verax

package main

import (
	"fmt"

	"github.com/ctx42/verax/pkg/spec"
	"github.com/ctx42/verax/pkg/verax"
)

// nonEmptyWord is a custom RuleFunc used in ExampleBuilders_by.
// Declared as verax.RuleFunc so the type assertion in ByRuleFromSpec succeeds.
var nonEmptyWord verax.RuleFunc = func(v any) error {
	str, err := verax.EnsureString(v)
	if err != nil {
		return verax.ErrInvType
	}
	if len(str) < 3 {
		return verax.NewError("must be at least 3 characters long", "ECShort")
	}
	return nil
}

func main() {
	// Register the function as a named source so it survives serialization.
	src, _ := spec.NewSource("nonEmptyWord", nonEmptyWord)

	reg := spec.NewRegistry[verax.Rule]()
	reg.RegisterBuilders(verax.Builders())
	reg.RegisterSource(src)

	// Encode.
	rule := verax.By(nonEmptyWord)
	spc, _ := rule.Spec()
	data, _ := reg.EncodeSpec(spc)

	// Decode and rebuild — the function is resolved by name from the registry.
	restored, _ := reg.DecodeAndBuild(data)

	err := verax.Validate("hi", restored)
	fmt.Println(err)
}

Output:
must be at least 3 characters long

package main

import (
	"fmt"

	"github.com/ctx42/verax/pkg/spec"
	"github.com/ctx42/verax/pkg/verax"
)

func main() {
	data := []byte(`{"name":"range-rule","args":{"mode":{"type":"string","value":"min"},"value":{"type":"int","value":18}}}`)

	reg := spec.NewRegistry[verax.Rule]()
	reg.RegisterBuilders(verax.Builders())

	restored, _ := reg.DecodeAndBuild(data)

	err := verax.Validate(15, restored)
	fmt.Println(err)
}

Output:
must be greater or equal to 18

package main

import (
	"fmt"

	"github.com/ctx42/verax/pkg/spec"
	"github.com/ctx42/verax/pkg/verax"
)

func main() {
	rule := verax.Min(18)

	reg := spec.NewRegistry[verax.Rule]()
	reg.RegisterBuilders(verax.Builders())

	spc, _ := rule.Spec()
	data, _ := reg.EncodeSpec(spc)

	fmt.Println(string(data))
}

Output:
{"name":"range-rule","args":{"mode":"min","value":{"type":"int","value":18}}}

package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/ctx42/verax/pkg/verax"
)

type Planet struct {
	Position int    `json:"position"`
	Name     string `json:"name" solar:"planet_name"`
	Life     float64
}

func (p *Planet) Validate() error {
	return verax.ValidateStruct(
		p,
		verax.Field(&p.Position, verax.Min(1), verax.Max(8)),
		verax.Field(&p.Name, verax.Length(4, 7)).Tag("solar"),
		verax.Field(&p.Life, verax.Min(0.0), verax.Max(1.0)),
	)
}

func main() {
	planets := map[string]*Planet{
		"mer": {1, "Mer", 0},
		"ear": {3, "Earth", 1.0},
		"x":   {9, "X", 0.1},
	}

	err := verax.Validate(planets)

	PrintError(err)
	PrintJSON(err)
}

// PrintJSON marshals value to JSON string.
func PrintJSON(v any) {
	data, err := json.MarshalIndent(v, "", "    ")
	if err != nil {
		panic(err)
	}
	fmt.Printf("JSON:\n%s\n", string(data))
}

// PrintError formats error message.
func PrintError(err error) {
	var msg strings.Builder
	for line := range strings.SplitSeq(err.Error(), "; ") {
		msg.WriteString("- " + line + "\n")
	}
	fmt.Printf("ERROR:\n\n%s\n", msg.String())
}

Output:
ERROR:

- mer.planet_name: the length must be between 4 and 7
- x.planet_name: the length must be between 4 and 7
- x.position: must be less or equal to 8

JSON:
{
    "mer.planet_name": {
        "code": "ECInvLength",
        "error": "the length must be between 4 and 7"
    },
    "x.planet_name": {
        "code": "ECInvLength",
        "error": "the length must be between 4 and 7"
    },
    "x.position": {
        "code": "ECInvRange",
        "error": "must be less or equal to 8"
    }
}

package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/ctx42/verax/pkg/verax"
)

func main() {
	err := verax.Validate(
		45,
		verax.Required,
		verax.Min(42),
		verax.Max(44),
	)

	PrintError(err)
	PrintJSON(err)
}

// PrintJSON marshals value to JSON string.
func PrintJSON(v any) {
	data, err := json.MarshalIndent(v, "", "    ")
	if err != nil {
		panic(err)
	}
	fmt.Printf("JSON:\n%s\n", string(data))
}

// PrintError formats error message.
func PrintError(err error) {
	var msg strings.Builder
	for line := range strings.SplitSeq(err.Error(), "; ") {
		msg.WriteString("- " + line + "\n")
	}
	fmt.Printf("ERROR:\n\n%s\n", msg.String())
}

Output:
ERROR:

- must be less or equal to 44

JSON:
{
    "code": "ECInvRange",
    "error": "must be less or equal to 44"
}

package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/ctx42/verax/pkg/verax"
)

type Planet struct {
	Position int    `json:"position"`
	Name     string `json:"name" solar:"planet_name"`
	Life     float64
}

func (p *Planet) Validate() error {
	return verax.ValidateStruct(
		p,
		verax.Field(&p.Position, verax.Min(1), verax.Max(8)),
		verax.Field(&p.Name, verax.Length(4, 7)).Tag("solar"),
		verax.Field(&p.Life, verax.Min(0.0), verax.Max(1.0)),
	)
}

func main() {
	planets := []*Planet{
		{1, "Mer", 0},
		{3, "Earth", 1.0},
		{9, "X", 0.1},
	}

	err := verax.Validate(planets)

	PrintError(err)
	PrintJSON(err)
}

// PrintJSON marshals value to JSON string.
func PrintJSON(v any) {
	data, err := json.MarshalIndent(v, "", "    ")
	if err != nil {
		panic(err)
	}
	fmt.Printf("JSON:\n%s\n", string(data))
}

// PrintError formats error message.
func PrintError(err error) {
	var msg strings.Builder
	for line := range strings.SplitSeq(err.Error(), "; ") {
		msg.WriteString("- " + line + "\n")
	}
	fmt.Printf("ERROR:\n\n%s\n", msg.String())
}

Output:
ERROR:

- 0.planet_name: the length must be between 4 and 7
- 2.planet_name: the length must be between 4 and 7
- 2.position: must be less or equal to 8

JSON:
{
    "0.planet_name": {
        "code": "ECInvLength",
        "error": "the length must be between 4 and 7"
    },
    "2.planet_name": {
        "code": "ECInvLength",
        "error": "the length must be between 4 and 7"
    },
    "2.position": {
        "code": "ECInvRange",
        "error": "must be less or equal to 8"
    }
}

package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/ctx42/verax/pkg/verax"
)

type Planet struct {
	Position int    `json:"position"`
	Name     string `json:"name" solar:"planet_name"`
	Life     float64
}

func (p *Planet) Validate() error {
	return verax.ValidateStruct(
		p,
		verax.Field(&p.Position, verax.Min(1), verax.Max(8)),
		verax.Field(&p.Name, verax.Length(4, 7)).Tag("solar"),
		verax.Field(&p.Life, verax.Min(0.0), verax.Max(1.0)),
	)
}

func main() {
	planet := Planet{9, "PlanetXYZ", -1}

	err := verax.ValidateStruct(
		&planet,
		verax.Field(&planet.Position, verax.Min(1), verax.Max(8)),
		verax.Field(&planet.Name, verax.Length(4, 7)),
		verax.Field(&planet.Life, verax.Min(0.0), verax.Max(1.0)),
	)

	PrintError(err)
	PrintJSON(err)
}

// PrintJSON marshals value to JSON string.
func PrintJSON(v any) {
	data, err := json.MarshalIndent(v, "", "    ")
	if err != nil {
		panic(err)
	}
	fmt.Printf("JSON:\n%s\n", string(data))
}

// PrintError formats error message.
func PrintError(err error) {
	var msg strings.Builder
	for line := range strings.SplitSeq(err.Error(), "; ") {
		msg.WriteString("- " + line + "\n")
	}
	fmt.Printf("ERROR:\n\n%s\n", msg.String())
}

Output:
ERROR:

- Life: must be greater or equal to 0
- name: the length must be between 4 and 7
- position: must be less or equal to 8

JSON:
{
    "Life": {
        "code": "ECInvRange",
        "error": "must be greater or equal to 0"
    },
    "name": {
        "code": "ECInvLength",
        "error": "the length must be between 4 and 7"
    },
    "position": {
        "code": "ECInvRange",
        "error": "must be less or equal to 8"
    }
}

package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/ctx42/verax/pkg/verax"
)

type Planet struct {
	Position int    `json:"position"`
	Name     string `json:"name" solar:"planet_name"`
	Life     float64
}

func (p *Planet) Validate() error {
	return verax.ValidateStruct(
		p,
		verax.Field(&p.Position, verax.Min(1), verax.Max(8)),
		verax.Field(&p.Name, verax.Length(4, 7)).Tag("solar"),
		verax.Field(&p.Life, verax.Min(0.0), verax.Max(1.0)),
	)
}

func main() {
	planet := Planet{1, "Mer", 0.0}

	err := verax.ValidateStruct(
		&planet,
		verax.Field(&planet.Name, verax.Length(4, 7)).Tag("solar"),
	)

	PrintError(err)
	PrintJSON(err)
}

// PrintJSON marshals value to JSON string.
func PrintJSON(v any) {
	data, err := json.MarshalIndent(v, "", "    ")
	if err != nil {
		panic(err)
	}
	fmt.Printf("JSON:\n%s\n", string(data))
}

// PrintError formats error message.
func PrintError(err error) {
	var msg strings.Builder
	for line := range strings.SplitSeq(err.Error(), "; ") {
		msg.WriteString("- " + line + "\n")
	}
	fmt.Printf("ERROR:\n\n%s\n", msg.String())
}

Output:
ERROR:

- planet_name: the length must be between 4 and 7

JSON:
{
    "planet_name": {
        "code": "ECInvLength",
        "error": "the length must be between 4 and 7"
    }
}