ci: enable mutation testing with muzak pro

.github/workflows/elixir.yml

@@ -24,23 +24,18 @@ jobs:
         include:
           - elixir: 1.9.4
             otp: 22.3
-            check_deps: false
-            check_format: false
           - elixir: 1.10.4
             otp: 22.3
-            check_format: false
           - elixir: 1.11.4
             otp: 23.3
-            check_format: false
           - elixir: 1.12.3
             otp: 24.1
           - elixir: 1.13.0
             otp: 24.1
           - elixir: 1.14.1
-            check_deps: true
-            check_format: true
             otp: 25.1
-
+            check_format: true
+            check_deps: true
 
     steps:
     - uses: actions/checkout@v2

.github/workflows/mutation_testing.yml

@@ -0,0 +1,55 @@
+name: Mutation testing
+
+env:
+  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+on:
+  push:
+    branches: [ "**" ]
+  pull_request:
+    branches: [ "**" ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-20.04
+    name: OTP ${{matrix.otp}} / Elixir ${{matrix.elixir}}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - elixir: 1.14.1
+            otp: 25.1
+
+    steps:
+    - uses: actions/checkout@v3
+      with:
+       fetch-depth: 30
+
+    - name: Set up Elixir
+      uses: erlef/setup-beam@v1
+      with:
+        elixir-version: ${{matrix.elixir}}
+        otp-version: ${{matrix.otp}}
+
+    - name: Restore dependencies cache
+      uses: actions/cache@v2
+      with:
+        path: deps
+        key: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-mix-${{ hashFiles('**/mix.lock') }}
+
+    - name: Install protoc
+      run: |
+        wget https://github.com/protocolbuffers/protobuf/releases/download/v21.4/protoc-21.4-linux-x86_64.zip
+        unzip -d protoc protoc-21.4-linux-x86_64.zip
+        echo "${PWD}/protoc/bin" >> $GITHUB_PATH
+
+    - name: Run mutation testing
+      env:
+        PROTOX_MUZAK_PRO_CREDS: ${{ secrets.PROTOX_MUZAK_PRO_CREDS }}
+        MIX_ENV: test
+      run: |
+        mix local.rebar --force
+        mix local.hex --force
+        mix deps.get
+        mix muzak --profile ci

.muzak.exs

@@ -77,7 +77,6 @@
       end)
       |> Enum.filter(&String.ends_with?(&1, ".ex"))
       |> Enum.map(&{&1, nil})
-      |> IO.inspect()
     end,
 
     # If you would like to run fewer tests for each run, or run them in a certain order, you
@@ -104,30 +103,10 @@
     # being run.
     #
     mutation_filter: fn _ ->
-      split_pattern = ";;;"
-
-      {commits_and_authors, 0} =
-        System.cmd("git", [
-          "log",
-          "--pretty=format:%C(auto)%h#{split_pattern}%an",
-          "--date-order",
-          "-20"
-        ])
-
-      last_commit_by_a_different_author =
-        commits_and_authors
-        |> String.split("\n")
-        |> Enum.map(&String.split(&1, split_pattern))
-        |> Enum.reduce_while(nil, fn
-          [_, author], nil -> {:cont, author}
-          [_, author], author -> {:cont, author}
-          [commit, _], _ -> {:halt, commit}
-        end)
-
-      {diff, 0} = System.cmd("git", ["diff", "-U0", last_commit_by_a_different_author])
+      {diff, 0} = System.cmd("git", ["diff", "HEAD~25"])
 
       # All of this is to parse the git diff output to get the correct files and line numbers
-      # that have changed in the given diff since the last commit by a different author.
+      # that have changed in the given diff since the last 25 commits.
       first = ~r|---\ (a/)?.*|
       second = ~r|\+\+\+\ (b\/)?(.*)|
       third = ~r|@@\ -[0-9]+(,[0-9]+)?\ \+([0-9]+)(,[0-9]+)?\ @@.*|

mix.exs

@@ -17,7 +17,8 @@ defmodule Protox.Mixfile do
       description: description(),
       package: package(),
       dialyzer: [plt_local_path: "priv/plts"],
-      docs: docs()
+      docs: docs(),
+      preferred_cli_env: [muzak: :test]
     ]
   end
 
@@ -49,6 +50,21 @@ defmodule Protox.Mixfile do
       {:poison, "~> 4.0 or ~> 5.0", only: [:test, :dev], optional: true},
       {:propcheck, "~> 1.2", only: [:test, :dev]}
     ]
+    |> maybe_add_muzak_pro()
+  end
+
+  defp maybe_add_muzak_pro(deps) do
+    case System.get_env("PROTOX_MUZAK_PRO_CREDS") do
+      nil ->
+        deps
+
+      creds ->
+        muzak_pro =
+          {:muzak,
+           git: "https://#{creds}@git.devonestes.com/muzak/muzak.git", tag: "1.1.0", only: [:test]}
+
+        [muzak_pro | deps]
+    end
   end
 
   defp description do