test: Graalvm smoke test

.github/workflows/pull_requests.yml

@@ -29,8 +29,31 @@ jobs:
           flag-name: run-jvm-${{ join(matrix.*, '-') }}
           parallel: true
           base-path: src/main/java
+
+  graalvm-native-image:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup GraalVM
+        uses: graalvm/setup-graalvm@v1
+        with:
+          distribution: graalvm
+          java-version: "21"
+          components: native-image
+          cache: maven
+      - name: Compile smoke test
+        run: ./mvnw -B -DskipTests test-compile dependency:build-classpath -Dmdep.outputFile=target/test-classpath.txt
+      - name: Build native image
+        run: |
+          native-image --no-fallback --enable-url-protocols=http \
+            -cp "target/classes:target/test-classes:$(cat target/test-classpath.txt)" \
+            io.getunleash.repository.GraalVmHttpFeatureFetcherSmoke \
+            target/graalvm-http-feature-fetcher-smoke
+      - name: Run native image smoke test
+        run: ./target/graalvm-http-feature-fetcher-smoke
   finish:
-    needs: build
+    needs: [build, graalvm-native-image]
     if: ${{ always() }}
     runs-on: ubuntu-latest
     steps:

src/main/java/io/getunleash/repository/HttpFeatureFetcher.java

@@ -75,7 +75,8 @@ private ClientFeaturesResponse getFeatureResponse(
                 try (BufferedReader reader =
                         new BufferedReader(
                                 new InputStreamReader(
-                                        request.getInputStream(), StandardCharsets.UTF_8))) {
+                                        (InputStream) request.getContent(),
+                                        StandardCharsets.UTF_8))) {
                     String clientFeatures = reader.lines().collect(Collectors.joining("\n"));
 
                     return ClientFeaturesResponse.updated(clientFeatures);

src/test/java/io/getunleash/repository/GraalVmHttpFeatureFetcherSmoke.java

@@ -0,0 +1,78 @@
+package io.getunleash.repository;
+
+import io.getunleash.event.ClientFeaturesResponse;
+import io.getunleash.util.UnleashConfig;
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.FutureTask;
+
+public class GraalVmHttpFeatureFetcherSmoke {
+    private static final String FEATURE_NAME = "graalvm-smoke-test";
+    private static final String RESPONSE_BODY =
+            "{\"version\":1,\"features\":[{\"name\":\""
+                    + FEATURE_NAME
+                    + "\",\"enabled\":true,\"strategies\":[{\"name\":\"default\"}]}]}";
+
+    public static void main(String[] args) throws Exception {
+        try (ServerSocket serverSocket = new ServerSocket(0)) {
+            FutureTask<Void> server =
+                    new FutureTask<>(
+                            () -> {
+                                serveOneRequest(serverSocket);
+                                return null;
+                            });
+            new Thread(server, "graalvm-smoke-http").start();
+
+            UnleashConfig config =
+                    UnleashConfig.builder()
+                            .appName("graalvm-native-image-smoke-test")
+                            .unleashAPI(
+                                    new URI(
+                                            "http://127.0.0.1:"
+                                                    + serverSocket.getLocalPort()
+                                                    + "/api/"))
+                            .build();
+
+            ClientFeaturesResponse response = new HttpFeatureFetcher(config).fetchFeatures();
+            boolean found =
+                    response.getFeatures().stream()
+                            .anyMatch(feature -> FEATURE_NAME.equals(feature.getName()));
+            if (response.getStatus() != ClientFeaturesResponse.Status.CHANGED || !found) {
+                throw new IllegalStateException("Native image smoke test did not fetch features");
+            }
+
+            server.get();
+        }
+    }
+
+    private static void serveOneRequest(ServerSocket serverSocket) throws Exception {
+        try (Socket socket = serverSocket.accept();
+                BufferedReader reader =
+                        new BufferedReader(
+                                new InputStreamReader(
+                                        socket.getInputStream(), StandardCharsets.US_ASCII));
+                OutputStream output = socket.getOutputStream()) {
+            String line;
+            while ((line = reader.readLine()) != null && !line.isEmpty()) {
+                // Drain request headers before writing the response.
+            }
+
+            byte[] body = RESPONSE_BODY.getBytes(StandardCharsets.UTF_8);
+            output.write(
+                    ("HTTP/1.1 200 OK\r\n"
+                                    + "Content-Type: application/json\r\n"
+                                    + "Content-Length: "
+                                    + body.length
+                                    + "\r\n"
+                                    + "Connection: close\r\n\r\n")
+                            .getBytes(StandardCharsets.US_ASCII));
+            output.write(body);
+            output.flush();
+        }
+    }
+}