# Myrmidex
A light wrapper around `StreamData`. Generate any data on the fly, or model
the underlying types and common fields of domain-specific structs or schemas,
optionally using custom generators. Aimed at speeding up test setup, and
maximizing reusability of factory data throughout testing and development.
## Installation
Add to your list of test dependencies in `mix.exs`, optionally also including
in dev if you want to be able to use:
```elixir
def deps do
[
{:myrmidex, "~> 0.2.0", only: [:test, :dev]}
]
end
```
## Usage
Produce a stream of generically representative data from any term:
```elixir
iex> "🐜"
...> |> Myrmidex.many()
...> |> Enum.join(" ")
"🐩 🐰 🐡 🐂 🐏 🐁 🐋 🐤 🐪 🐭 🐏 🐨 🐋 🐁 🐚 🐤"
iex> %{species: "🐜"}
...> |> Myrmidex.affix(kingdom: "Animalia", class: "Insecta")
...> |> Myrmidex.many()
[
%{
kingdom: "Animalia",
class: "Insecta",
species: "🪰"
},
%{
kingdom: "Animalia",
class: "Insecta",
species: "🐞"
},
...
]
```
See the [main module](`Myrmidex`) (`h Myrmidex`) for examples of mocking
structs and schemas, defining custom generator schemas, or hooking
generation to persistance via factories.
## Design goals
- Initial, usable defaults, which can be extended with domain-specific
concerns
- Decouple any requirements wrt to seeding a datasource from the generation
of data
- Avoid unnecessary dependencies and testing setup
- Avoid any kind of dsl (besides that introduced by StreamData in
`ExUnitProperties`, which is useful for property-based testing)
- Rely on reflection and introspection as much as possible to avoid boilerplate
and repetition, and also to keep factories in sync with schemas
- Establish a robust, composable api from which to generate mock data
in many situations: test setup, dev setup, prototyping, etc., testing
changesets and validation vs testing context functions, and so on.
- Reduce the complexity (and conversely, increase the flexibilty &
reusability) involved in mocking schemas with associations, or other
interdependencies between fields
- Retain compatibilty with StreamData and property testing
## Roadmap
- ~~Better generation of vanilla maps and lists~~
- Reporting on generated terms
- Better defaults for strings/emails etc.
- Option to control shrinking
- Option to control the default count
- Inference/generation of ISO dates and datetimes
- Better integration with vanilla streams
