
+		code:     http.StatusNotFound,
+	}
+}
+
+// NewErrorInternalError returns an ErrorWithCode 500 with the given original error and optional help text.
+func NewErrorInternalError(original error, helpText ...string) ErrorWithCode {
+	safe := "internal server error"
+	if helpText != nil {
+		safe = safe + ": " + strings.Join(helpText, ": ")
+	}
+	return errorWithCode{
+		original: original,
+		safe:     errors.New(safe),
+		code:     http.StatusInternalServerError,
+	}
+}