validation.ViolationList.AsError - Code Metrics - Inspection of "Merge pull request #27 from muonsoft/template-para..." - muonsoft/validation - Measure and Improve Code Quality continuously with Scrutinizer

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Push — main ( b3a0a2...40c57f )

by Rushan

created 2021-03-17 18:08 UTC

validation.ViolationList.AsError A

↳ Parent: violations.go

Complexity

Conditions

Size

Total Lines	6
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	3
CRAP Score	2

Importance

Changes

Metric	Value
cc	2
eloc	4
dl	0
loc	6
ccs	3
cts	3
cp	1
crap	2
rs	10
c	0
b	0
f	0
nop	0

package validation

import (
	"encoding/json"
	"errors"
	"strings"

	"golang.org/x/text/language"
)

// Violation is the abstraction for validator errors. You can use your own implementations on the application
// side to use it for your needs. In order for the validator to generate application violations,
// it is necessary to implement the ViolationFactory interface and inject it into the validator.
// You can do this by using the SetViolationFactory option in the NewValidator constructor.
type Violation interface {
	error

	// Code is unique, short, and semantic string that can be used to programmatically
	// test for specific violation. All "code" values are defined in the "github.com/muonsoft/validation/code" package
	// and are protected by backward compatibility rules.
	Code() string

	// Is can be used to check that the violation contains one of the specific codes.
	// For an empty list, it should always returns false.
	Is(codes ...string) bool

	// Message is a translated message with injected values from constraint. It can be used to show
	// a description of a violation to the end-user. Possible values for build-in constraints
	// are defined in the "github.com/muonsoft/validation/message" package and can be changed at any time,
	// even in patch versions.
	Message() string

	// MessageTemplate is a template for rendering message. Alongside parameters it can be used to
	// render the message on the client-side of the library.
	MessageTemplate() string

	// Parameters is the map of the template variables and their values provided by the specific constraint.
	Parameters() []TemplateParameter

	// PropertyPath is a path that points to the violated property.
	// See PropertyPath type description for more info.
	PropertyPath() PropertyPath
}

// ViolationFactory is the abstraction that can be used to create custom violations on the application side.
// Use the SetViolationFactory option on the NewValidator constructor to inject your own factory into the validator.
type ViolationFactory interface {
	// CreateViolation creates a new instance of Violation.
	CreateViolation(
		code,
		messageTemplate string,
		pluralCount int,
		parameters []TemplateParameter,
		propertyPath PropertyPath,
		lang language.Tag,
	) Violation
}

// ViolationList is a slice of violations. It is the usual type of error that is returned from a validator.
type ViolationList []Violation

// NewViolationFunc is an adapter that allows you to use ordinary functions as a ViolationFactory.
type NewViolationFunc func(
	code,
	messageTemplate string,
	pluralCount int,
	parameters []TemplateParameter,
	propertyPath PropertyPath,
	lang language.Tag,
) Violation

// CreateViolation creates a new instance of a Violation.
func (f NewViolationFunc) CreateViolation(
	code,
	messageTemplate string,
	pluralCount int,
	parameters []TemplateParameter,
	propertyPath PropertyPath,
	lang language.Tag,
) Violation {
	return f(code, messageTemplate, pluralCount, parameters, propertyPath, lang)
}

// Error returns a formatted list of errors as a string.
func (violations ViolationList) Error() string {
	if len(violations) == 0 {
		return "the list of violations is empty, it looks like you forgot to use the AsError method somewhere"
	}

	var s strings.Builder
	s.Grow(32 * len(violations))

	for i, v := range violations {
		if i > 0 {
			s.WriteString("; ")
		}
		if iv, ok := v.(*internalViolation); ok {
			iv.writeToBuilder(&s)
		} else {
			s.WriteString(v.Error())
		}
	}

	return s.String()
}

// AppendFromError appends a single violation or a slice of violations into the end of a given slice.
// If an error does not implement the Violation or ViolationList interface, it will return an error itself.
// Otherwise nil will be returned.
//
// Example
//  violations := make(ViolationList, 0)
//  err := violations.AppendFromError(previousError)
//  if err != nil {
//      // this error is not a violation, processing must fail
//      return err
//  }
//  // violations contain appended violations from the previousError and can be processed further
func (violations *ViolationList) AppendFromError(err error) error {
	if violation, ok := UnwrapViolation(err); ok {
		*violations = append(*violations, violation)
	} else if violationList, ok := UnwrapViolationList(err); ok {
		*violations = append(*violations, violationList...)
	} else if err != nil {
		return err
	}

	return nil
}

// Has can be used to check that at least one of the violations contains one of the specific codes.
// For an empty list of codes, it should always returns false.
func (violations ViolationList) Has(codes ...string) bool {
	for _, violation := range violations {
		if violation.Is(codes...) {
			return true
		}
	}

	return false
}

// Filter returns a new list of violations with violations of given codes.
func (violations ViolationList) Filter(codes ...string) ViolationList {
	filtered := make(ViolationList, 0, len(violations))

	for _, violation := range violations {
		if violation.Is(codes...) {
			filtered = append(filtered, violation)
		}
	}

	return filtered
}

// AsError converts the list of violations to an error. This method correctly handles cases where
// the list of violations is empty. It returns nil on an empty list, indicating that the validation was successful.
func (violations ViolationList) AsError() error {
	if len(violations) == 0 {
		return nil
	}

	return violations
}

// IsViolation can be used to verify that the error implements the Violation interface.
func IsViolation(err error) bool {
	var violation Violation

	return errors.As(err, &violation)
}

// IsViolationList can be used to verify that the error implements the ViolationList.
func IsViolationList(err error) bool {
	var violations ViolationList

	return errors.As(err, &violations)
}

// UnwrapViolation is a short function to unwrap Violation from the error.
func UnwrapViolation(err error) (Violation, bool) {
	var violation Violation

	as := errors.As(err, &violation)

	return violation, as
}

// UnwrapViolationList is a short function to unwrap ViolationList from the error.
func UnwrapViolationList(err error) (ViolationList, bool) {
	var violations ViolationList

	as := errors.As(err, &violations)

	return violations, as
}

type internalViolation struct {
	code            string
	message         string
	messageTemplate string
	parameters      []TemplateParameter
	propertyPath    PropertyPath
}

func (v internalViolation) Is(codes ...string) bool {
	for _, code := range codes {
		if v.code == code {
			return true
		}
	}

	return false
}

func (v internalViolation) Error() string {
	var s strings.Builder
	s.Grow(32)
	v.writeToBuilder(&s)

	return s.String()
}

func (v internalViolation) writeToBuilder(s *strings.Builder) {
	s.WriteString("violation")
	if len(v.propertyPath) > 0 {
		s.WriteString(" at '" + v.propertyPath.String() + "'")
	}
	s.WriteString(": " + v.message)
}

func (v internalViolation) Code() string {
	return v.code
}

func (v internalViolation) Message() string {
	return v.message
}

func (v internalViolation) MessageTemplate() string {
	return v.messageTemplate
}

func (v internalViolation) Parameters() []TemplateParameter {
	return v.parameters
}

func (v internalViolation) PropertyPath() PropertyPath {
	return v.propertyPath
}

func (v internalViolation) MarshalJSON() ([]byte, error) {
	return json.Marshal(struct {
		Code         string       `json:"code"`
		Message      string       `json:"message"`
		PropertyPath PropertyPath `json:"propertyPath,omitempty"`
	}{
		Code:         v.code,
		Message:      v.message,
		PropertyPath: v.propertyPath,
	})
}

type internalViolationFactory struct {
	translator *Translator
}

func newViolationFactory(translator *Translator) *internalViolationFactory {
	return &internalViolationFactory{translator: translator}
}

func (factory *internalViolationFactory) CreateViolation(
	code,
	messageTemplate string,
	pluralCount int,
	parameters []TemplateParameter,
	propertyPath PropertyPath,
	lang language.Tag,
) Violation {
	message := factory.translator.translate(lang, messageTemplate, pluralCount)

	return &internalViolation{
		code:            code,
		message:         renderMessage(message, parameters),
		messageTemplate: messageTemplate,
		parameters:      parameters,
		propertyPath:    propertyPath,
	}
}

// ViolationBuilder used to build an instance of a Violation.
type ViolationBuilder struct {
	code            string
	messageTemplate string
	pluralCount     int
	parameters      []TemplateParameter
	propertyPath    PropertyPath
	language        language.Tag

	violationFactory ViolationFactory
}

// NewViolationBuilder creates a new ViolationBuilder.
func NewViolationBuilder(factory ViolationFactory) *ViolationBuilder {
	return &ViolationBuilder{violationFactory: factory}
}

// BuildViolation creates a new ViolationBuilder for composing Violation object fluently.
func (b *ViolationBuilder) BuildViolation(code, message string) *ViolationBuilder {
	return &ViolationBuilder{
		code:             code,
		messageTemplate:  message,
		violationFactory: b.violationFactory,
	}
}

// SetParameters sets parameters that can be injected into the violation message.
func (b *ViolationBuilder) SetParameters(parameters []TemplateParameter) *ViolationBuilder {
	b.parameters = parameters

	return b
}

// AddParameter adds one parameter into a slice of parameters.
func (b *ViolationBuilder) AddParameter(name, value string) *ViolationBuilder {
	b.parameters = append(b.parameters, TemplateParameter{Key: name, Value: value})

	return b
}

// SetPropertyPath sets a property path of violated attribute.
func (b *ViolationBuilder) SetPropertyPath(path PropertyPath) *ViolationBuilder {
	b.propertyPath = path

	return b
}

// SetPluralCount sets a plural number that will be used for message pluralization during translations.
func (b *ViolationBuilder) SetPluralCount(pluralCount int) *ViolationBuilder {
	b.pluralCount = pluralCount

	return b
}

// SetLanguage sets language that will be used to translate the violation message.
func (b *ViolationBuilder) SetLanguage(tag language.Tag) *ViolationBuilder {
	b.language = tag

	return b
}

// CreateViolation creates a new violation with given parameters and returns it.
// Violation is created by calling the CreateViolation method of the ViolationFactory.
func (b *ViolationBuilder) CreateViolation() Violation {
	return b.violationFactory.CreateViolation(
		b.code,
		b.messageTemplate,
		b.pluralCount,
		b.parameters,
		b.propertyPath,
		b.language,
	)
}


1		package validation
2
3		import (
4		"encoding/json"
5		"errors"
6		"strings"
7
8		"golang.org/x/text/language"
9		)
10
11		// Violation is the abstraction for validator errors. You can use your own implementations on the application
12		// side to use it for your needs. In order for the validator to generate application violations,
13		// it is necessary to implement the ViolationFactory interface and inject it into the validator.
14		// You can do this by using the SetViolationFactory option in the NewValidator constructor.
15		type Violation interface {
16		error
17
18		// Code is unique, short, and semantic string that can be used to programmatically
19		// test for specific violation. All "code" values are defined in the "github.com/muonsoft/validation/code" package
20		// and are protected by backward compatibility rules.
21		Code() string
22
23		// Is can be used to check that the violation contains one of the specific codes.
24		// For an empty list, it should always returns false.
25		Is(codes ...string) bool
26
27		// Message is a translated message with injected values from constraint. It can be used to show
28		// a description of a violation to the end-user. Possible values for build-in constraints
29		// are defined in the "github.com/muonsoft/validation/message" package and can be changed at any time,
30		// even in patch versions.
31		Message() string
32
33		// MessageTemplate is a template for rendering message. Alongside parameters it can be used to
34		// render the message on the client-side of the library.
35		MessageTemplate() string
36
37		// Parameters is the map of the template variables and their values provided by the specific constraint.
38		Parameters() []TemplateParameter
39
40		// PropertyPath is a path that points to the violated property.
41		// See PropertyPath type description for more info.
42		PropertyPath() PropertyPath
43		}
44
45		// ViolationFactory is the abstraction that can be used to create custom violations on the application side.
46		// Use the SetViolationFactory option on the NewValidator constructor to inject your own factory into the validator.
47		type ViolationFactory interface {
48		// CreateViolation creates a new instance of Violation.
49		CreateViolation(
50		code,
51		messageTemplate string,
52		pluralCount int,
53		parameters []TemplateParameter,
54		propertyPath PropertyPath,
55		lang language.Tag,
56		) Violation
57		}
58
59		// ViolationList is a slice of violations. It is the usual type of error that is returned from a validator.
60		type ViolationList []Violation
61
62		// NewViolationFunc is an adapter that allows you to use ordinary functions as a ViolationFactory.
63		type NewViolationFunc func(
64		code,
65		messageTemplate string,
66		pluralCount int,
67		parameters []TemplateParameter,
68		propertyPath PropertyPath,
69		lang language.Tag,
70		) Violation
71
72		// CreateViolation creates a new instance of a Violation.
73		func (f NewViolationFunc) CreateViolation(
74		code,
75		messageTemplate string,
76		pluralCount int,
77		parameters []TemplateParameter,
78		propertyPath PropertyPath,
79		lang language.Tag,
80		) Violation {
81	1	return f(code, messageTemplate, pluralCount, parameters, propertyPath, lang)
82		}
83
84		// Error returns a formatted list of errors as a string.
85		func (violations ViolationList) Error() string {
86	1	if len(violations) == 0 {
87	1	return "the list of violations is empty, it looks like you forgot to use the AsError method somewhere"
88		}
89
90	1	var s strings.Builder
91	1	s.Grow(32 * len(violations))
92
93	1	for i, v := range violations {
94	1	if i > 0 {
95	1	s.WriteString("; ")
96		}
97	1	if iv, ok := v.(*internalViolation); ok {
98	1	iv.writeToBuilder(&s)
99		} else {
100	1	s.WriteString(v.Error())
101		}
102		}
103
104	1	return s.String()
105		}
106
107		// AppendFromError appends a single violation or a slice of violations into the end of a given slice.
108		// If an error does not implement the Violation or ViolationList interface, it will return an error itself.
109		// Otherwise nil will be returned.
110		//
111		// Example
112		// violations := make(ViolationList, 0)
113		// err := violations.AppendFromError(previousError)
114		// if err != nil {
115		// // this error is not a violation, processing must fail
116		// return err
117		// }
118		// // violations contain appended violations from the previousError and can be processed further
119		func (violations *ViolationList) AppendFromError(err error) error {
120	1	if violation, ok := UnwrapViolation(err); ok {
121	1	violations = append(violations, violation)
122	1	} else if violationList, ok := UnwrapViolationList(err); ok {
123	1	violations = append(violations, violationList...)
124	1	} else if err != nil {
125	1	return err
126		}
127
128	1	return nil
129		}
130
131		// Has can be used to check that at least one of the violations contains one of the specific codes.
132		// For an empty list of codes, it should always returns false.
133		func (violations ViolationList) Has(codes ...string) bool {
134	1	for _, violation := range violations {
135	1	if violation.Is(codes...) {
136	1	return true
137		}
138		}
139
140	1	return false
141		}
142
143		// Filter returns a new list of violations with violations of given codes.
144		func (violations ViolationList) Filter(codes ...string) ViolationList {
145	1	filtered := make(ViolationList, 0, len(violations))
146
147	1	for _, violation := range violations {
148	1	if violation.Is(codes...) {
149	1	filtered = append(filtered, violation)
150		}
151		}
152
153	1	return filtered
154		}
155
156		// AsError converts the list of violations to an error. This method correctly handles cases where
157		// the list of violations is empty. It returns nil on an empty list, indicating that the validation was successful.
158		func (violations ViolationList) AsError() error {
159	1	if len(violations) == 0 {
160	1	return nil
161		}
162
163	1	return violations
164		}
165
166		// IsViolation can be used to verify that the error implements the Violation interface.
167		func IsViolation(err error) bool {
168	1	var violation Violation
169
170	1	return errors.As(err, &violation)
171		}
172
173		// IsViolationList can be used to verify that the error implements the ViolationList.
174		func IsViolationList(err error) bool {
175	1	var violations ViolationList
176
177	1	return errors.As(err, &violations)
178		}
179
180		// UnwrapViolation is a short function to unwrap Violation from the error.
181		func UnwrapViolation(err error) (Violation, bool) {
182	1	var violation Violation
183
184	1	as := errors.As(err, &violation)
185
186	1	return violation, as
187		}
188
189		// UnwrapViolationList is a short function to unwrap ViolationList from the error.
190		func UnwrapViolationList(err error) (ViolationList, bool) {
191	1	var violations ViolationList
192
193	1	as := errors.As(err, &violations)
194
195	1	return violations, as
196		}
197
198		type internalViolation struct {
199		code string
200		message string
201		messageTemplate string
202		parameters []TemplateParameter
203		propertyPath PropertyPath
204		}
205
206		func (v internalViolation) Is(codes ...string) bool {
207	1	for _, code := range codes {
208	1	if v.code == code {
209	1	return true
210		}
211		}
212
213	1	return false
214		}
215
216		func (v internalViolation) Error() string {
217	1	var s strings.Builder
218	1	s.Grow(32)
219	1	v.writeToBuilder(&s)
220
221	1	return s.String()
222		}
223
224		func (v internalViolation) writeToBuilder(s *strings.Builder) {
225	1	s.WriteString("violation")
226	1	if len(v.propertyPath) > 0 {
227	1	s.WriteString(" at '" + v.propertyPath.String() + "'")
228		}
229	1	s.WriteString(": " + v.message)
230		}
231
232		func (v internalViolation) Code() string {
233	1	return v.code
234		}
235
236		func (v internalViolation) Message() string {
237	1	return v.message
238		}
239
240		func (v internalViolation) MessageTemplate() string {
241		return v.messageTemplate
242		}
243
244		func (v internalViolation) Parameters() []TemplateParameter {
245		return v.parameters
246		}
247
248		func (v internalViolation) PropertyPath() PropertyPath {
249	1	return v.propertyPath
250		}
251
252		func (v internalViolation) MarshalJSON() ([]byte, error) {
253	1	return json.Marshal(struct {
254		Code string `json:"code"`
255		Message string `json:"message"`
256		PropertyPath PropertyPath `json:"propertyPath,omitempty"`
257		}{
258		Code: v.code,
259		Message: v.message,
260		PropertyPath: v.propertyPath,
261		})
262		}
263
264		type internalViolationFactory struct {
265		translator *Translator
266		}
267
268		func newViolationFactory(translator Translator) internalViolationFactory {
269	1	return &internalViolationFactory{translator: translator}
270		}
271
272		func (factory *internalViolationFactory) CreateViolation(
273		code,
274		messageTemplate string,
275		pluralCount int,
276		parameters []TemplateParameter,
277		propertyPath PropertyPath,
278		lang language.Tag,
279		) Violation {
280	1	message := factory.translator.translate(lang, messageTemplate, pluralCount)
281
282	1	return &internalViolation{
283		code: code,
284		message: renderMessage(message, parameters),
285		messageTemplate: messageTemplate,
286		parameters: parameters,
287		propertyPath: propertyPath,
288		}
289		}
290
291		// ViolationBuilder used to build an instance of a Violation.
292		type ViolationBuilder struct {
293		code string
294		messageTemplate string
295		pluralCount int
296		parameters []TemplateParameter
297		propertyPath PropertyPath
298		language language.Tag
299
300		violationFactory ViolationFactory
301		}
302
303		// NewViolationBuilder creates a new ViolationBuilder.
304		func NewViolationBuilder(factory ViolationFactory) *ViolationBuilder {
305	1	return &ViolationBuilder{violationFactory: factory}
306		}
307
308		// BuildViolation creates a new ViolationBuilder for composing Violation object fluently.
309		func (b ViolationBuilder) BuildViolation(code, message string) ViolationBuilder {
310	1	return &ViolationBuilder{
311		code: code,
312		messageTemplate: message,
313		violationFactory: b.violationFactory,
314		}
315		}
316
317		// SetParameters sets parameters that can be injected into the violation message.
318		func (b ViolationBuilder) SetParameters(parameters []TemplateParameter) ViolationBuilder {
319	1	b.parameters = parameters
320
321	1	return b
322		}
323
324		// AddParameter adds one parameter into a slice of parameters.
325		func (b ViolationBuilder) AddParameter(name, value string) ViolationBuilder {
326	1	b.parameters = append(b.parameters, TemplateParameter{Key: name, Value: value})
327
328	1	return b
329		}
330
331		// SetPropertyPath sets a property path of violated attribute.
332		func (b ViolationBuilder) SetPropertyPath(path PropertyPath) ViolationBuilder {
333	1	b.propertyPath = path
334
335	1	return b
336		}
337
338		// SetPluralCount sets a plural number that will be used for message pluralization during translations.
339		func (b ViolationBuilder) SetPluralCount(pluralCount int) ViolationBuilder {
340	1	b.pluralCount = pluralCount
341
342	1	return b
343		}
344
345		// SetLanguage sets language that will be used to translate the violation message.
346		func (b ViolationBuilder) SetLanguage(tag language.Tag) ViolationBuilder {
347	1	b.language = tag
348
349	1	return b
350		}
351
352		// CreateViolation creates a new violation with given parameters and returns it.
353		// Violation is created by calling the CreateViolation method of the ViolationFactory.
354		func (b *ViolationBuilder) CreateViolation() Violation {
355	1	return b.violationFactory.CreateViolation(
356		b.code,
357		b.messageTemplate,
358		b.pluralCount,
359		b.parameters,
360		b.propertyPath,
361		b.language,
362		)
363		}
364

muonsoft / validation

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validation.ViolationList.AsError A

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