v1.0.0

.github/workflows/go.yml

@@ -16,15 +16,15 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.15
+          go-version: 1.17
 
       - name: Setup golangci-lint
         uses: golangci/golangci-lint-action@v2.5.2
         with:
-          version: v1.41.1
+          version: v1.43.0
 
       - name: Lint
-        run: /home/runner/golangci-lint-1.41.1-linux-amd64/golangci-lint run -v -c .golangci.yml
+        run: /home/runner/golangci-lint-1.43.0-linux-amd64/golangci-lint run -v -c .golangci.yml
 
       - name: Test
         run: make test coverage

.golangci.yml

@@ -19,6 +19,7 @@ linters:
     - cyclop
     - tagliatelle
     - goerr113
+    - varnamelen
   fast: false
 
 # Settings for specific linters

CHANGELOG.md

@@ -7,16 +7,22 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Roadmap
 
-## [0.0.2] - 2021-09-27
+## [1.0.0] - 2022-02-17
+### Added
+- Functional `Option`s.
 
 ### Changed
+- `New` now implements the functional optional pattern.
 
+### Removed
+- Removed `SetStatusCode`.
+
+## [0.0.2] - 2021-09-27
+### Changed
 - `Wrap` now accepts a list of errors.
 
 ## [0.0.1] - 2021-09-24
-
 ### Checklist
-
 - [x] CI Pipeline:
   - [x] Lint
   - [x] Tests
@@ -39,7 +45,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - [x] Example's test file
 
 ### Added
-
 - [x] Ability to create custom errors.
 - [x] Ability to create custom errors with code.
 - [x] Ability to create custom errors with status code.

builtin.go

@@ -17,31 +17,31 @@ import (
 // action failed, e.g: "Failed to create host". Default status code is `500`.
 //
 // Note: Status code can be redefined, call `SetStatusCode`.
-func NewFailedToError(message string, code string, err error) error {
-	return New(fmt.Sprintf("failed to %s", message), code, http.StatusInternalServerError, err)
+func NewFailedToError(message string, opts ...Option) error {
+	return New(fmt.Sprintf("failed to %s", message), append(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, code string, err error) error {
-	return New(fmt.Sprintf("invalid %s", message), code, http.StatusBadRequest, err)
+func NewInvalidError(message string, opts ...Option) error {
+	return New(fmt.Sprintf("invalid %s", message), append(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, code string, err error) error {
-	return New(fmt.Sprintf("missing %s", message), code, http.StatusBadRequest, err)
+func NewMissingError(message string, opts ...Option) error {
+	return New(fmt.Sprintf("missing %s", message), append(opts, WithStatusCode(http.StatusBadRequest))...)
 }
 
 // NewRequiredError is the building block for errors usually thrown when
 // required information is missing, e.g: "Port is required". Default status code
 // is `400`.
 //
 // Note: Status code can be redefined, call `SetStatusCode`.
-func NewRequiredError(message string, code string, err error) error {
-	return New(fmt.Sprintf("%s required", message), code, http.StatusBadRequest, err)
+func NewRequiredError(message string, opts ...Option) error {
+	return New(fmt.Sprintf("%s required", message), append(opts, WithStatusCode(http.StatusBadRequest))...)
 }

customerror.go

@@ -34,16 +34,6 @@ type CustomError struct {
 // Error interface implementation.
 //////
 
-// SetStatusCode sets the status code.
-//
-// Note: Calling this on a static error is dangerous as it will change the
-// status code of all its references!
-func (cE *CustomError) SetStatusCode(code int) *CustomError {
-	cE.StatusCode = code
-
-	return cE
-}
-
 // Error interface implementation returns the properly formatted error message.
 func (cE *CustomError) Error() string {
 	errMsg := cE.Message
@@ -68,6 +58,13 @@ func (cE *CustomError) Unwrap() error {
 	return cE.Err
 }
 
+// Is interface implementation ensures chain continuity. Treats `CustomError` as
+// equivalent to `err`.
+//nolint:errorlint
+func (cE CustomError) Is(err error) bool {
+	return cE.Err == err
+}
+
 // Wrap `customError` around `errors`.
 func Wrap(customError error, errors ...error) error {
 	errMsgs := []string{}
@@ -85,14 +82,14 @@ func Wrap(customError error, errors ...error) error {
 // Factory.
 //////
 
-// New creates custom errors. `message` is required. Failing to satisfy that
-// will throw a fatal error.
-func New(message, code string, statusCode int, err error) *CustomError {
+// New is the custom error factory.
+func New(message string, opts ...Option) error {
 	cE := &CustomError{
-		Code:       code,
-		Message:    message,
-		Err:        err,
-		StatusCode: statusCode,
+		Message: message,
+	}
+
+	for _, opt := range opts {
+		opt(cE)
 	}
 
 	if err := validator.New().Struct(cE); err != nil {

customerror_test.go

@@ -25,12 +25,10 @@ var (
 )
 
 //nolint:lll
-func TestNew(t *testing.T) {
+func TestNewLowLevel(t *testing.T) {
 	type args struct {
-		message    string
-		code       string
-		statusCode int
-		err        error
+		message string
+		opts    []Option
 	}
 	tests := []struct {
 		name string
@@ -46,79 +44,75 @@ func TestNew(t *testing.T) {
 			name: "should work - with message, and code",
 			args: args{
 				message: failedCreateSomethingMsg,
-				code:    code,
+				opts:    []Option{WithCode(code)},
 			},
 			want: "E1010: Failed to create something",
 		},
 		{
 			name: "should work - with message, and error",
 			args: args{
 				message: failedCreateSomethingMsg,
-				err:     ErrFailedToReachServer,
+				opts:    []Option{WithError(ErrFailedToReachServer)},
 			},
 			want: "Failed to create something. Original Error: Failed to reach servers",
 		},
 		{
 			name: "should work - with message, and deep error",
 			args: args{
 				message: failedCreateSomethingMsg,
-				err:     ErrFailedToReachServerDeep,
+				opts:    []Option{WithError(ErrFailedToReachServerDeep)},
 			},
 			want: "Failed to create something. Original Error: Failed to reach servers. Servers are broken",
 		},
 		{
 			name: "should work - with message, and status code",
 			args: args{
-				message:    failedCreateSomethingMsg,
-				statusCode: statusCode,
+				message: failedCreateSomethingMsg,
+				opts:    []Option{WithStatusCode(statusCode)},
 			},
 			want: "Failed to create something (404 - Not Found)",
 		},
 		{
 			name: "should work - with message, code, and error",
 			args: args{
 				message: failedCreateSomethingMsg,
-				code:    code,
-				err:     ErrFailedToReachServer,
+				opts:    []Option{WithCode(code), WithError(ErrFailedToReachServer)},
 			},
 			want: "E1010: Failed to create something. Original Error: Failed to reach servers",
 		},
 		{
 			name: "should work - with message, code, error, and deep error",
 			args: args{
 				message: failedCreateSomethingMsg,
-				code:    code,
-				err:     ErrFailedToReachServerDeep,
+				opts:    []Option{WithCode(code), WithError(ErrFailedToReachServerDeep)},
 			},
 			want: "E1010: Failed to create something. Original Error: Failed to reach servers. Servers are broken",
 		},
 		{
 			name: "should work - with message, code, error, deep error, and status code",
 			args: args{
-				message:    failedCreateSomethingMsg,
-				code:       code,
-				statusCode: statusCode,
-				err:        ErrFailedToReachServerDeep,
+				message: failedCreateSomethingMsg,
+				opts:    []Option{WithCode(code), WithError(ErrFailedToReachServerDeep), WithStatusCode(statusCode)},
 			},
 			want: "E1010: Failed to create something (404 - Not Found). Original Error: Failed to reach servers. Servers are broken",
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := New(tt.args.message, tt.args.code, tt.args.statusCode, tt.args.err)
+			got := New(tt.args.message, tt.args.opts...)
 
 			if !strings.EqualFold(got.Error(), tt.want) {
-				t.Errorf("New() = %v, want %v", got, tt.want)
+				t.Errorf("NewLowLevel() = %v, want %v", got, tt.want)
 			}
 		})
 	}
 }
 
 func TestBuiltin(t *testing.T) {
-	ErrFailedToCreateFile := NewFailedToError("create file", "", nil)
-	ErrInvalidPath := NewInvalidError("path", "", nil)
-	ErrMissingPath := NewMissingError("path", "", nil)
-	ErrRequiredPath := NewRequiredError("path is", "", nil)
+	ErrFailedToCreateFile := NewFailedToError("create file")
+	ErrInvalidPath := NewInvalidError("path")
+	ErrMissingPath := NewMissingError("path")
+	ErrRequiredPath := NewRequiredError("path is")
 
 	testFunc := func(e error) error { return e }
 
@@ -246,7 +240,7 @@ func TestNew_deepNestedErrors(t *testing.T) {
 
 	layer3 := fmt.Errorf("layer 3. %w", layer2)
 
-	ErrLayered := New("custom message", "", 0, layer3)
+	ErrLayered := New("custom message", WithError(layer3))
 	if ErrLayered.Error() != expectedErrMsg {
 		t.Errorf("CustomError deep nested errors got %s, want %s", ErrLayered, expectedErrMsg)
 	}
@@ -284,7 +278,7 @@ func TestWrap(t *testing.T) {
 
 	layer3 := fmt.Errorf("layer 3. %w", layer2)
 
-	ErrLayered := New("custom message", "", 0, layer3)
+	ErrLayered := New("custom message", WithError(layer3))
 	if ErrLayered.Error() != expectedErrMsg {
 		t.Errorf("Wrap got %s, want %s", ErrLayered, expectedErrMsg)
 	}
@@ -303,48 +297,3 @@ func TestWrap(t *testing.T) {
 		t.Errorf("Wrap Is got %s, want %s", errSome, ErrLayered)
 	}
 }
-
-func TestCustomError_SetStatusCode(t *testing.T) {
-	type fields struct {
-		Code       string
-		Err        error
-		Message    string
-		StatusCode int
-	}
-	type args struct {
-		code int
-	}
-	tests := []struct {
-		name   string
-		fields fields
-		args   args
-		want   *CustomError
-	}{
-		{
-			name: "Should work",
-			fields: fields{
-				Code:       "",
-				Err:        nil,
-				Message:    "test",
-				StatusCode: 0,
-			},
-			args: args{
-				code: 400,
-			},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			cE := New(
-				tt.fields.Message,
-				tt.fields.Code,
-				tt.fields.StatusCode,
-				tt.fields.Err,
-			).SetStatusCode(tt.args.code)
-
-			if cE.StatusCode != tt.args.code {
-				t.Errorf("CustomError.SetStatusCode() = %v, want %v", cE.StatusCode, tt.args.code)
-			}
-		})
-	}
-}

example_test.go

@@ -7,13 +7,14 @@ package customerror
 import (
 	"errors"
 	"fmt"
+	"net/http"
 )
 
 // Demonstrates how to create static, and dynamic custom errors, also how to
 // check, and instrospect custom errors.
 func ExampleNew() {
 	// Custom static error definition.
-	ErrMissingID := NewMissingError("id", "E1010", nil)
+	ErrMissingID := NewMissingError("id", WithCode("E1010"))
 
 	// Some function, for demo purpose.
 	SomeFunc := func(id string) error {
@@ -23,7 +24,7 @@ func ExampleNew() {
 		}
 
 		// Dynamic custom error.
-		return NewFailedToError("write to disk", "E1523", nil)
+		return NewFailedToError("write to disk", WithCode("E1523"))
 	}
 
 	// Case: Without `id`, returns `ErrMissingID`.
@@ -55,3 +56,12 @@ func ExampleNew() {
 	// 500
 	// E1523: failed to write to disk (500 - Internal Server Error)
 }
+
+// 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"))))
+
+	// output:
+	// E1010: missing id (400 - Bad Request). Original Error: some error
+}

go.mod

@@ -2,7 +2,7 @@ module github.com/saucelabs/customerror
 
 go 1.17
 
-require github.com/go-playground/validator/v10 v10.9.0
+require github.com/go-playground/validator/v10 v10.10.0
 
 require (
 	github.com/go-playground/locales v0.14.0 // indirect

go.sum

@@ -8,8 +8,8 @@ github.com/go-playground/locales v0.14.0 h1:u50s323jtVGugKlcYeyzC0etD1HifMjqmJqb
 github.com/go-playground/locales v0.14.0/go.mod h1:sawfccIbzZTqEDETgFXqTho0QybSa7l++s0DH+LDiLs=
 github.com/go-playground/universal-translator v0.18.0 h1:82dyy6p4OuJq4/CByFNOn/jYrnRPArHwAcmLoJZxyho=
 github.com/go-playground/universal-translator v0.18.0/go.mod h1:UvRDBj+xPUEGrFYl+lu/H90nyDXpg0fqeB/AQUGNTVA=
-github.com/go-playground/validator/v10 v10.9.0 h1:NgTtmN58D0m8+UuxtYmGztBJB7VnPgjj221I1QHci2A=
-github.com/go-playground/validator/v10 v10.9.0/go.mod h1:74x4gJWsvQexRdW8Pn3dXSGrTK4nAUsbPlLADvpJkos=
+github.com/go-playground/validator/v10 v10.10.0 h1:I7mrTYv78z8k8VXa/qJlOlEXn/nBh+BF8dHX5nt/dr0=
+github.com/go-playground/validator/v10 v10.10.0/go.mod h1:74x4gJWsvQexRdW8Pn3dXSGrTK4nAUsbPlLADvpJkos=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=