From af3b5c40f889eafb5c7be4e081aaef5fcaee6ddd Mon Sep 17 00:00:00 2001 From: Danylo Negrienko Date: Tue, 5 Mar 2024 17:11:42 -0500 Subject: [PATCH] community_garden --- elixir/community-garden/.exercism/config.json | 25 ++++ .../community-garden/.exercism/metadata.json | 1 + elixir/community-garden/.formatter.exs | 4 + elixir/community-garden/.gitignore | 24 ++++ elixir/community-garden/HELP.md | 75 ++++++++++ elixir/community-garden/HINTS.md | 36 +++++ elixir/community-garden/README.md | 97 +++++++++++++ .../community-garden/lib/community_garden.ex | 38 +++++ elixir/community-garden/mix.exs | 28 ++++ .../test/community_garden_test.exs | 131 ++++++++++++++++++ elixir/community-garden/test/test_helper.exs | 2 + 11 files changed, 461 insertions(+) create mode 100644 elixir/community-garden/.exercism/config.json create mode 100644 elixir/community-garden/.exercism/metadata.json create mode 100644 elixir/community-garden/.formatter.exs create mode 100644 elixir/community-garden/.gitignore create mode 100644 elixir/community-garden/HELP.md create mode 100644 elixir/community-garden/HINTS.md create mode 100644 elixir/community-garden/README.md create mode 100644 elixir/community-garden/lib/community_garden.ex create mode 100644 elixir/community-garden/mix.exs create mode 100644 elixir/community-garden/test/community_garden_test.exs create mode 100644 elixir/community-garden/test/test_helper.exs diff --git a/elixir/community-garden/.exercism/config.json b/elixir/community-garden/.exercism/config.json new file mode 100644 index 0000000..e8bbe5e --- /dev/null +++ b/elixir/community-garden/.exercism/config.json @@ -0,0 +1,25 @@ +{ + "authors": [ + "neenjaw" + ], + "contributors": [ + "angelikatyborska", + "jrr", + "efx", + "justin-m-morgan", + "cr0t" + ], + "files": { + "solution": [ + "lib/community_garden.ex" + ], + "test": [ + "test/community_garden_test.exs" + ], + "exemplar": [ + ".meta/exemplar.ex" + ] + }, + "language_versions": ">=1.10", + "blurb": "Learn about the Agent module by helping your local community handle community garden registrations." +} diff --git a/elixir/community-garden/.exercism/metadata.json b/elixir/community-garden/.exercism/metadata.json new file mode 100644 index 0000000..e70f054 --- /dev/null +++ b/elixir/community-garden/.exercism/metadata.json @@ -0,0 +1 @@ +{"track":"elixir","exercise":"community-garden","id":"5138f62059e2481ca67da71571d11fb7","url":"https://exercism.org/tracks/elixir/exercises/community-garden","handle":"negrienko","is_requester":true,"auto_approve":false} \ No newline at end of file diff --git a/elixir/community-garden/.formatter.exs b/elixir/community-garden/.formatter.exs new file mode 100644 index 0000000..d2cda26 --- /dev/null +++ b/elixir/community-garden/.formatter.exs @@ -0,0 +1,4 @@ +# Used by "mix format" +[ + inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"] +] diff --git a/elixir/community-garden/.gitignore b/elixir/community-garden/.gitignore new file mode 100644 index 0000000..464f0c3 --- /dev/null +++ b/elixir/community-garden/.gitignore @@ -0,0 +1,24 @@ +# 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"). +agents-*.tar + diff --git a/elixir/community-garden/HELP.md b/elixir/community-garden/HELP.md new file mode 100644 index 0000000..2926baa --- /dev/null +++ b/elixir/community-garden/HELP.md @@ -0,0 +1,75 @@ +# 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/.exs:LINENUM` - runs only a single test, the test from `.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/community_garden.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. \ No newline at end of file diff --git a/elixir/community-garden/HINTS.md b/elixir/community-garden/HINTS.md new file mode 100644 index 0000000..eaa7941 --- /dev/null +++ b/elixir/community-garden/HINTS.md @@ -0,0 +1,36 @@ +# Hints + +## General + +- Read about the [`Agent` module][getting-started-agent] in the Getting Started guide. +- Read the documentation about the [`Agent` module][elixir-doc-agent]. +- Watch [ElixirCasts: Introduction to Agents][elixircasts-agent]. + +## 1. Open the garden + +- Review the [`Agent`][elixir-doc-agent] documentation. +- The function to initialize the state of the _agent process_ must return the initial state. + +## 2. List the registrations + +- The [`Agent`][elixir-doc-agent] module contains many functions to obtain the current state of the _agent process_. + +## 3. Register plots to a person + +- The [`Agent`][elixir-doc-agent] module contains functions to obtain and update the state of the _agent process_. +- The functions generally require a function which transforms the state and returns a specific form. +- In order to keep track of the id for the next plot to assign, your _agent process_'s state needs to keep track of the plots and also the next id to use for a plot. + +## 4. Release plots + +- The [`Agent`][elixir-doc-agent] module contains functions to obtain and update the state of the _agent process_. +- The functions generally require a function which transforms the state and returns the next state. + +## 5. Get a registered plot + +- The [`Agent`][elixir-doc-agent] module contains functions to obtain the state of the _agent process_. +- Obtain the plot from, then handle the result to return the correct result. + +[elixircasts-agent]: https://elixircasts.io/intro-to-agents +[elixir-doc-agent]: https://hexdocs.pm/elixir/Agent.html +[getting-started-agent]: https://hexdocs.pm/elixir/agents.html \ No newline at end of file diff --git a/elixir/community-garden/README.md b/elixir/community-garden/README.md new file mode 100644 index 0000000..5eed505 --- /dev/null +++ b/elixir/community-garden/README.md @@ -0,0 +1,97 @@ +# Community Garden + +Welcome to Community Garden on Exercism's Elixir Track. +If you need help running the tests or submitting your code, check out `HELP.md`. +If you get stuck on the exercise, check out `HINTS.md`, but try and solve it without using those first :) + +## Introduction + +## Agent + +The `Agent` module facilitates an abstraction for spawning [processes and the _receive-send_ loop][exercism-processes]. From here, we will call processes started using the `Agent` module _'agent processes'_. An _agent process_ might be chosen to represent a central shared state. + +To start an _agent process_, `Agent` provides the `start/2` function. The supplied function when `start`_-ing_ the _agent process_ returns the initial state of the process: + +```elixir +# Start an agent process with an initial value of an empty list +{:ok, agent_pid} = Agent.start(fn -> [] end) +``` + +Just like `Map` or `List`, `Agent` provides many functions for working with _agent processes_. + +It is customary to organize and encapsulate all `Agent`-related functionality into a module for the domain being modeled. + +[exercism-processes]: https://exercism.org/tracks/elixir/concepts/processes + +## Instructions + +Your community association has asked you to implement a simple registry application to manage the community garden registrations. The `Plot` struct has already been provided for you. + +## 1. Open the garden + +Implement the `CommunityGarden.start/1` function, it should receive an optional keyword list of options to pass forward to the _agent process_. The garden's initial state should be initialized to represent an empty collection of plots. It should return an `:ok` tuple with the garden's pid. + +```elixir +{:ok, pid} = CommunityGarden.start() +# => {:ok, #PID<0.112.0>} +``` + +## 2. List the registrations + +Implement the `CommunityGarden.list_registrations/1` function. It should receive the `pid` for the community garden. It should return a list of the stored plots that are registered. + +```elixir +CommunityGarden.list_registrations(pid) +# => [] +``` + +> At this point, we haven't added the ability to register a plot, so this list should be empty + +## 3. Register plots to a person + +Implement the `CommunityGarden.register/2` function. It should receive the `pid` for the community garden and a name to register the plot. It should return the `Plot` struct with the plot's id and person registered to when it is successful. + +The ids should be incremental and unique. You can keep an id counter in the agent's state. + +```elixir +CommunityGarden.register(pid, "Emma Balan") +# => %Plot{plot_id: 1, registered_to: "Emma Balan"} +CommunityGarden.list_registrations(pid) +# => [%Plot{plot_id: 1, registered_to: "Emma Balan"}] +``` + +## 4. Release plots + +Implement the `CommunityGarden.release/2` function. It should receive the `pid` and `id` of the plot to be released. It should return `:ok` on success. When a plot is released, the id is not re-used, it is used as a unique identifier only. + +```elixir +CommunityGarden.release(pid, 1) +# => :ok +CommunityGarden.list_registrations(pid) +# => [] +``` + +## 5. Get a registered plot + +Implement the `CommunityGarden.get_registration/2` function. It should receive the `pid` and `id` of the plot to be checked. It should return the plot if it is registered, and `:not_found` if it is unregistered. + +```elixir +CommunityGarden.get_registration(pid, 1) +# => %Plot{plot_id: 1, registered_to: "Emma Balan"} +CommunityGarden.get_registration(pid, 7) +# => {:not_found, "plot is unregistered"} +``` + +## Source + +### Created by + +- @neenjaw + +### Contributed to by + +- @angelikatyborska +- @jrr +- @efx +- @justin-m-morgan +- @cr0t \ No newline at end of file diff --git a/elixir/community-garden/lib/community_garden.ex b/elixir/community-garden/lib/community_garden.ex new file mode 100644 index 0000000..bd3ca75 --- /dev/null +++ b/elixir/community-garden/lib/community_garden.ex @@ -0,0 +1,38 @@ +# Use the Plot struct as it is provided +defmodule Plot do + @enforce_keys [:plot_id, :registered_to] + defstruct [:plot_id, :registered_to] +end + +defmodule CommunityGarden do + def start(), + do: Agent.start(fn -> %{index: 0, plots: []} end) + + def list_registrations(pid), + do: Agent.get(pid, fn %{plots: plots} -> plots end) + + def register(pid, register_to), + do: + Agent.get_and_update(pid, fn %{plots: plots, index: counter} -> + index = counter + 1 + plot = %Plot{plot_id: index, registered_to: register_to} + {plot, %{plots: [plot | plots], index: index}} + end) + + def release(pid, plot_id), + do: + Agent.cast(pid, fn %{plots: plots} = state -> + %{state | plots: Enum.reject(plots, fn element -> compare(element, plot_id) end)} + end) + + def get_registration(pid, plot_id) do + list_registrations(pid) + |> Enum.find( + {:not_found, "plot is unregistered"}, + fn element -> compare(element, plot_id) end + ) + end + + defp compare(%Plot{plot_id: element_id}, plot_id) when element_id == plot_id, do: true + defp compare(_element, _plot_id), do: false +end diff --git a/elixir/community-garden/mix.exs b/elixir/community-garden/mix.exs new file mode 100644 index 0000000..9577ef2 --- /dev/null +++ b/elixir/community-garden/mix.exs @@ -0,0 +1,28 @@ +defmodule CommunityGarden.MixProject do + use Mix.Project + + def project do + [ + app: :community_garden, + version: "0.1.0", + # elixir: "~> 1.10", + 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 diff --git a/elixir/community-garden/test/community_garden_test.exs b/elixir/community-garden/test/community_garden_test.exs new file mode 100644 index 0000000..5de3344 --- /dev/null +++ b/elixir/community-garden/test/community_garden_test.exs @@ -0,0 +1,131 @@ +defmodule CommunityGardenTest do + use ExUnit.Case + + @tag task_id: 1 + test "start returns an alive pid" do + assert {:ok, pid} = CommunityGarden.start() + assert Process.alive?(pid) + end + + @tag task_id: 2 + test "when started, the registry is empty" do + assert {:ok, pid} = CommunityGarden.start() + assert [] == CommunityGarden.list_registrations(pid) + end + + @tag task_id: 3 + test "can register a new plot" do + assert {:ok, pid} = CommunityGarden.start() + assert %Plot{} = CommunityGarden.register(pid, "Johnny Appleseed") + end + + @tag task_id: 3 + test "maintains a registry of plots" do + assert {:ok, pid} = CommunityGarden.start() + assert %Plot{} = plot = CommunityGarden.register(pid, "Johnny Appleseed") + assert [plot] == CommunityGarden.list_registrations(pid) + end + + @tag task_id: 3 + test "the first plot has an id of 1" do + assert {:ok, pid} = CommunityGarden.start() + plot = CommunityGarden.register(pid, "Johnny Appleseed") + assert plot.plot_id == 1 + end + + @tag task_id: 3 + test "registered plots have incremental unique id" do + assert {:ok, pid} = CommunityGarden.start() + plot_1 = CommunityGarden.register(pid, "Johnny Appleseed") + plot_2 = CommunityGarden.register(pid, "Frederick Law Olmsted") + plot_3 = CommunityGarden.register(pid, "Lancelot (Capability) Brown") + + assert plot_1.plot_id == 1 + assert plot_2.plot_id == 2 + assert plot_3.plot_id == 3 + end + + @tag task_id: 3 + test "registered plots have incremental unique id when registered concurrently" do + {:ok, pid} = CommunityGarden.start() + + total_plots = 20 + test_process_pid = self() + + Enum.each(1..total_plots, fn n -> + spawn(fn -> + plot = CommunityGarden.register(pid, "Mary Bumblebee #{n}") + send(test_process_pid, {n, plot}) + end) + end) + + plot_ids = + Enum.map(1..total_plots, fn n -> + receive do + {^n, plot} -> plot.plot_id + after + 100 -> nil + end + end) + + assert Enum.sort(plot_ids) == Enum.to_list(1..total_plots) + end + + @tag task_id: 4 + test "can release a plot" do + assert {:ok, pid} = CommunityGarden.start() + assert %Plot{} = plot = CommunityGarden.register(pid, "Johnny Appleseed") + assert :ok = CommunityGarden.release(pid, plot.plot_id) + assert [] == CommunityGarden.list_registrations(pid) + end + + @tag task_id: 4 + test "do not re-use id of released plots" do + assert {:ok, pid} = CommunityGarden.start() + + plot_1 = CommunityGarden.register(pid, "Keanu Reeves") + plot_2 = CommunityGarden.register(pid, "Thomas A. Anderson") + + assert plot_1.plot_id == 1 + assert plot_2.plot_id == 2 + + CommunityGarden.release(pid, plot_1.plot_id) + CommunityGarden.release(pid, plot_2.plot_id) + + plot_3 = CommunityGarden.register(pid, "John Doe") + plot_4 = CommunityGarden.register(pid, "Jane Doe") + + assert plot_3.plot_id == 3 + assert plot_4.plot_id == 4 + end + + @tag task_id: 4 + test "release only one plot at time" do + assert {:ok, pid} = CommunityGarden.start() + + plot_1 = CommunityGarden.register(pid, "Keanu Reeves") + plot_2 = CommunityGarden.register(pid, "Thomas A. Anderson") + + assert plot_1.plot_id == 1 + assert plot_2.plot_id == 2 + + CommunityGarden.release(pid, plot_1.plot_id) + + assert [^plot_2] = CommunityGarden.list_registrations(pid) + end + + @tag task_id: 5 + test "can get registration of a registered plot" do + assert {:ok, pid} = CommunityGarden.start() + assert %Plot{} = plot = CommunityGarden.register(pid, "Johnny Appleseed") + assert %Plot{} = registered_plot = CommunityGarden.get_registration(pid, plot.plot_id) + assert registered_plot.plot_id == plot.plot_id + assert registered_plot.registered_to == "Johnny Appleseed" + end + + @tag task_id: 5 + test "return not_found when attempt to get registration of an unregistered plot" do + assert {:ok, pid} = CommunityGarden.start() + assert {:not_found, "plot is unregistered"} = CommunityGarden.get_registration(pid, 1) + end +end diff --git a/elixir/community-garden/test/test_helper.exs b/elixir/community-garden/test/test_helper.exs new file mode 100644 index 0000000..e8677a3 --- /dev/null +++ b/elixir/community-garden/test/test_helper.exs @@ -0,0 +1,2 @@ +ExUnit.start() +ExUnit.configure(exclude: :pending, trace: true, seed: 0)