two_fer

elixir/two-fer/.exercism/config.json

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+{
+  "authors": [
+    "Bscruz19"
+  ],
+  "contributors": [
+    "angelikatyborska",
+    "Cohen-Carlisle",
+    "devonestes",
+    "neenjaw"
+  ],
+  "files": {
+    "solution": [
+      "lib/two_fer.ex"
+    ],
+    "test": [
+      "test/two_fer_test.exs"
+    ],
+    "example": [
+      ".meta/example.ex"
+    ]
+  },
+  "blurb": "Create a sentence of the form \"One for X, one for me.\".",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/757"
+}

elixir/two-fer/.exercism/metadata.json

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+{"track":"elixir","exercise":"two-fer","id":"b3c872e5a42f4fd29e819eb5d0fd6ea9","url":"https://exercism.org/tracks/elixir/exercises/two-fer","handle":"negrienko","is_requester":true,"auto_approve":false}

elixir/two-fer/.formatter.exs

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+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

elixir/two-fer/.gitignore

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+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+two_fer-*.tar
+

elixir/two-fer/HELP.md

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+# Help
+
+## Running the tests
+
+From the terminal, change to the base directory of the exercise then execute the tests with:
+
+```bash
+$ mix test
+```
+
+This will execute the test file found in the `test` subfolder -- a file ending in `_test.exs`
+
+Documentation:
+
+* [`mix test` - Elixir's test execution tool](https://hexdocs.pm/mix/Mix.Tasks.Test.html)
+* [`ExUnit` - Elixir's unit test library](https://hexdocs.pm/ex_unit/ExUnit.html)
+
+## Pending tests
+
+In test suites of practice exercises, all but the first test have been tagged to be skipped.
+
+Once you get a test passing, you can unskip the next one by commenting out the relevant `@tag :pending` with a `#` symbol.
+
+For example:
+
+```elixir
+# @tag :pending
+test "shouting" do
+  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
+end
+```
+
+If you wish to run all tests at once, you can include all skipped test by using the `--include` flag on the `mix test` command:
+
+```bash
+$ mix test --include pending
+```
+
+Or, you can enable all the tests by commenting out the `ExUnit.configure` line in the file `test/test_helper.exs`.
+
+```elixir
+# ExUnit.configure(exclude: :pending, trace: true)
+```
+
+## Useful `mix test` options
+
+* `test/<FILE>.exs:LINENUM` - runs only a single test, the test from `<FILE>.exs` whose definition is on line `LINENUM`
+* `--failed` - runs only tests that failed the last time they ran
+* `--max-failures` - the suite stops evaluating tests when this number of test failures
+is reached
+* `--seed 0` - disables randomization so the tests in a single file will always be ran
+in the same order they were defined in
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit lib/two_fer.ex` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Elixir track's documentation](https://exercism.org/docs/tracks/elixir)
+- The [Elixir track's programming category on the forum](https://forum.exercism.org/c/programming/elixir)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+If you're stuck on something, it may help to look at some of the [available resources](https://exercism.org/docs/tracks/elixir/resources) out there where answers might be found.

elixir/two-fer/README.md

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+# Two Fer
+
+Welcome to Two Fer on Exercism's Elixir Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Introduction
+
+In some English accents, when you say "two for" quickly, it sounds like "two fer".
+Two-for-one is a way of saying that if you buy one, you also get one for free.
+So the phrase "two-fer" often implies a two-for-one offer.
+
+Imagine a bakery that has a holiday offer where you can buy two cookies for the price of one ("two-fer one!").
+You go for the offer and (very generously) decide to give the extra cookie to a friend.
+
+## Instructions
+
+Your task is to determine what you will say as you give away the extra cookie.
+
+If your friend likes cookies, and is named Do-yun, then you will say:
+
+```text
+One for Do-yun, one for me.
+```
+
+If your friend doesn't like cookies, you give the cookie to the next person in line at the bakery.
+Since you don't know their name, you will say _you_ instead.
+
+```text
+One for you, one for me.
+```
+
+Here are some examples:
+
+| Name   | Dialogue                    |
+| :----- | :-------------------------- |
+| Alice  | One for Alice, one for me.  |
+| Bohdan | One for Bohdan, one for me. |
+|        | One for you, one for me.    |
+| Zaphod | One for Zaphod, one for me. |
+
+## Source
+
+### Created by
+
+- @Bscruz19
+
+### Contributed to by
+
+- @angelikatyborska
+- @Cohen-Carlisle
+- @devonestes
+- @neenjaw
+
+### Based on
+
+https://github.com/exercism/problem-specifications/issues/757

elixir/two-fer/lib/two_fer.ex

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+defmodule TwoFer do
+  @doc """
+  Two-fer or 2-fer is short for two for one. One for you and one for me.
+  """
+  @spec two_fer(String.t()) :: String.t()
+  def two_fer(name \\ "you") when is_binary(name) do
+    "One for #{name}, one for me."
+  end
+end

elixir/two-fer/mix.exs

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+defmodule TwoFer.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :two_fer,
+      version: "0.1.0",
+      # elixir: "~> 1.8",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      # {:dep_from_hexpm, "~> 0.3.0"},
+      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+    ]
+  end
+end

elixir/two-fer/test/test_helper.exs

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+ExUnit.start()
+ExUnit.configure(exclude: :pending, trace: true)

elixir/two-fer/test/two_fer_test.exs

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+defmodule TwoFerTest do
+  use ExUnit.Case
+
+  test "no name given" do
+    assert TwoFer.two_fer() == "One for you, one for me."
+  end
+
+  # @tag :pending
+  test "a name given" do
+    assert TwoFer.two_fer("Alice") == "One for Alice, one for me."
+  end
+
+  # @tag :pending
+  test "another name given" do
+    assert TwoFer.two_fer("Bob") == "One for Bob, one for me."
+  end
+
+  # @tag :pending
+  test "when the argument is a number" do
+    assert_raise FunctionClauseError, fn ->
+      TwoFer.two_fer(10)
+    end
+  end
+
+  # @tag :pending
+  test "when the argument is an atom" do
+    assert_raise FunctionClauseError, fn ->
+      TwoFer.two_fer(:bob)
+    end
+  end
+
+  # @tag :pending
+  test "when the argument is a charlist" do
+    assert_raise FunctionClauseError, fn ->
+      refute TwoFer.two_fer(~c"Jon Snow")
+    end
+  end
+end