From f9559309930d90d8403c573ac2aab6216e1acf94 Mon Sep 17 00:00:00 2001
From: jaeyson <hello@jaeyson.dev>
Date: Fri, 12 Apr 2024 17:38:59 +0800
Subject: [PATCH] Move benchmark as a mix task

---
 .github/dependabot.yml                        |  14 +++
 .github/workflows/ci.yml                      |  30 +++--
 .github/workflows/hex.yml                     |  28 +++++
 .gitignore                                    |   3 +
 .iex.exs                                      |   2 +-
 CHANGELOG.md                                  |   8 +-
 README.md                                     |  26 ++--
 coveralls.json                                |  13 +-
 lib/freecodecamp_elixir/algo_projects.ex      |   6 -
 lib/freecodecamp_elixir/basic_algo.ex         |   4 +-
 .../benchmarks/basic_algo.ex                  |  95 ++++++++------
 .../benchmarks/intermediate_algo.ex           |  43 ++++---
 lib/mix/tasks/benchmark.ex                    | 119 ++++++++++++++++++
 lib/mix/tasks/precommit.ex                    |  14 ++-
 lib/mix/tasks/selective_test.ex               |  18 ++-
 mix.exs                                       |   8 +-
 mix.lock                                      |  28 ++---
 17 files changed, 333 insertions(+), 126 deletions(-)
 create mode 100644 .github/dependabot.yml
 create mode 100644 .github/workflows/hex.yml
 delete mode 100644 lib/freecodecamp_elixir/algo_projects.ex
 rename benchmarks/basic_algo.exs => lib/freecodecamp_elixir/benchmarks/basic_algo.ex (80%)
 rename benchmarks/intermediate_algo.exs => lib/freecodecamp_elixir/benchmarks/intermediate_algo.ex (73%)
 create mode 100644 lib/mix/tasks/benchmark.ex

diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..8125f4b
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,14 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: "mix" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "weekly"
+    labels:
+      - "hex"
+      - "dependencies"
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b89ffad..254de24 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,16 +18,20 @@ jobs:
     strategy:
       matrix:
         include:
-          # - elixir: 1.11.x
-          #   otp: 22
-          # - elixir: 1.11.x
-          #   otp: 23
-          # - elixir: 1.12.x
-          #   otp: 23
-          # - elixir: 1.13.x
-          #   otp: 24
+          - elixir: 1.11.x
+            otp: 22
+          - elixir: 1.11.x
+            otp: 23
+          - elixir: 1.12.x
+            otp: 23
+          - elixir: 1.13.x
+            otp: 24
           - elixir: 1.14.x
             otp: 25
+          - elixir: 1.15.x
+            otp: 26
+          - elixir: 1.16.x
+            otp: 26
             warnings_as_errors: true
             static_analysis: true
     env:
@@ -38,7 +42,7 @@ jobs:
     if: "!contains(github.event.head_commit.message, '[skip ci]')"
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Setup Erlang/OTP & Elixir
         uses: erlef/setup-beam@v1
@@ -47,7 +51,7 @@ jobs:
           elixir-version: ${{ matrix.elixir }}
 
       - name: Cache artifacts
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: |
             deps
@@ -73,9 +77,3 @@ jobs:
         run: mix coveralls.github
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Publish to Hex
-        if: "contains(github.event.head_commit.message, '[publish to hex]')"
-        run: |
-          mix hex.config api_key ${{ secrets.HEX_API_KEY }}
-          mix hex.publish --yes
diff --git a/.github/workflows/hex.yml b/.github/workflows/hex.yml
new file mode 100644
index 0000000..9049e3e
--- /dev/null
+++ b/.github/workflows/hex.yml
@@ -0,0 +1,28 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+
+jobs:
+  check_commit_message:
+    name: skips CI and prints cli message, without fail build badge
+    runs-on: ubuntu-latest
+    if: "contains(github.event.head_commit.message, '[skip ci]')"
+    steps:
+      - run: echo "no need to build, based from commit message"
+        
+  publish_to_hex:
+    name: "Publish to Hex"
+    runs-on: ubuntu-latest
+
+    # doesn't contain "ci skip" in commit message
+    if: "!contains(github.event.head_commit.message, '[skip ci]')"
+    steps:
+      run: |
+        mix hex.config api_key ${{ secrets.HEX_API_KEY }}
+        mix hex.publish --yes
diff --git a/.gitignore b/.gitignore
index c570a3b..2b35ba7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,9 @@ sample-*.tar
 # Temporary files, for example, from tests.
 /tmp/
 
+# Benchmarks from benchee
+/benchmarks/
+
 .elixir_ls
 
 .DS_Store
diff --git a/.iex.exs b/.iex.exs
index abbc273..3bcce40 100644
--- a/.iex.exs
+++ b/.iex.exs
@@ -1,5 +1,5 @@
-alias FreecodecampElixir.AlgoProjects
 alias FreecodecampElixir.BasicAlgo
 alias FreecodecampElixir.IntermediateAlgo
+alias FreecodecampElixir.Benchmarks
 
 require Logger
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e52dc07..dd12fe2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 0.2.0 (2024.12.04)
+
+- Benchmarks as mix task
+- Bump dependencies' versions
+- Tidy docs
+
 ## 0.1.0 (2022.09.04)
 
-* Initial release
+- Initial release
diff --git a/README.md b/README.md
index ec4f581..dbcdb8a 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 Solving exercises from Freecodecamp.org using Elixir programming language. Includes benchmarks and tests for every functions.
 
 [//]: # "Badges"
+
 [![Last Commit][commit-badge]](https://github.com/jaeyson/freecodecamp_elixir/commit/main)
 [![Commit activity][pulse-badge]](https://github.com/jaeyson/freecodecamp_elixir/pulse)
 [![Dependabot][dependabot-badge]](https://github.com/jaeyson/freecodecamp_elixir/pulls/app%2Fdependabot)
@@ -112,7 +113,6 @@ mix selective_test basic_algo intermediate_algo
 
 # basic_algo        = Basic Algorithm Scripting
 # intermediate_algo = Intermediate Algorithm Scripting
-# algo_projects     = Algorithm Projects
 ```
 
 ## Generate `HTML` Docs
@@ -124,22 +124,22 @@ mix docs
 
 ## Benchmarks (using Benchee)
 
-If you want to benchmark a specific function:
-
 ```bash
-# NOTE: file path is at
-# freecodecamp_elixir/benchmarks/basic_algo.exs
+# view benchmark commands
+mix help benchmark
+```
 
-# Example: change the function name from
-# "mutation" to "repeat_string"
-# BasicAlgo.run("mutation", HTML)
-# or uncomment lines to use that instead
-BasicAlgo.run("repeat_string", HTML)
+```bash
+# list available functions
+mix benchmark --list
+```
 
-# you can use the default formatter (console)
-BasicAlgo.run("repeat_string", Console)
+```bash
+# specific function
+mix benchmark mutation
 ```
 
 ```bash
-mix run benchmarks/basic_algo.exs
+# benchmark results saved as html in "benchmarks/" directory
+mix benchmark mutation --html
 ```
diff --git a/coveralls.json b/coveralls.json
index f6d4e57..ae89bc1 100644
--- a/coveralls.json
+++ b/coveralls.json
@@ -1,9 +1,6 @@
 {
-    "skip_files": [
-        "benchmarks/",
-        "lib/mix/"
-    ],
-    "terminal_options": {
-        "file_column_width": 60
-    }
-}
\ No newline at end of file
+  "skip_files": ["lib/freecodecamp_elixir/benchmarks/", "lib/mix/"],
+  "terminal_options": {
+    "file_column_width": 60
+  }
+}
diff --git a/lib/freecodecamp_elixir/algo_projects.ex b/lib/freecodecamp_elixir/algo_projects.ex
deleted file mode 100644
index 83beba0..0000000
--- a/lib/freecodecamp_elixir/algo_projects.ex
+++ /dev/null
@@ -1,6 +0,0 @@
-defmodule FreecodecampElixir.AlgoProjects do
-  @moduledoc """
-  Documentation for Freecodecamp ([Algorithm Projects](https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/#javascript-algorithms-and-data-structures-projects)).
-  """
-  @moduledoc since: "0.1.0"
-end
diff --git a/lib/freecodecamp_elixir/basic_algo.ex b/lib/freecodecamp_elixir/basic_algo.ex
index d897761..2cab885 100644
--- a/lib/freecodecamp_elixir/basic_algo.ex
+++ b/lib/freecodecamp_elixir/basic_algo.ex
@@ -284,8 +284,8 @@ defmodule FreecodecampElixir.BasicAlgo do
   end
 
   @spec do_get_index_to_ins(non_neg_integer | nil) :: non_neg_integer
-  def do_get_index_to_ins(nil), do: 0
-  def do_get_index_to_ins(result), do: result
+  defp do_get_index_to_ins(nil), do: 0
+  defp do_get_index_to_ins(result), do: result
 
   @doc """
   Check if a string (first argument, `string`) ends with the
diff --git a/benchmarks/basic_algo.exs b/lib/freecodecamp_elixir/benchmarks/basic_algo.ex
similarity index 80%
rename from benchmarks/basic_algo.exs
rename to lib/freecodecamp_elixir/benchmarks/basic_algo.ex
index 9c51a16..dbc15d9 100644
--- a/benchmarks/basic_algo.exs
+++ b/lib/freecodecamp_elixir/benchmarks/basic_algo.ex
@@ -1,11 +1,26 @@
-defmodule Benchmark.BasicAlgo do
+defmodule FreecodecampElixir.Benchmarks.BasicAlgo do
+  alias Benchee.Formatters.Console
+  alias Benchee.Formatters.HTML
   alias FreecodecampElixir.BasicAlgo
+  @moduledoc false
+
+  # NOTE: We can't use apply/3 here to run a number of
+  # arbitrary functions in order to minimize the use
+  # of atoms. So we listed all (and future) functions.
+
+  @spec run(String.t(), String.t()) :: module()
+  def run(function_name, formatter \\ "--console") do
+    formatter =
+      case String.downcase(formatter) do
+        "--console" -> Console
+        "--html" -> HTML
+      end
 
-  @spec run(String.t(), module(), any()) :: module()
-  def run(function_name, formatter, args \\ nil),
-    do: __MODULE__ |> apply(String.to_atom(function_name), [formatter, args])
+    do_run(function_name, formatter)
+  end
 
   # set config for benchmark here
+  @spec generic_benchee(map(), HTML | Console, (any() -> any())) :: Benchee.Suite.t()
   defp generic_benchee(map, formatter, before_each_function) do
     Benchee.run(
       map,
@@ -17,8 +32,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec mutation(module(), any()) :: module()
-  def mutation(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("mutation", formatter) do
     generic_benchee(
       %{
         "mutation: Enum.filter" => fn {string1, string2} ->
@@ -38,8 +53,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec truncate_string(module(), any()) :: module()
-  def truncate_string(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("truncate_string", formatter) do
     generic_benchee(
       %{
         "BasicAlgo.truncate_string" => fn {string, pos} ->
@@ -62,8 +77,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec get_index_to_ins(module(), any()) :: module()
-  def get_index_to_ins(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("get_index_to_ins", formatter) do
     generic_benchee(
       %{
         "get_index_to_ins: List comprehension" => fn {list_int, value} ->
@@ -83,8 +98,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec factorialize(module(), any()) :: module()
-  def factorialize(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("factorialize", formatter) do
     generic_benchee(
       %{
         "factorialize: Enum.filter and tco function" => &BasicAlgo.factorialize/1,
@@ -95,8 +110,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec reverse_string(module(), any()) :: module()
-  def reverse_string(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("reverse_string", formatter) do
     generic_benchee(
       %{
         "reverse_string: Pattern matching" => &BasicAlgo.reverse_string/1,
@@ -107,8 +122,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec reverse_string(module(), any()) :: module()
-  def find_longest_word_length(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("find_longest_word_length", formatter) do
     generic_benchee(
       %{
         "find_longest_word_length: Enum.max_by" => &BasicAlgo.find_longest_word_length/1,
@@ -119,8 +134,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec largest_of_four(module(), any()) :: module()
-  def largest_of_four(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("largest_of_four", formatter) do
     list_int =
       -10_000..10_000
       |> StreamData.integer()
@@ -137,8 +152,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec confirm_ending(module(), any()) :: module()
-  def confirm_ending(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("confirm_ending", formatter) do
     generic_benchee(
       %{
         "confirm_ending: String.ends_with?" => fn {str_one, str_two} ->
@@ -158,8 +173,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec find_element(module(), any()) :: module()
-  def find_element(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("find_element", formatter) do
     generic_benchee(
       %{
         "find_element: Enum.find" => fn list ->
@@ -177,8 +192,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec title_case(module(), any()) :: module()
-  def title_case(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("title_case", formatter) do
     generic_benchee(
       %{
         "title_case: BasicAlgo.title_case" => fn string ->
@@ -193,8 +208,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec franken_splice(module(), any()) :: module()
-  def franken_splice(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("franken_splice", formatter) do
     generic_benchee(
       %{
         "franken_splice: BasicAlgo.franken_splice" => fn {list_a, list_b, int} ->
@@ -218,8 +233,8 @@ defmodule Benchmark.BasicAlgo do
     )
   end
 
-  @spec chunk_array_in_groups(module(), any()) :: module()
-  def chunk_array_in_groups(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("chunk_array_in_groups", formatter) do
     generic_benchee(
       %{
         "chunk_array_in_groups: BasicAlgo.chunk_array_in_groups" => fn {list, size} ->
@@ -374,32 +389,32 @@ defmodule Benchmark.BasicAlgo do
   end
 
   @spec title_case_gen(String.t()) :: String.t()
-  def title_case_gen(string) do
+  defp title_case_gen(string) do
     ~w(#{string})
     |> Enum.map_join(" ", &(String.downcase(&1) |> String.capitalize()))
   end
 
   @spec franken_splice_gen_v1(Enumerable.t(), Enumerable.t(), integer) :: Enumerable.t()
-  def franken_splice_gen_v1([], [], _el), do: []
+  defp franken_splice_gen_v1([], [], _el), do: []
 
-  def franken_splice_gen_v1(list_one, list_two, el) do
+  defp franken_splice_gen_v1(list_one, list_two, el) do
     List.insert_at(list_two, el, list_one) |> List.flatten()
   end
 
   @spec franken_splice_gen_v2(Enumerable.t(), Enumerable.t(), integer) :: Enumerable.t()
-  def franken_splice_gen_v2(list_one, list_two, -1) do
+  defp franken_splice_gen_v2(list_one, list_two, -1) do
     {head, tails} = Enum.split(list_two, length(list_two))
     [head | [list_one | [tails]]] |> :lists.flatten()
   end
 
-  def franken_splice_gen_v2(list_one, list_two, el) when el < -1 do
+  defp franken_splice_gen_v2(list_one, list_two, el) when el < -1 do
     {head, tails} = Enum.split(list_two, el + 1)
 
     do_franken_splice(list_one, head, tails)
     |> :lists.flatten()
   end
 
-  def franken_splice_gen_v2(list_one, list_two, el) do
+  defp franken_splice_gen_v2(list_one, list_two, el) do
     {head, tails} = Enum.split(list_two, el)
 
     do_franken_splice(list_one, head, tails)
@@ -411,19 +426,19 @@ defmodule Benchmark.BasicAlgo do
   end
 
   @spec chunk_array_in_groups_gen(Enumerable.t(), integer) :: list(Enumerable.t())
-  def chunk_array_in_groups_gen([], _size), do: []
-  def chunk_array_in_groups_gen(list, size) when size < 1, do: list
+  defp chunk_array_in_groups_gen([], _size), do: []
+  defp chunk_array_in_groups_gen(list, size) when size < 1, do: list
 
-  def chunk_array_in_groups_gen(list, size) do
+  defp chunk_array_in_groups_gen(list, size) do
     Enum.chunk_every(list, size)
   end
 end
 
-alias Benchmark.BasicAlgo
-alias Benchee.Formatters.{HTML, Console}
+# alias Benchmark.BasicAlgo
+# alias Benchee.Formatters.{HTML, Console}
 
 # BasicAlgo.run("mutation", HTML)
-BasicAlgo.run("chunk_array_in_groups", Console)
+# BasicAlgo.run("chunk_array_in_groups", Console)
 
 # Available functions (uncomment above):
 #   - mutation
diff --git a/benchmarks/intermediate_algo.exs b/lib/freecodecamp_elixir/benchmarks/intermediate_algo.ex
similarity index 73%
rename from benchmarks/intermediate_algo.exs
rename to lib/freecodecamp_elixir/benchmarks/intermediate_algo.ex
index d4af275..07711e2 100644
--- a/benchmarks/intermediate_algo.exs
+++ b/lib/freecodecamp_elixir/benchmarks/intermediate_algo.ex
@@ -1,14 +1,27 @@
-defmodule Benchmark.IntermediateAlgo do
+defmodule FreecodecampElixir.Benchmarks.IntermediateAlgo do
+  alias Benchee.Formatters.Console
+  alias Benchee.Formatters.HTML
   alias FreecodecampElixir.IntermediateAlgo
+  @moduledoc false
 
-  @spec run(String.t(), module(), any()) :: module()
-  def run(function_name, formatter, args \\ nil),
-    do: __MODULE__ |> apply(String.to_atom(function_name), [formatter, args])
+  # NOTE: We can't use apply/3 here to run a number of
+  # arbitrary functions in order to minimize the use
+  # of atoms. So we listed all (and future) functions.
+
+  @spec run(String.t(), String.t()) :: module()
+  def run(function_name, formatter \\ "--console") do
+    case formatter do
+      "--console" -> Console
+      "--html" -> HTML
+    end
+
+    do_run(function_name, formatter)
+  end
 
   # set config for benchmark here
-  defp generic_benchee(jobs, formatter, before_each_function) do
+  defp generic_benchee(map, formatter, before_each_function) do
     Benchee.run(
-      jobs,
+      map,
       before_each: before_each_function,
       time: 5,
       memory_time: 2,
@@ -17,8 +30,8 @@ defmodule Benchmark.IntermediateAlgo do
     )
   end
 
-  @spec sum_all(module(), any()) :: module()
-  def sum_all(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("sum_all", formatter) do
     generic_benchee(
       %{
         "IntermediateAlgo.sum_all" => fn {int1, int2} ->
@@ -44,8 +57,8 @@ defmodule Benchmark.IntermediateAlgo do
     )
   end
 
-  @spec diff_list(module(), any()) :: module()
-  def diff_list(formatter, _args) do
+  @spec do_run(String.t(), module()) :: module()
+  defp do_run("diff_list", formatter) do
     generic_benchee(
       %{
         "IntermediateAlgo.diff_list" => fn {list1, list2} ->
@@ -96,9 +109,9 @@ defmodule Benchmark.IntermediateAlgo do
   end
 
   @spec sum_all_gen_v3(list(integer)) :: integer
-  def sum_all_gen_v3([0, 0]), do: 0
+  defp sum_all_gen_v3([0, 0]), do: 0
 
-  def sum_all_gen_v3([num_one, num_two] = _list) do
+  defp sum_all_gen_v3([num_one, num_two] = _list) do
     for(x <- num_one..num_two, do: x)
     |> do_sum_all_v3()
   end
@@ -119,11 +132,11 @@ defmodule Benchmark.IntermediateAlgo do
   end
 end
 
-alias Benchmark.IntermediateAlgo
-alias Benchee.Formatters.{HTML, Console}
+# alias Benchmark.IntermediateAlgo
+# alias Benchee.Formatters.{HTML, Console}
 
 # IntermediateAlgo.run("mutation", HTML)
-IntermediateAlgo.run("diff_list", Console)
+# IntermediateAlgo.run("diff_list", Console)
 
 # Available functions (uncomment above):
 #   - diff_list
diff --git a/lib/mix/tasks/benchmark.ex b/lib/mix/tasks/benchmark.ex
new file mode 100644
index 0000000..c9a3fe4
--- /dev/null
+++ b/lib/mix/tasks/benchmark.ex
@@ -0,0 +1,119 @@
+defmodule Mix.Tasks.Benchmark do
+  @moduledoc """
+  ## Usage
+
+  `mix benchmark [module, ...] [options] `
+
+  Running e.g. `mix selective_test basic_algo` will
+  only include tests from `test/basic_algo_test.exs`.
+  Note: these command is not to be ran inside `iex`,
+  rather run this in your OS shell.
+
+  To view this via terminal:
+  ```bash
+  mix help benchmark
+  ```
+
+  ## Options
+
+  - `--list`: Lists available functions
+  - `--console`: Outputs benchmark result in terminal (Default).
+  - `--html`: Outputs benchmark as html doc
+
+  ## Example
+
+  ```bash
+  # list available functions
+  mix benchmark --list
+  ```
+
+  ```bash
+  # specific function
+  mix benchmark mutation
+  ```
+
+  ```bash
+  # benchmark specific function, export to html
+  mix benchmark mutation --html
+  ```
+
+  """
+  @moduledoc since: "0.2.0"
+  @shortdoc "Benchmarks a specific function"
+
+  use Mix.Task
+
+  @formatter ~w(--html --console)
+  @benchmarks "Benchmarks"
+
+  @impl Mix.Task
+  @spec run([String.t()]) :: IO.puts()
+  def run(["--list"]) do
+    functions = list_available_functions() |> Map.values() |> List.flatten()
+    available_functions = Enum.map_join(functions, "\n", &("- " <> to_string(&1)))
+    specific_function = Enum.random(functions)
+
+    """
+    Here's the list of available modules:
+    #{available_functions}
+
+    To run specific module:
+    $ mix benchmark #{specific_function}
+
+    To run and export result to html:
+    $ mix benchmark #{specific_function} --html
+    """
+    |> IO.puts()
+  end
+
+  @spec run(list(String.t())) :: IO.puts() | Benchee.Suite.t()
+  def run(args) do
+    all_fns = list_available_functions() |> Map.values() |> List.flatten()
+
+    case Enum.all?(args, &(&1 in all_fns or &1 in @formatter)) do
+      true ->
+        formatter = Enum.find(args, &(&1 in @formatter)) || "console"
+        function = Enum.filter(args, &(&1 in all_fns)) |> hd()
+        mod = find_module(function)
+
+        mod.run(function, formatter)
+
+      false ->
+        IO.puts(~s(Error: invalid arguments. See "mix help benchmark" for instructions))
+    end
+  end
+
+  @spec find_module(String.t()) :: module()
+  defp find_module(function) do
+    {mod, _functions} =
+      list_available_functions()
+      |> Enum.find(fn {_mod, functions} -> function in functions end)
+
+    mod
+  end
+
+  @spec list_available_functions :: %{module() => list(String.t())}
+  defp list_available_functions do
+    {:ok, modules} = :application.get_key(:freecodecamp_elixir, :modules)
+
+    modules
+    |> Enum.filter(fn module ->
+      case Module.split(module) do
+        [_app_name, _namespace] -> true
+        _ -> false
+      end
+    end)
+    |> Enum.group_by(
+      fn module ->
+        [app_name, base] = module |> Module.split()
+        app_name |> Module.concat(@benchmarks) |> Module.concat(base)
+      end,
+      fn module ->
+        module.__info__(:functions) |> Keyword.keys() |> Enum.map(&to_string/1)
+      end
+    )
+    |> Enum.reduce(%{}, fn {module, functions}, acc ->
+      Map.put(acc, module, List.flatten(functions))
+    end)
+  end
+end
diff --git a/lib/mix/tasks/precommit.ex b/lib/mix/tasks/precommit.ex
index 96df0e0..0174c30 100644
--- a/lib/mix/tasks/precommit.ex
+++ b/lib/mix/tasks/precommit.ex
@@ -1,6 +1,8 @@
 defmodule Mix.Tasks.Precommit do
   @moduledoc """
-  Usage: `mix precommit [--force]`
+  ## Usage
+
+  `mix precommit [--force]`
 
   Generates `pre-commit` git hook. Visit [this link](https://git-scm.com/book/en/Customizing-Git-Git-Hooks)
   to know more about git hooks. Add option `--force` to
@@ -8,10 +10,18 @@ defmodule Mix.Tasks.Precommit do
   command is not to be ran inside `iex`, rather run
   this in your OS shell.
 
-  Example:
+  To view this via terminal:
+  ```bash
+  mix help precommit
+  ```
+
+  ## Example
 
   ```bash
   mix precommit
+
+  # force
+  mix precommit --force
   ```
 
   """
diff --git a/lib/mix/tasks/selective_test.ex b/lib/mix/tasks/selective_test.ex
index b3e5c52..669804e 100644
--- a/lib/mix/tasks/selective_test.ex
+++ b/lib/mix/tasks/selective_test.ex
@@ -1,18 +1,28 @@
 defmodule Mix.Tasks.SelectiveTest do
   @moduledoc """
-  Usage: `mix selective_test [module, ...]`
+  ## Usage
+
+  `mix selective_test [module, ...]`
 
   Running e.g. `mix selective_test basic_algo` will
   only include tests from `test/basic_algo_test.exs`.
-  Another way to call it:
-  `mix test --exclude intermediate_algo basic_algo ...`.
   Note: these command is not to be ran inside `iex`,
   rather run this in your OS shell.
 
-  Example:
+  To view this via terminal:
+  ```bash
+  mix help selective_test
+  ```
 
+  ## Example
+
+  Another way to call it:
   ```bash
+  # specific test
   mix selective_test basic_algo
+
+  # two or more
+  mix test --exclude intermediate_algo basic_algo
   ```
 
   """
diff --git a/mix.exs b/mix.exs
index 53939dd..2ce810e 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule FreecodecampElixir.MixProject do
   use Mix.Project
 
-  @version "0.1.0"
+  @version "0.2.0"
   @elixir_version "~> 1.9"
   @source_url "https://github.com/jaeyson/freecodecamp_elixir"
   @coverage_url "https://coveralls.io/github/jaeyson/freecodecamp_elixir"
@@ -42,11 +42,11 @@ defmodule FreecodecampElixir.MixProject do
     [
       # {:dep_from_hexpm, "~> 0.3.0"},
       # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
-      {:stream_data, "~> 0.5.0", only: [:dev, :test]},
+      {:stream_data, "~> 0.6", only: [:dev, :test]},
       {:benchee, "~> 1.0", only: [:dev], runtime: false},
       {:benchee_html, "~> 1.0", only: [:dev], runtime: false},
-      {:ex_doc, "~> 0.28.2", only: [:dev, :test], runtime: false},
-      {:credo, "~> 1.6.4", only: [:dev, :test], runtime: false},
+      {:ex_doc, "~> 0.32", only: :dev, runtime: false},
+      {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
       {:excoveralls, "~> 0.10", only: :test}
     ]
   end
diff --git a/mix.lock b/mix.lock
index fad4189..5c8bfda 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,27 +1,27 @@
 %{
-  "benchee": {:hex, :benchee, "1.1.0", "f3a43817209a92a1fade36ef36b86e1052627fd8934a8b937ac9ab3a76c43062", [:mix], [{:deep_merge, "~> 1.0", [hex: :deep_merge, repo: "hexpm", optional: false]}, {:statistex, "~> 1.0", [hex: :statistex, repo: "hexpm", optional: false]}], "hexpm", "7da57d545003165a012b587077f6ba90b89210fd88074ce3c60ce239eb5e6d93"},
-  "benchee_html": {:hex, :benchee_html, "1.0.0", "5b4d24effebd060f466fb460ec06576e7b34a00fc26b234fe4f12c4f05c95947", [:mix], [{:benchee, ">= 0.99.0 and < 2.0.0", [hex: :benchee, repo: "hexpm", optional: false]}, {:benchee_json, "~> 1.0", [hex: :benchee_json, repo: "hexpm", optional: false]}], "hexpm", "5280af9aac432ff5ca4216d03e8a93f32209510e925b60e7f27c33796f69e699"},
+  "benchee": {:hex, :benchee, "1.3.0", "f64e3b64ad3563fa9838146ddefb2d2f94cf5b473bdfd63f5ca4d0657bf96694", [:mix], [{:deep_merge, "~> 1.0", [hex: :deep_merge, repo: "hexpm", optional: false]}, {:statistex, "~> 1.0", [hex: :statistex, repo: "hexpm", optional: false]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "34f4294068c11b2bd2ebf2c59aac9c7da26ffa0068afdf3419f1b176e16c5f81"},
+  "benchee_html": {:hex, :benchee_html, "1.0.1", "1e247c0886c3fdb0d3f4b184b653a8d6fb96e4ad0d0389267fe4f36968772e24", [:mix], [{:benchee, ">= 0.99.0 and < 2.0.0", [hex: :benchee, repo: "hexpm", optional: false]}, {:benchee_json, "~> 1.0", [hex: :benchee_json, repo: "hexpm", optional: false]}], "hexpm", "b00a181af7152431901e08f3fc9f7197ed43ff50421a8347b0c80bf45d5b3fef"},
   "benchee_json": {:hex, :benchee_json, "1.0.0", "cc661f4454d5995c08fe10dd1f2f72f229c8f0fb1c96f6b327a8c8fc96a91fe5", [:mix], [{:benchee, ">= 0.99.0 and < 2.0.0", [hex: :benchee, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "da05d813f9123505f870344d68fb7c86a4f0f9074df7d7b7e2bb011a63ec231c"},
-  "bunt": {:hex, :bunt, "0.2.1", "e2d4792f7bc0ced7583ab54922808919518d0e57ee162901a16a1b6664ef3b14", [:mix], [], "hexpm", "a330bfb4245239787b15005e66ae6845c9cd524a288f0d141c148b02603777a5"},
+  "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
   "certifi": {:hex, :certifi, "2.9.0", "6f2a475689dd47f19fb74334859d460a2dc4e3252a3324bd2111b8f0429e7e21", [:rebar3], [], "hexpm", "266da46bdb06d6c6d35fde799bcb28d36d985d424ad7c08b5bb48f5b5cdd4641"},
-  "credo": {:hex, :credo, "1.6.6", "f51f8d45db1af3b2e2f7bee3e6d3c871737bda4a91bff00c5eec276517d1a19c", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2.8", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "625520ce0984ee0f9f1f198165cd46fa73c1e59a17ebc520038b8fce056a5bdc"},
+  "credo": {:hex, :credo, "1.7.5", "643213503b1c766ec0496d828c90c424471ea54da77c8a168c725686377b9545", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "f799e9b5cd1891577d8c773d245668aa74a2fcd15eb277f51a0131690ebfb3fd"},
   "deep_merge": {:hex, :deep_merge, "1.0.0", "b4aa1a0d1acac393bdf38b2291af38cb1d4a52806cf7a4906f718e1feb5ee961", [:mix], [], "hexpm", "ce708e5f094b9cd4e8f2be4f00d2f4250c4095be93f8cd6d018c753894885430"},
-  "earmark_parser": {:hex, :earmark_parser, "1.4.26", "f4291134583f373c7d8755566122908eb9662df4c4b63caa66a0eabe06569b0a", [:mix], [], "hexpm", "48d460899f8a0c52c5470676611c01f64f3337bad0b26ddab43648428d94aabc"},
-  "ex_doc": {:hex, :ex_doc, "0.28.5", "3e52a6d2130ce74d096859e477b97080c156d0926701c13870a4e1f752363279", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "d2c4b07133113e9aa3e9ba27efb9088ba900e9e51caa383919676afdf09ab181"},
-  "excoveralls": {:hex, :excoveralls, "0.14.6", "610e921e25b180a8538229ef547957f7e04bd3d3e9a55c7c5b7d24354abbba70", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "0eceddaa9785cfcefbf3cd37812705f9d8ad34a758e513bb975b081dce4eb11e"},
-  "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.39", "424642f8335b05bb9eb611aa1564c148a8ee35c9c8a8bba6e129d51a3e3c6769", [:mix], [], "hexpm", "06553a88d1f1846da9ef066b87b57c6f605552cfbe40d20bd8d59cc6bde41944"},
+  "ex_doc": {:hex, :ex_doc, "0.32.0", "896afb57b1e00030f6ec8b2e19d3ca99a197afb23858d49d94aea673dc222f12", [:mix], [{:earmark_parser, "~> 1.4.39", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.1", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "ed2c3e42c558f49bda3ff37e05713432006e1719a6c4a3320c7e4735787374e7"},
+  "excoveralls": {:hex, :excoveralls, "0.18.1", "a6f547570c6b24ec13f122a5634833a063aec49218f6fff27de9df693a15588c", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "d65f79db146bb20399f23046015974de0079668b9abb2f5aac074d078da60b8d"},
+  "file_system": {:hex, :file_system, "1.0.0", "b689cc7dcee665f774de94b5a832e578bd7963c8e637ef940cd44327db7de2cd", [:mix], [], "hexpm", "6752092d66aec5a10e662aefeed8ddb9531d79db0bc145bb8c40325ca1d8536d"},
   "hackney": {:hex, :hackney, "1.18.1", "f48bf88f521f2a229fc7bae88cf4f85adc9cd9bcf23b5dc8eb6a1788c662c4f6", [:rebar3], [{:certifi, "~>2.9.0", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~>6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~>1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~>1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "a4ecdaff44297e9b5894ae499e9a070ea1888c84afdd1fd9b7b2bc384950128e"},
   "idna": {:hex, :idna, "6.1.1", "8a63070e9f7d0c62eb9d9fcb360a7de382448200fbbd1b106cc96d3d8099df8d", [:rebar3], [{:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "92376eb7894412ed19ac475e4a86f7b413c1b9fbb5bd16dccd57934157944cea"},
-  "jason": {:hex, :jason, "1.3.0", "fa6b82a934feb176263ad2df0dbd91bf633d4a46ebfdffea0c8ae82953714946", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "53fc1f51255390e0ec7e50f9cb41e751c260d065dcba2bf0d08dc51a4002c2ac"},
-  "makeup": {:hex, :makeup, "1.1.0", "6b67c8bc2882a6b6a445859952a602afc1a41c2e08379ca057c0f525366fc3ca", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "0a45ed501f4a8897f580eabf99a2e5234ea3e75a4373c8a52824f6e873be57a6"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.16.0", "f8c570a0d33f8039513fbccaf7108c5d750f47d8defd44088371191b76492b0b", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "28b2cbdc13960a46ae9a8858c4bebdec3c9a6d7b4b9e7f4ed1502f8159f338e7"},
-  "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
+  "jason": {:hex, :jason, "1.4.1", "af1504e35f629ddcdd6addb3513c3853991f694921b1b9368b0bd32beb9f1b63", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "fbb01ecdfd565b56261302f7e1fcc27c4fb8f32d56eab74db621fc154604a7a1"},
+  "makeup": {:hex, :makeup, "1.1.1", "fa0bc768698053b2b3869fa8a62616501ff9d11a562f3ce39580d60860c3a55e", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "5dc62fbdd0de44de194898b6710692490be74baa02d9d108bc29f007783b0b48"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.16.2", "627e84b8e8bf22e60a2579dad15067c755531fea049ae26ef1020cad58fe9578", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "41193978704763f6bbe6cc2758b84909e62984c7752b3784bd3c218bb341706b"},
+  "makeup_erlang": {:hex, :makeup_erlang, "0.1.5", "e0ff5a7c708dda34311f7522a8758e23bfcd7d8d8068dc312b5eb41c6fd76eba", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "94d2e986428585a21516d7d7149781480013c56e30c6a233534bedf38867a59a"},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm", "69b09adddc4f74a40716ae54d140f93beb0fb8978d8636eaded0c31b6f099f16"},
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
-  "nimble_parsec": {:hex, :nimble_parsec, "1.2.3", "244836e6e3f1200c7f30cb56733fd808744eca61fd182f731eac4af635cc6d0b", [:mix], [], "hexpm", "c8d789e39b9131acf7b99291e93dae60ab48ef14a7ee9d58c6964f59efb570b0"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.4.0", "51f9b613ea62cfa97b25ccc2c1b4216e81df970acd8e16e8d1bdc58fef21370d", [:mix], [], "hexpm", "9c565862810fb383e9838c1dd2d7d2c437b3d13b267414ba6af33e50d2d1cf28"},
   "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
   "statistex": {:hex, :statistex, "1.0.0", "f3dc93f3c0c6c92e5f291704cf62b99b553253d7969e9a5fa713e5481cd858a5", [:mix], [], "hexpm", "ff9d8bee7035028ab4742ff52fc80a2aa35cece833cf5319009b52f1b5a86c27"},
-  "stream_data": {:hex, :stream_data, "0.5.0", "b27641e58941685c75b353577dc602c9d2c12292dd84babf506c2033cd97893e", [:mix], [], "hexpm", "012bd2eec069ada4db3411f9115ccafa38540a3c78c4c0349f151fc761b9e271"},
+  "stream_data": {:hex, :stream_data, "0.6.0", "e87a9a79d7ec23d10ff83eb025141ef4915eeb09d4491f79e52f2562b73e5f47", [:mix], [], "hexpm", "b92b5031b650ca480ced047578f1d57ea6dd563f5b57464ad274718c9c29501c"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
 }