Add GH Workflow for CI Tests (#10392)

Co-authored-by: Cody Robibero <cody@robibe.ro>

.github/workflows/ci-tests.yml

@@ -0,0 +1,50 @@
+name: Tests
+on:
+  push:
+    branches:
+      - master
+  # Run tests against the forked branch, but
+  # do not allow access to secrets
+  # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#workflows-in-forked-repositories
+  pull_request:
+
+env:
+  SDK_VERSION: "7.0.x"
+
+jobs:
+  run-tests:
+    strategy:
+      matrix:
+        os: ["ubuntu-latest", "macos-latest", "windows-latest"]
+
+    runs-on: "${{ matrix.os }}"
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-dotnet@v3
+        with:
+          dotnet-version: ${{ env.SDK_VERSION }}
+
+      - name: Run DotNet CLI Tests
+        run: >
+          dotnet test Jellyfin.sln
+          --configuration Release
+          --collect:"XPlat Code Coverage"
+          --settings tests/coverletArgs.runsettings
+          --verbosity minimal
+
+      - name: Merge code coverage results
+        uses: danielpalme/ReportGenerator-GitHub-Action@5
+        with:
+          reports: "**/coverage.cobertura.xml"
+          targetdir: "merged/"
+          reporttypes: "Cobertura"
+
+      # TODO - which action / tool to use to publish code coverage results?
+      # - name: Publish code coverage results
+
+      - name: Publish OpenAPI Artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: "OpenAPI Spec"
+          path: "tests/Jellyfin.Server.Integration.Tests/bin/Release/net*/openapi.json"