Smoke test swiftly on nightly snapshot toolchains

.github/workflows/nightly_snapshot_check.yml

@@ -0,0 +1,28 @@
+name: Smoke Test - Nightly Swift Toolchain
+
+on:
+  schedule:
+    - cron: '30 3 * * *'
+
+env:
+  SWIFTLY_BOOTSTRAP_VERSION: 1.0.0
+
+jobs:
+  tests-selfhosted:
+    name: Test (Smoke Test - Nightly Swift Toolchain) / ${{ matrix.container }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        container: ["ubuntu:20.04", "ubuntu:22.04", "ubuntu:24.04", "redhat/ubi9", "debian:12", "fedora:39"]
+    container:
+      image: ${{ matrix.container }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Prepare the action
+        run: ./scripts/prep-gh-action.sh --install-swiftly --swift-main-snapshot
+      - name: Build and Test
+        # UBI 9 and Ubuntu 20.04 - See https://github.com/swiftlang/swift/issues/80908
+        # UBI 9 - See https://github.com/swiftlang/swift/issues/80909
+        run: bash -c 'if [[ "${{ matrix.container }}" == "redhat/ubi9" ]]; then swiftly run +main-snapshot swift build --build-tests; elif [[ "${{ matrix.container }}" == "ubuntu:20.04" ]]; then swiftly run +main-snapshot swift build --build-tests; else swiftly run +main-snapshot swift test; fi'

scripts/prep-gh-action.sh

@@ -16,6 +16,9 @@ while [ $# -ne 0 ]; do
         --install-swiftly)
             installSwiftly=true
             ;;
+        --swift-main-snapshot)
+            swiftMainSnapshot=true
+            ;;
         *)
             ;;
     esac
@@ -34,23 +37,34 @@ if [ "$installSwiftly" == true ]; then
         echo "PATH=$PATH" >> "$GITHUB_ENV" && echo "SWIFTLY_HOME_DIR=$SWIFTLY_HOME_DIR" >> "$GITHUB_ENV" && echo "SWIFTLY_BIN_DIR=$SWIFTLY_BIN_DIR" >> "$GITHUB_ENV"
     fi
 
-    if [ -f .swift-version ]; then
-        echo "Installing selected swift toolchain"
-        swiftly install --post-install-file=post-install.sh
+    selector=()
+    runSelector=()
+
+    if [ "$swiftMainSnapshot" == true ]; then
+        echo "Installing latest main-snapshot toolchain"
+        selector=("main-snapshot")
+        runSelector=("+main-snapshot")
+    elif [ -f .swift-version ]; then
+        echo "Installing selected swift toolchain from .swift-version file"
+        selector=()
+        runSelector=()
     else
         echo "Installing latest toolchain"
-        swiftly install --post-install-file=post-install.sh latest
+        selector=("latest")
+        runSelector=("+latest")
     fi
 
+    swiftly install --post-install-file=post-install.sh "${selector[@]}"
+
     if [ -f post-install.sh ]; then
         echo "Performing swift toolchain post-installation"
         chmod u+x post-install.sh && ./post-install.sh
     fi
 
     echo "Displaying swift version"
-    swift --version
+    swiftly run "${runSelector[@]}" swift --version
 
-    CC=clang swiftly run "$(dirname "$0")/install-libarchive.sh"
+    CC=clang swiftly run "${runSelector[@]}" "$(dirname "$0")/install-libarchive.sh"
 else
     "$(dirname "$0")/install-libarchive.sh"
 fi