ci: Adds CI

Author: NeedleInAJayStack

.github/workflows/build.yml

@@ -0,0 +1,86 @@
+name: Tests
+
+on:
+  push:
+    branches: [ main ]
+    paths-ignore: [ README.md ]
+  pull_request:
+    branches: [ main ]
+    paths-ignore: [ README.md ]
+  workflow_dispatch:
+
+jobs:
+  formatlint:
+    name: Format linting
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+      - name: Pull formatting docker image
+        run: docker pull ghcr.io/nicklockwood/swiftformat:latest
+      - name: Run format linting
+        run: docker run --rm -v ${{ github.workspace }}:/repo ghcr.io/nicklockwood/swiftformat:latest /repo --lint
+
+  macos:
+    name: Test on macOS
+    runs-on: macos-latest
+    steps:
+    - uses: maxim-lobanov/setup-xcode@v1
+      with:
+        xcode-version: latest-stable
+    - uses: actions/checkout@v3
+    - name: Build and test
+      run: swift test --parallel --enable-test-discovery
+
+  linux:
+    name: Test on Linux
+    runs-on: ubuntu-latest
+    steps:
+    - uses: swift-actions/setup-swift@v2
+    - uses: actions/checkout@v3
+    - name: Test
+      run: swift test --parallel --enable-code-coverage
+    - name: Get test coverage html
+      run: |
+        llvm-cov show \
+          $(swift build --show-bin-path)/GraphQLRxSwiftPackageTests.xctest \
+          --instr-profile $(swift build --show-bin-path)/codecov/default.profdata \
+          --ignore-filename-regex="\.build|Tests" \
+          --format html \
+          --output-dir=.test-coverage
+    - name: Upload test coverage html
+      uses: actions/upload-artifact@v3
+      with:
+        name: test-coverage-report
+        path: .test-coverage
+
+  backcompat-ubuntu-22_04:
+    name: Test Swift ${{ matrix.swift }} on Ubuntu 22.04
+    runs-on: ubuntu-22.04
+    strategy:
+      matrix:
+        swift: ["5.7", "5.8", "5.9", "5.10", "6.0"]
+    steps:
+    - uses: swift-actions/setup-swift@v2
+      with:
+        swift-version: ${{ matrix.swift }}
+    - uses: actions/checkout@v3
+    - name: Test
+      run: swift test --parallel
+
+  # Swift versions older than 5.7 don't have builds for 22.04. https://www.swift.org/download/ 
+  backcompat-ubuntu-20_04:
+    name: Test Swift ${{ matrix.swift }} on Ubuntu 20.04
+    runs-on: ubuntu-20.04
+    strategy:
+      matrix:
+        swift: ["5.4", "5.5", "5.6"]
+    steps:
+    - uses: swift-actions/setup-swift@v2
+      with:
+        swift-version: ${{ matrix.swift }}
+    - uses: actions/checkout@v3
+    - name: Test
+      run: swift test --parallel