v1.0.1

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Roadmap
 
+## [1.0.1] - 2022-02-18
+
+### Added
+
+- Added ability to pre-append `Option`s.
+
 ## [1.0.0] - 2022-02-17
 ### Added
 - Functional `Option`s.

builtin.go

@@ -18,23 +18,32 @@ import (
 //
 // Note: Status code can be redefined, call `SetStatusCode`.
 func NewFailedToError(message string, opts ...Option) error {
-	return New(fmt.Sprintf("failed to %s", message), append(opts, WithStatusCode(http.StatusInternalServerError))...)
+	return New(fmt.Sprintf("failed to %s", message), prependOptions(
+		opts,
+		WithStatusCode(http.StatusInternalServerError),
+	)...)
 }
 
 // NewInvalidError is the building block for errors usually thrown when
 // something fail validation, e.g: "Invalid port". Default status code is `400`.
 //
 // Note: Status code can be redefined, call `SetStatusCode`.
 func NewInvalidError(message string, opts ...Option) error {
-	return New(fmt.Sprintf("invalid %s", message), append(opts, WithStatusCode(http.StatusBadRequest))...)
+	return New(fmt.Sprintf("invalid %s", message), prependOptions(
+		opts,
+		WithStatusCode(http.StatusBadRequest),
+	)...)
 }
 
 // NewMissingError is the building block for errors usually thrown when required
 // information is missing, e.g: "Missing host". Default status code is `400`.
 //
 // Note: Status code can be redefined, call `SetStatusCode`.
 func NewMissingError(message string, opts ...Option) error {
-	return New(fmt.Sprintf("missing %s", message), append(opts, WithStatusCode(http.StatusBadRequest))...)
+	return New(fmt.Sprintf("missing %s", message), prependOptions(
+		opts,
+		WithStatusCode(http.StatusBadRequest),
+	)...)
 }
 
 // NewRequiredError is the building block for errors usually thrown when
@@ -43,5 +52,8 @@ func NewMissingError(message string, opts ...Option) error {
 //
 // Note: Status code can be redefined, call `SetStatusCode`.
 func NewRequiredError(message string, opts ...Option) error {
-	return New(fmt.Sprintf("%s required", message), append(opts, WithStatusCode(http.StatusBadRequest))...)
+	return New(fmt.Sprintf("%s required", message), prependOptions(
+		opts,
+		WithStatusCode(http.StatusBadRequest),
+	)...)
 }

example_test.go

@@ -60,8 +60,8 @@ func ExampleNew() {
 // Demonstrates how to create static, and dynamic custom errors, also how to
 // check, and instrospect custom errors.
 func ExampleNew_options() {
-	fmt.Println(NewMissingError("id", WithCode("E1010"), WithStatusCode(http.StatusOK), WithError(errors.New("some error"))))
+	fmt.Println(NewMissingError("id", WithCode("E1010"), WithStatusCode(http.StatusNotAcceptable), WithError(errors.New("some error"))))
 
 	// output:
-	// E1010: missing id (400 - Bad Request). Original Error: some error
+	// E1010: missing id (406 - Not Acceptable). Original Error: some error
 }

options.go

@@ -16,6 +16,17 @@ package customerror
 // Option allows to define error options.
 type Option func(s *CustomError)
 
+// Prepend options.
+func prependOptions(source []Option, item Option) []Option {
+	source = append(source, nil)
+
+	copy(source[1:], source)
+
+	source[0] = item
+
+	return source
+}
+
 // WithError allows to specify an error which will be wrapped by the custom
 // error.
 func WithError(err error) Option {