Add build matrix and separate compile step

Author: halfdan

.github/workflows/elixir.yml

@@ -7,52 +7,59 @@ name: Elixir CI
 
 on:
   push:
-    branches: [ "master" ]
+    branches: ["master"]
   pull_request:
-    branches: [ "master" ]
+    branches: ["master"]
 
 permissions:
   contents: read
 
 jobs:
   build:
-
     name: Build and test
     runs-on: ubuntu-latest
-
+    strategy:
+      matrix:
+        elixir: ["1.15.8", "1.16.3", "1.17.3", "1.18.2"]
+        otp: ["25.3.2", "26.2.5", "27.2.4"]
+        exclude:
+          - elixir: "1.15.8"
+            otp: "27.2.4"
+          - elixir: "1.16.3"
+            otp: "27.2.4"
     steps:
-    - name: Configure sysctl limits
-      run: |
-        sudo swapoff -a
-        sudo sysctl -w vm.swappiness=1
-        sudo sysctl -w fs.file-max=262144
-        sudo sysctl -w vm.max_map_count=262144
-
-    - name: Runs Elasticsearch
-      uses: elastic/elastic-github-actions/elasticsearch@master
-      with:
-        stack-version: 7.17.16
-        security-enabled: false
-
-    - name: Checkout code
-      uses: actions/checkout@v4
-
-    - name: Set up Elixir
-      uses: erlef/setup-beam@v1
-      with:
-        version-file: .tool-versions
-        version-type: strict
-
-    - name: Restore dependencies cache
-      uses: actions/cache@v3
-      with:
-        path: deps
-        key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
-        restore-keys: ${{ runner.os }}-mix-
-
-    - name: Install dependencies
-      run: mix deps.get
-
-    - name: Run tests
-      run: mix test
+      - name: Configure sysctl limits
+        run: |
+          sudo swapoff -a
+          sudo sysctl -w vm.swappiness=1
+          sudo sysctl -w fs.file-max=262144
+          sudo sysctl -w vm.max_map_count=262144
+
+      - name: Runs Elasticsearch
+        uses: elastic/elastic-github-actions/elasticsearch@master
+        with:
+          stack-version: 7.17.16
+          security-enabled: false
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Elixir
+        uses: erlef/setup-beam@v1
+        with:
+          otp-version: ${{matrix.otp}}
+          elixir-version: ${{matrix.elixir}}
+
+      - name: Restore dependencies cache
+        uses: actions/cache@v3
+        with:
+          path: deps
+          key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
+          restore-keys: ${{ runner.os }}-mix-
 
+      - name: Install dependencies
+        run: mix deps.get
+      - name: Compile
+        run: mix compile --warnings-as-errors
+      - name: Run tests
+        run: mix test