Mishras

A powerful factory library for Elixir that simplifies test data creation for Ecto schemas with support for associations, embeds, and custom data generation.

Overview

Mishras provides a protocol-based factory system that automatically handles:

• Associations (belongs_to, has_one, has_many, many_to_many)
• Embedded schemas (embeds_one, embeds_many)
• Primary key generation (both integer and binary_id)
• Custom data generation through implementation modules

Installation

Add mishras to your list of dependencies in mix.exs:

def deps do
  [
    {:mishras, "~> 0.1.0"}
  ]
end

Configuration

Configure your repo in config/config.exs:

config :mishras, repo: MyApp.Repo

Usage

Basic Schema Factory

defmodule MyApp.User do
  use Ecto.Schema
  
  schema "users" do
    field :name, :string
    field :email, :string
  end
  
  def changeset(struct \\ %__MODULE__{}, attrs) do
    struct
    |> Ecto.Changeset.cast(attrs, [:name, :email])
    |> Ecto.Changeset.validate_required([:name, :email])
  end
end

# Implement the factory
defimpl Mishras.Factory, for: MyApp.User do
  use Mishras
  
  def build_map(_mode, _attrs) do
    %{
      name: "John Doe",
      email: "john@example.com"
    }
  end
end

Creating Test Data

alias Mishras.Factory
# Build a struct (no database insertion)
user = Factory.build(MyApp.User, %{name: "Jane"})

# Insert into database
user = Factory.insert(MyApp.User, %{email: "jane@example.com"})

Advanced Features

• Automatic association handling: Referenced schemas are automatically built/inserted
• Embedded schema support: Nested embeds are properly constructed
• Custom ID generation: Override autogenerate_id/1 for custom primary key logic
• Mode-aware factories: Different behavior for :build vs :insert modes

API

Main Functions

• Mishras.Factory.build/2 - Build a struct without database insertion
• Mishras.Factory.insert/2 - Insert a record into the database

Implementation Callbacks

• build_map/2 - Required. Defines default attributes for the schema
• autogenerate_id/1 - Optional. Custom primary key generation logic

License

This project is licensed under the MIT License.