ci: 👷 add Elixir CI

Author: maxbarsukov

.github/workflows/elixir.yml

@@ -0,0 +1,81 @@
+name: Elixir CI
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - ".github/workflows/*"
+      - "**/*.ex"
+      - "**/*.exs"
+      - "**/*.eex"
+      - "mix.lock"
+      - "coveralls.json"
+  pull_request:
+    branches:
+      - master
+    paths:
+      - ".github/workflows/*"
+      - "**/*.ex"
+      - "**/*.exs"
+      - "**/*.eex"
+      - "mix.lock"
+      - "coveralls.json"
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Elixir
+        uses: erlef/setup-beam@v1
+        with:
+          otp-version: '27.0.1'
+          elixir-version: '1.17.2'
+
+      - name: Restore deps cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            deps
+            _build
+          key: ${{ runner.os }}-deps-${{ hashFiles('**/mix.lock') }}-git-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-deps-${{ hashFiles('**/mix.lock') }}
+            ${{ runner.os }}-deps
+
+      - name: Install package dependencies
+        run: mix deps.get
+
+      - name: Remove compiled application files
+        run: mix clean
+
+      - name: Compile dependencies
+        run: mix compile
+        env:
+          MIX_ENV: test
+
+      - name: Run tests
+        run: mix test --trace
+        env:
+          MIX_ENV: test
+
+      - name: Check code coverage
+        run: mix coveralls
+        env:
+          MIX_ENV: test
+
+      - name: Upload coverage to coveralls
+        run: mix coveralls.github
+        env:
+          MIX_ENV: test
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Check code formatting
+        run: mix check
+
+      - name: Run Credo linter
+        run: mix credo --strict