feat: improve error handling

internal/lib/errors.go

@@ -2,14 +2,87 @@ package lib
 
 import (
 	"errors"
+	"fmt"
+	"go.uber.org/zap/zapcore"
+	"runtime"
 )
 
-var (
-	ErrInternal     = errors.New("internal")
-	ErrUnexpected   = errors.New("unexpected")
-	ErrNoPermission = errors.New("no permission")
+type code uint8
+
+const (
+	ErrValidationFailed code = 1
+	ErrInternal         code = 2
+	ErrExternal         code = 3
+	ErrNoPermission     code = 4
+	ErrUnknown          code = 5
+	ErrDeadlineExceeded code = 6
+	ErrNotFound         code = 7
+	ErrAlreadyExists    code = 8
+	ErrConflict         code = 9
+	ErrUnimplemented    code = 10
+	ErrBadInput         code = 11
+	ErrUnauthenticated  code = 12
 )
 
+func (c code) String() string {
+	switch {
+	case errors.Is(c, ErrValidationFailed):
+		return "validation error"
+	case errors.Is(c, ErrInternal):
+		return "internal error"
+	case errors.Is(c, ErrExternal):
+		return "external error"
+	case errors.Is(c, ErrNoPermission):
+		return "permission error"
+	case errors.Is(c, ErrUnknown):
+		return "unknown error"
+	case errors.Is(c, ErrDeadlineExceeded):
+		return "deadline error"
+	case errors.Is(c, ErrNotFound):
+		return "not found error"
+	case errors.Is(c, ErrAlreadyExists):
+		return "already exists error"
+	case errors.Is(c, ErrConflict):
+		return "conflict error"
+	case errors.Is(c, ErrUnimplemented):
+		return "unimplemented error"
+	case errors.Is(c, ErrBadInput):
+		return "bad input error"
+	}
+
+	panic("unimplemented")
+}
+
+func (c code) Error() string {
+	return c.String()
+}
+
+type layer uint8
+
+const (
+	LayerTransport layer = 1
+	LayerService   layer = 2
+	LayerStorage   layer = 3
+)
+
+func (l layer) String() string {
+	switch l {
+	case LayerTransport:
+		return "transport"
+	case LayerService:
+		return "service"
+	case LayerStorage:
+		return "storage"
+	}
+
+	panic("unimplemented")
+}
+
+func location(skip int) string {
+	_, file, line, _ := runtime.Caller(skip)
+	return fmt.Sprintf("%s:%d", file, line)
+}
+
 var (
 	ErrBadRole = errors.New("bad role")
 )
@@ -18,3 +91,51 @@ var (
 	ErrBadTestingStrategy = errors.New("bad testing strategy")
 	ErrBadResult          = errors.New("bad result")
 )
+
+type Error struct {
+	src   error
+	layer layer
+	code  code
+	msg   string
+	loc   string
+}
+
+func wrap(src error, layer layer, class code, msg string, loc string) *Error {
+	return &Error{
+		src:   src,
+		layer: layer,
+		code:  class,
+		msg:   msg,
+		loc:   loc,
+	}
+}
+
+func (e *Error) Unwrap() []error {
+	return []error{e.src, e.code}
+}
+
+func (e *Error) Error() string {
+	return fmt.Sprintf("%s: %s", e.code.String(), e.msg)
+}
+
+func (e *Error) MarshalLogObject(encoder zapcore.ObjectEncoder) error {
+	if e.src != nil {
+		encoder.AddString("src", e.src.Error())
+	}
+	encoder.AddString("layer", e.layer.String())
+	encoder.AddString("code", e.code.String())
+	encoder.AddString("msg", e.msg)
+	return nil
+}
+
+func TransportError(src error, code code, msg string) error {
+	return wrap(src, LayerTransport, code, msg, location(2))
+}
+
+func ServiceError(src error, code code, msg string) error {
+	return wrap(src, LayerService, code, msg, location(2))
+}
+
+func StorageError(src error, code code, msg string) error {
+	return wrap(src, LayerStorage, code, msg, location(2))
+}