gofiber-validator-middleware

gofiber-validator-middleware is a gofiber middleware to generate a go-playground/validator singleton for use in validating DTOs in handlers (or whatever you need to validate).

Installation

go get github.com/rgglez/gofiber-validator-middleware

Configuration

• Next defines a function to skip this middleware when returned true.
• Validator injected instance, if nil a new validator will be created.
• ContextKey is the key used to store the validator in context. Optional. Default: "validator"
• CustomValidations allows you to register custom validation functions. Optional. Default: nil

Basic usage

import (
    gofibervalidator "github.com/rgglez/gofiber-validator-middleware/gofibervalidator"
)

// Custom validation function example
func isEvenNumber(fl validator.FieldLevel) bool {
	value := fl.Field().Int()
	return value%2 == 0
}

app.Use(gofibervalidator.New(gofibervalidator.Config{
    ContextKey: "validator",
    CustomValidations: map[string]validator.Func{
        "even": isEvenNumber,
    },
    Next: func(c *fiber.Ctx) bool {
        // Skip validation for specific routes
        return c.Path() == "/health"
    },
}))

Example

An example is included in the example directory. To execute it:

1. Enter the example directory.
2. Run the example:

   go run .

3. You can try 3 use cases:

• Skip validation (GET): http://127.0.0.1:3000/health
• Validate user "creation" (POST): http://127.0.0.1:3000/users
• Validate product "creation" (POST): http://127.0.0.1:3000/products

You can use resting or the plugin of your choice, or tools like curl, to try the endpoints.

Dependencies

• github.com/gofiber/fiber/v2
• go-playground/validator

Tests

Run the tests with:

go test ./gofibervalidator/... -v

Test cases

Test	What it verifies
TestNew_DefaultConfig	Middleware stores a *validator.Validate under the "validator" key by default
TestNew_CustomContextKey	Custom ContextKey is used; default key is absent
TestNew_EmptyContextKeyFallsBackToDefault	Empty ContextKey falls back to "validator"
TestNew_NextSkipsMiddleware	When Next returns true, middleware is skipped and no validator is stored
TestNew_CustomValidatorInstance	A pre-built *validator.Validate provided via config is used as-is
TestNew_CustomValidations	Custom tag functions registered via CustomValidations work correctly
TestGetValidator_DefaultKey	GetValidator retrieves the instance using the default key
TestGetValidator_CustomKey	GetValidator retrieves via a custom key; wrong key returns nil
TestGetValidator_NotInContext	GetValidator returns nil when no middleware is registered
TestGetValidator_ValidatesStruct	The retrieved validator correctly validates struct fields

License

Copyright (c) 2026 Rodolfo González González.

Licensed under the Apache 2.0 license. Read the LICENSE file.