ExSamples

Initializes lists of maps, structs or keyword lists using tabular data in Elixir.

ExSamples helps you to describe data of the same type in a more compact and readable way. Specially useful when defining sample data (e.g. for tests). Here is an example:

countries =
  samples do
    :id | :name           | :currency                    | :language    | :population
     1  | "Brazil"        | "Real (BRL)"                 | "Portuguese" | 204_451_000
     2  | "United States" | "United States Dollar (USD)" | "English"    | 321_605_012
     3  | "Austria"       | "Euro (EUR)"                 | "German"     |   8_623_073
     4  | "Sweden"        | "Swedish krona (SEK)"        | "Swedish"    |   9_801_616
  end

iex> IO.inspect(countries)
[
  %{
    currency: "Real (BRL)",
    id: 1,
    language: "Portuguese",
    name: "Brazil",
    population: 204451000
  },
  %{
    currency: "United States Dollar (USD)",
    id: 2,
    language: "English",
    name: "United States",
    population: 321605012
  },
  %{
    currency: "Euro (EUR)",
    id: 3,
    language: "German",
    name: "Austria",
    population: 8623073
  },
  %{
    currency: "Swedish krona (SEK)",
    id: 4,
    language: "Swedish",
    name: "Sweden",
    population: 9801616
  }
]

You can see it in action with livebook with guides/usage.livemd.

Installation

Add :exsamples as a dependency in your mix.exs file.

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

Configure the formatter (only for Elixir >= v1.13.2)

Add Samples.FormatterPlugin to the list of plugins in your .formatter.exs:

[
  plugins: [Samples.FormatterPlugin],
  ...
]

If you don't configure the formatter, mix format will remove all extra spaces you add to make your tables look nice.

Usage

import ExSamples

samples do
  :name       | :country        | :city           | :admin
  "Christian" | "United States" | "New York City" | false
  "Peter"     | "Germany"       | "Berlin"        | true
  "José"      | "Brazil"        | "São Paulo"     | false
  "Ingrid"    | "Austria"       | "Salzburg"      | false
  "Lucas"     | "Brazil"        | "Fortaleza"     | true
end

By default samples initializes a list of maps. But you can also define structs and keyword lists.

Initializing structs

import ExSamples

defmodule Country do
  defstruct [:id, :name, :currency, :language, :population]
end

samples as: Country do
  :id | :name           | :currency                    | :language    | :population
   1  | "Brazil"        | "Real (BRL)"                 | "Portuguese" | 204_451_000
   2  | "United States" | "United States Dollar (USD)" | "English"    | 321_605_012
end

Initializing keyword lists

samples as: [] do
  :id | :name           | :currency             | :language    | :population
   3  | "Austria"       | "Euro (EUR)"          | "German"     |   8_623_073
   4  | "Sweden"        | "Swedish krona (SEK)" | "Swedish"    |   9_801_616
end

Assigning variables as structs

defmodule Country do
  defstruct [:name, :currency, :language]
end

defmodule User do
  defstruct [:id, :name, :country, :admin, :last_login]
end

samples do
  Country  | :name           | :currency                    | :language
  country1 | "Brazil"        | "Real (BRL)"                 | "Portuguese"
  country2 | "United States" | "United States Dollar (USD)" | "English"
  country3 | "Austria"       | "Euro (EUR)"                 | "German"
end

samples do
  User  | :id | :name       | :country | :admin | :last_login
  user1 |  16 | "Lucas"     | country1 | false  | {2015, 10, 08}
  user2 | 327 | "Ingrid"    | country3 | true   | {2014, 09, 12}
  user3 |  34 | "Christian" | country2 | false  | {2015, 01, 24}
end

iex> IO.puts "Name: #{user1.name}, Country: #{user1.country.name}"
Name: Lucas, Country: Brazil

Assigning variables as maps

samples do
   %{}  | :name       | :country        | :city
  user1 | "Christian" | "United States" | "New York City"
  user2 | "Ingrid"    | "Austria"       | "Salzburg"
end

Assigning variables as keyword lists

samples do
    []  | :name       | :country        | :city
  user1 | "Christian" | "United States" | "New York City"
  user2 | "Ingrid"    | "Austria"       | "Salzburg"
end

License

(The MIT License)

Copyright (c) 2022 Marlus Saraiva

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.