feat: implement marshallable schema (#33)

* feat: implement MarshalJson method for fields

* test: add tests for marshalling schema json

* docs: update readme

README.md

@@ -135,6 +135,8 @@ func main() {
 
 `schema` object contains a string field, named `name`. This code validates `jsonString`.
 
+> **Note**: You could Marshal your schema as a json object for backup usages with `json.Marshal` function.
+
 # Fields
 
 ## Integer

array.go

@@ -1,6 +1,7 @@
 package vjson
 
 import (
+	"encoding/json"
 	"github.com/hashicorp/go-multierror"
 	"github.com/pkg/errors"
 )
@@ -82,6 +83,27 @@ func (a *ArrayField) MaxLength(length int) *ArrayField {
 	return a
 }
 
+func (a *ArrayField) MarshalJSON() ([]byte, error) {
+	itemsRaw, err := json.Marshal(a.items)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not marshal items field of array field: %s", a.name)
+	}
+
+	items := make(map[string]interface{})
+	err = json.Unmarshal(itemsRaw, &items)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not unmarshal items field of array field: %s", a.name)
+	}
+	return json.Marshal(ArrayFieldSpec{
+		Name:      a.name,
+		Type:      arrayType,
+		Required:  a.required,
+		Items:     items,
+		MinLength: a.minLength,
+		MaxLength: a.maxLength,
+	})
+}
+
 // Array is the constructor of an array field.
 func Array(name string, itemField Field) *ArrayField {
 	return &ArrayField{

array_spec.go

@@ -2,11 +2,12 @@ package vjson
 
 // ArrayFieldSpec is a type used for parsing an ArrayField
 type ArrayFieldSpec struct {
-	Name      string                 `mapstructure:"name"`
-	Required  bool                   `mapstructure:"required"`
-	Items     map[string]interface{} `mapstructure:"items"`
-	MinLength int                    `mapstructure:"min_length"`
-	MaxLength int                    `mapstructure:"max_length"`
+	Name      string                 `mapstructure:"name" json:"name"`
+	Type      fieldType              `json:"type"`
+	Required  bool                   `mapstructure:"required" json:"required,omitempty"`
+	Items     map[string]interface{} `mapstructure:"items" json:"items,omitempty"`
+	MinLength int                    `mapstructure:"min_length" json:"minLength,omitempty"`
+	MaxLength int                    `mapstructure:"max_length" json:"maxLength,omitempty"`
 }
 
 // NewArray receives an ArrayFieldSpec and returns and ArrayField

array_test.go

@@ -1,6 +1,7 @@
 package vjson
 
 import (
+	"encoding/json"
 	"github.com/stretchr/testify/assert"
 	"testing"
 )
@@ -96,6 +97,21 @@ func TestArrayField_Validate(t *testing.T) {
 	})
 }
 
+func TestArrayField_MarshalJSON(t *testing.T) {
+	field := Array("foo", String("bar"))
+
+	b, err := json.Marshal(field)
+	assert.Nil(t, err)
+
+	data := map[string]interface{}{}
+	err = json.Unmarshal(b, &data)
+	assert.Nil(t, err)
+
+	assert.Equal(t, "foo", data["name"])
+	assert.Equal(t, string(arrayType), data["type"])
+	assert.Equal(t, "bar", data["items"].(map[string]interface{})["name"])
+}
+
 func TestNewArray(t *testing.T) {
 	field := NewArray(ArrayFieldSpec{
 		Name:     "bar",

boolean.go

@@ -1,6 +1,9 @@
 package vjson
 
-import "github.com/pkg/errors"
+import (
+	"encoding/json"
+	"github.com/pkg/errors"
+)
 
 // BooleanField is the type for validating booleans in a JSON
 type BooleanField struct {
@@ -55,6 +58,15 @@ func (b *BooleanField) ShouldBe(value bool) *BooleanField {
 	return b
 }
 
+func (b *BooleanField) MarshalJSON() ([]byte, error) {
+	return json.Marshal(BooleanFieldSpec{
+		Name:     b.name,
+		Type:     booleanType,
+		Required: b.required,
+		Value:    b.value,
+	})
+}
+
 // Boolean is the constructor of a boolean field
 func Boolean(name string) *BooleanField {
 	return &BooleanField{

boolean_spec.go

@@ -2,9 +2,10 @@ package vjson
 
 // BooleanFieldSpec is a type used for parsing an BooleanField
 type BooleanFieldSpec struct {
-	Name     string `mapstructure:"name"`
-	Required bool   `mapstructure:"required"`
-	Value    bool   `mapstructure:"value"`
+	Name     string    `mapstructure:"name" json:"name"`
+	Type     fieldType `json:"type"`
+	Required bool      `mapstructure:"required" json:"required,omitempty"`
+	Value    bool      `mapstructure:"value" json:"value,omitempty"`
 }
 
 // NewBoolean receives an BooleanFieldSpec and returns and BooleanField

boolean_test.go

@@ -1,6 +1,7 @@
 package vjson
 
 import (
+	"encoding/json"
 	"github.com/stretchr/testify/assert"
 	"testing"
 )
@@ -55,6 +56,20 @@ func TestBooleanField_Validate(t *testing.T) {
 	})
 }
 
+func TestBooleanField_MarshalJSON(t *testing.T) {
+	field := Boolean("foo")
+
+	b, err := json.Marshal(field)
+	assert.Nil(t, err)
+
+	data := map[string]string{}
+	err = json.Unmarshal(b, &data)
+	assert.Nil(t, err)
+
+	assert.Equal(t, "foo", data["name"])
+	assert.Equal(t, string(booleanType), data["type"])
+}
+
 func TestNewBoolean(t *testing.T) {
 	field := NewBoolean(BooleanFieldSpec{
 		Name:     "bar",

field.go

@@ -1,8 +1,11 @@
 package vjson
 
+import "encoding/json"
+
 // Field is the abstraction on a field in a json.
 // different field types can be implemented with implementing this interface.
 type Field interface {
+	json.Marshaler
 	GetName() string
 	Validate(interface{}) error
 }

float.go

@@ -1,6 +1,7 @@
 package vjson
 
 import (
+	"encoding/json"
 	"fmt"
 	"github.com/hashicorp/go-multierror"
 	"github.com/pkg/errors"
@@ -138,6 +139,25 @@ func (f *FloatField) Range(start, end float64) *FloatField {
 	return f
 }
 
+func (f *FloatField) MarshalJSON() ([]byte, error) {
+	ranges := make([]FloatRangeSpec, 0, len(f.ranges))
+	for _, r := range f.ranges {
+		ranges = append(ranges, FloatRangeSpec{
+			Start: r.start,
+			End:   r.end,
+		})
+	}
+	return json.Marshal(FloatFieldSpec{
+		Name:     f.name,
+		Type:     floatType,
+		Required: f.required,
+		Min:      f.min,
+		Max:      f.max,
+		Positive: f.positive,
+		Ranges:   ranges,
+	})
+}
+
 // Float is the constructor of a float field
 func Float(name string) *FloatField {
 	return &FloatField{

float_spec.go

@@ -2,18 +2,19 @@ package vjson
 
 // FloatRangeSpec is a type for parsing a float field range
 type FloatRangeSpec struct {
-	Start float64 `mapstructure:"start"`
-	End   float64 `mapstructure:"end"`
+	Start float64 `mapstructure:"start" json:"start"`
+	End   float64 `mapstructure:"end" json:"end"`
 }
 
 // FloatFieldSpec is a type used for parsing an FloatField
 type FloatFieldSpec struct {
-	Name     string           `mapstructure:"name"`
-	Required bool             `mapstructure:"required"`
-	Min      float64          `mapstructure:"min"`
-	Max      float64          `mapstructure:"max"`
-	Positive bool             `mapstructure:"positive"`
-	Ranges   []FloatRangeSpec `mapstructure:"ranges"`
+	Name     string           `mapstructure:"name" json:"name"`
+	Type     fieldType        `json:"type"`
+	Required bool             `mapstructure:"required" json:"required,omitempty"`
+	Min      float64          `mapstructure:"min" json:"min,omitempty"`
+	Max      float64          `mapstructure:"max" json:"max,omitempty"`
+	Positive bool             `mapstructure:"positive" json:"positive,omitempty"`
+	Ranges   []FloatRangeSpec `mapstructure:"ranges" json:"ranges,omitempty"`
 }
 
 // NewFloat receives an FloatFieldSpec and returns and FloatField

float_test.go

@@ -1,6 +1,7 @@
 package vjson
 
 import (
+	"encoding/json"
 	"github.com/stretchr/testify/assert"
 	"testing"
 )
@@ -94,6 +95,21 @@ func TestFloatField_Validate(t *testing.T) {
 	})
 }
 
+func TestFloatField_MarshalJSON(t *testing.T) {
+	field := Float("foo").Range(10, 20)
+	b, err := json.Marshal(field)
+	assert.Nil(t, err)
+
+	data := map[string]interface{}{}
+	err = json.Unmarshal(b, &data)
+	assert.Nil(t, err)
+
+	assert.Equal(t, "foo", data["name"])
+	assert.Equal(t, string(floatType), data["type"])
+	assert.Equal(t, float64(10), data["ranges"].([]interface{})[0].(map[string]interface{})["start"])
+	assert.Equal(t, float64(20), data["ranges"].([]interface{})[0].(map[string]interface{})["end"])
+}
+
 func TestNewFloat(t *testing.T) {
 	field := NewFloat(FloatFieldSpec{
 		Name:     "bar",

go.mod

@@ -1,6 +1,6 @@
 module github.com/miladibra10/vjson
 
-go 1.15
+go 1.17
 
 require (
 	github.com/hashicorp/go-multierror v1.1.1
@@ -9,3 +9,12 @@ require (
 	github.com/stretchr/testify v1.7.0
 	github.com/tidwall/gjson v1.7.5
 )
+
+require (
+	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/hashicorp/errwrap v1.0.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/tidwall/match v1.0.3 // indirect
+	github.com/tidwall/pretty v1.1.0 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
+)

integer.go

@@ -1,6 +1,7 @@
 package vjson
 
 import (
+	"encoding/json"
 	"fmt"
 	"github.com/hashicorp/go-multierror"
 	"github.com/pkg/errors"
@@ -147,6 +148,25 @@ func (i *IntegerField) Range(start, end int) *IntegerField {
 	return i
 }
 
+func (i *IntegerField) MarshalJSON() ([]byte, error) {
+	ranges := make([]IntRangeSpec, 0, len(i.ranges))
+	for _, r := range i.ranges {
+		ranges = append(ranges, IntRangeSpec{
+			Start: r.start,
+			End:   r.end,
+		})
+	}
+	return json.Marshal(IntegerFieldSpec{
+		Name:     i.name,
+		Required: i.required,
+		Min:      i.min,
+		Max:      i.max,
+		Positive: i.positive,
+		Ranges:   ranges,
+		Type:     integerType,
+	})
+}
+
 // Integer is the constructor of an integer field
 func Integer(name string) *IntegerField {
 	return &IntegerField{

integer_spec.go

@@ -2,18 +2,19 @@ package vjson
 
 // IntRangeSpec is a type for parsing an integer field range
 type IntRangeSpec struct {
-	Start int `mapstructure:"start"`
-	End   int `mapstructure:"end"`
+	Start int `mapstructure:"start" json:"start"`
+	End   int `mapstructure:"end" json:"end"`
 }
 
 // IntegerFieldSpec is a type used for parsing an IntegerField
 type IntegerFieldSpec struct {
-	Name     string         `mapstructure:"name"`
-	Required bool           `mapstructure:"required"`
-	Min      int            `mapstructure:"min"`
-	Max      int            `mapstructure:"max"`
-	Positive bool           `mapstructure:"positive"`
-	Ranges   []IntRangeSpec `mapstructure:"ranges"`
+	Name     string         `mapstructure:"name" json:"name"`
+	Type     fieldType      `json:"type"`
+	Required bool           `mapstructure:"required" json:"required,omitempty"`
+	Min      int            `mapstructure:"min" json:"min,omitempty"`
+	Max      int            `mapstructure:"max" json:"max,omitempty"`
+	Positive bool           `mapstructure:"positive" json:"positive,omitempty"`
+	Ranges   []IntRangeSpec `mapstructure:"ranges" json:"ranges,omitempty"`
 }
 
 // NewInteger receives an IntegerFieldSpec and returns and IntegerField

integer_test.go

@@ -1,6 +1,7 @@
 package vjson
 
 import (
+	"encoding/json"
 	"github.com/stretchr/testify/assert"
 	"testing"
 )
@@ -120,6 +121,21 @@ func TestIntegerField_Validate(t *testing.T) {
 	})
 }
 
+func TestIntegerField_MarshalJSON(t *testing.T) {
+	field := Integer("foo").Range(10, 20)
+	b, err := json.Marshal(field)
+	assert.Nil(t, err)
+
+	data := map[string]interface{}{}
+	err = json.Unmarshal(b, &data)
+	assert.Nil(t, err)
+
+	assert.Equal(t, "foo", data["name"])
+	assert.Equal(t, string(integerType), data["type"])
+	assert.Equal(t, float64(10), data["ranges"].([]interface{})[0].(map[string]interface{})["start"])
+	assert.Equal(t, float64(20), data["ranges"].([]interface{})[0].(map[string]interface{})["end"])
+}
+
 func TestNewInteger(t *testing.T) {
 	field := NewInteger(IntegerFieldSpec{
 		Name:     "bar",