rails_react_errors

Consistent error responses for Rails APIs used by React frontends.

rails_react_errors standardizes API error responses so React applications can easily handle validation errors, authentication errors, and server failures.

Instead of handling multiple Rails error formats, this gem provides a single predictable JSON structure.

---

Installation

Add this line to your application's Gemfile:

gem "rails_react_errors"

Then run:

bundle install

---

Quick Setup

Include the controller module in your base controller.

class ApplicationController < ActionController::API
  include RailsReactErrors::Controller
end

That's it. Your Rails API will now automatically return standardized error responses.

---

Automatic Exception Handling

The gem automatically handles common Rails exceptions and converts them into consistent JSON responses.

Supported exceptions:

• ActiveRecord::RecordNotFound
• ActiveRecord::RecordInvalid
• ActiveRecord::RecordNotUnique
• ActionController::ParameterMissing
• JSON::ParserError
• StandardError (optional)

Example:

class UsersController < ApplicationController
  def show
    user = User.find(params[:id])
    render json: user
  end
end

If the record does not exist:

{
  "success": false,
  "message": "Couldn't find User with 'id'=99",
  "code": "NOT_FOUND",
  "errors": {}
}

---

Validation Error Example

class UsersController < ApplicationController
  def create
    user = User.create!(user_params)
    render json: { success: true, data: user }, status: :created
  end

  private

  def user_params
    params.require(:user).permit(:email, :password)
  end
end

Response:

{
  "success": false,
  "message": "Validation failed",
  "code": "VALIDATION_ERROR",
  "errors": {
    "email": ["Email can't be blank"]
  }
}

---

JSON Parsing Error

If an invalid JSON payload is sent:

{ email: "test"

Response:

{
  "success": false,
  "message": "Invalid JSON payload",
  "code": "INVALID_JSON",
  "errors": {}
}

---

Available Helper Methods

You can also manually render errors if needed.

render_validation_error(record)
render_not_found_error("User not found")
render_parameter_missing_error("param is missing")
render_conflict_error("Duplicate record")
render_server_error("Something went wrong")
render_error(message:, code:, status:, errors: {})

---

Custom Exception Mapping

You can configure your own exceptions.

RailsReactErrors.configure do |config|
  config.custom_exceptions = {
    "Pundit::NotAuthorizedError" => {
      code: "FORBIDDEN",
      status: :forbidden
    },
    "JWT::DecodeError" => {
      code: "INVALID_TOKEN",
      status: :unauthorized
    }
  }
end

---

Enable Global Error Handling

To automatically handle unexpected errors:

RailsReactErrors.configure do |config|
  config.rescue_standard_error = true
end

---

License

MIT License

---

Author

Manish Prajapati