raindrops

elixir/raindrops/.exercism/config.json

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+{
+  "authors": [
+    "rubysolo"
+  ],
+  "contributors": [
+    "andrewsardone",
+    "angelikatyborska",
+    "Cohen-Carlisle",
+    "dalexj",
+    "devonestes",
+    "jinyeow",
+    "lpil",
+    "neenjaw",
+    "parkerl",
+    "sotojuan",
+    "Teapane",
+    "waiting-for-dev"
+  ],
+  "files": {
+    "solution": [
+      "lib/raindrops.ex"
+    ],
+    "test": [
+      "test/raindrops_test.exs"
+    ],
+    "example": [
+      ".meta/example.ex"
+    ]
+  },
+  "blurb": "Convert a number into its corresponding raindrop sounds - Pling, Plang and Plong.",
+  "source": "A variation on FizzBuzz, a famous technical interview question that is intended to weed out potential candidates. That question is itself derived from Fizz Buzz, a popular children's game for teaching division.",
+  "source_url": "https://en.wikipedia.org/wiki/Fizz_buzz"
+}

elixir/raindrops/.exercism/metadata.json

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+{"track":"elixir","exercise":"raindrops","id":"e9ff118098084dc9befe7fe0a2e71ed1","url":"https://exercism.org/tracks/elixir/exercises/raindrops","handle":"negrienko","is_requester":true,"auto_approve":false}

elixir/raindrops/.formatter.exs

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

elixir/raindrops/.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").
+raindrops-*.tar
+

elixir/raindrops/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/raindrops.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/raindrops/README.md

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+# Raindrops
+
+Welcome to Raindrops on Exercism's Elixir Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Introduction
+
+Raindrops is a slightly more complex version of the FizzBuzz challenge, a classic interview question.
+
+## Instructions
+
+Your task is to convert a number into its corresponding raindrop sounds.
+
+If a given number:
+
+- is divisible by 3, add "Pling" to the result.
+- is divisible by 5, add "Plang" to the result.
+- is divisible by 7, add "Plong" to the result.
+- **is not** divisible by 3, 5, or 7, the result should be the number as a string.
+
+## Examples
+
+- 28 is divisible by 7, but not 3 or 5, so the result would be `"Plong"`.
+- 30 is divisible by 3 and 5, but not 7, so the result would be `"PlingPlang"`.
+- 34 is not divisible by 3, 5, or 7, so the result would be `"34"`.
+
+~~~~exercism/note
+A common way to test if one number is evenly divisible by another is to compare the [remainder][remainder] or [modulus][modulo] to zero.
+Most languages provide operators or functions for one (or both) of these.
+
+[remainder]: https://exercism.org/docs/programming/operators/remainder
+[modulo]: https://en.wikipedia.org/wiki/Modulo_operation
+~~~~
+
+## Source
+
+### Created by
+
+- @rubysolo
+
+### Contributed to by
+
+- @andrewsardone
+- @angelikatyborska
+- @Cohen-Carlisle
+- @dalexj
+- @devonestes
+- @jinyeow
+- @lpil
+- @neenjaw
+- @parkerl
+- @sotojuan
+- @Teapane
+- @waiting-for-dev
+
+### Based on
+
+A variation on FizzBuzz, a famous technical interview question that is intended to weed out potential candidates. That question is itself derived from Fizz Buzz, a popular children's game for teaching division. - https://en.wikipedia.org/wiki/Fizz_buzz

elixir/raindrops/lib/raindrops.ex

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+defmodule Raindrops do
+  @doc """
+  Returns a string based on raindrop factors.
+
+  - If the number contains 3 as a prime factor, output 'Pling'.
+  - If the number contains 5 as a prime factor, output 'Plang'.
+  - If the number contains 7 as a prime factor, output 'Plong'.
+  - If the number does not contain 3, 5, or 7 as a prime factor,
+    just pass the number's digits straight through.
+  """
+  @results [
+    {3, "Pling"},
+    {5, "Plang"},
+    {7, "Plong"}
+  ]
+
+  @spec convert(pos_integer) :: String.t()
+  def convert(number) do
+    @results
+    |> Enum.map_join(&mapper(number, &1))
+    |> case do
+      "" -> Integer.to_string(number)
+      result -> result
+    end
+  end
+
+  defp mapper(number, {factor, value}) do
+    if rem(number, factor) == 0, do: value, else: ""
+  end
+end

elixir/raindrops/mix.exs

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+defmodule Raindrops.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :raindrops,
+      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/raindrops/test/raindrops_test.exs

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+defmodule RaindropsTest do
+  use ExUnit.Case
+
+  test "1" do
+    assert Raindrops.convert(1) == "1"
+  end
+
+  test "3" do
+    assert Raindrops.convert(3) == "Pling"
+  end
+
+  test "5" do
+    assert Raindrops.convert(5) == "Plang"
+  end
+
+  test "7" do
+    assert Raindrops.convert(7) == "Plong"
+  end
+
+  test "6" do
+    assert Raindrops.convert(6) == "Pling"
+  end
+
+  test "8" do
+    assert Raindrops.convert(8) == "8"
+  end
+
+  test "9" do
+    assert Raindrops.convert(9) == "Pling"
+  end
+
+  test "10" do
+    assert Raindrops.convert(10) == "Plang"
+  end
+
+  test "14" do
+    assert Raindrops.convert(14) == "Plong"
+  end
+
+  test "15" do
+    assert Raindrops.convert(15) == "PlingPlang"
+  end
+
+  test "21" do
+    assert Raindrops.convert(21) == "PlingPlong"
+  end
+
+  test "25" do
+    assert Raindrops.convert(25) == "Plang"
+  end
+
+  test "35" do
+    assert Raindrops.convert(35) == "PlangPlong"
+  end
+
+  test "49" do
+    assert Raindrops.convert(49) == "Plong"
+  end
+
+  test "52" do
+    assert Raindrops.convert(52) == "52"
+  end
+
+  test "105" do
+    assert Raindrops.convert(105) == "PlingPlangPlong"
+  end
+
+  test "12121" do
+    assert Raindrops.convert(12121) == "12121"
+  end
+end

elixir/raindrops/test/test_helper.exs

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