Support HttpEngine openConnection.

Use the JavaCronetProvider from cronet-fallback.
Implement just enough to support URLConnection.

gradle/libs.versions.toml

@@ -1,4 +1,5 @@
 [versions]
+cronet-fallback = "119.6045.31"
 robolectric-nativeruntime-dist-compat = "1.0.9"
 
 # https://developer.android.com/studio/releases
@@ -128,6 +129,7 @@ play-services-basement = "18.0.1"
 
 [libraries]
 android-gradle = { module = "com.android.tools.build:gradle", version.ref = "android-gradle" }
+cronet-fallback = { module = "org.chromium.net:cronet-fallback", version.ref = "cronet-fallback" }
 kotlin-gradle = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
 spotless-gradle = { module = "com.diffplug.spotless:spotless-plugin-gradle", version.ref = "spotless-gradle" }
 detekt-gradle = { module = "io.gitlab.arturbosch.detekt:detekt-gradle-plugin", version.ref = "detekt-gradle" }

integration_tests/ctesque/src/main/AndroidManifest.xml

@@ -3,6 +3,9 @@
   Manifest for ctesque tests
 -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+  <!-- Required for HttpEngineTest -->
+  <uses-permission android:name="android.permission.INTERNET" />
+  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 
   <application />
 </manifest>

integration_tests/ctesque/src/sharedTest/java/android/net/http/HttpEngineTest.java

@@ -0,0 +1,32 @@
+package android.net.http;
+
+import android.content.Context;
+import android.os.Build;
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SdkSuppress;
+import java.net.URL;
+import java.net.URLConnection;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+import org.robolectric.annotation.internal.DoNotInstrument;
+
+@DoNotInstrument
+@RunWith(AndroidJUnit4.class)
+@Config(minSdk = Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+@SdkSuppress(minSdkVersion = Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+public class HttpEngineTest {
+  @Test
+  public void shouldSupportHttpClient() throws Exception {
+    Context context = ApplicationProvider.getApplicationContext();
+
+    HttpEngine engine = new HttpEngine.Builder(context).build();
+
+    URLConnection con = engine.openConnection(new URL("https://google.com/robots.txt"));
+
+    // Check how to test network in robolectric builds
+    //    String response = new String(con.getInputStream().readAllBytes());
+    //    assertThat(response).contains("Disallow");
+  }
+}

shadows/framework/build.gradle

@@ -57,6 +57,8 @@ dependencies {
 
     api "androidx.test:monitor:$axtMonitorVersion@aar"
 
+    implementation(libs.cronet.fallback)
+
     implementation libs.error.prone.annotations
     compileOnly libs.findbugs.jsr305
     api libs.sqlite4java

shadows/framework/src/main/java/org/robolectric/shadows/ShadowHttpEngine.java

@@ -0,0 +1,194 @@
+package org.robolectric.shadows;
+
+import android.annotation.NonNull;
+import android.content.Context;
+import android.net.Network;
+import android.net.http.ExperimentalBidirectionalStream;
+import android.net.http.ExperimentalHttpEngine;
+import android.net.http.ExperimentalUrlRequest;
+import android.net.http.HttpEngine;
+import android.net.http.IHttpEngineBuilder;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLStreamHandlerFactory;
+import java.time.Instant;
+import java.util.Collections;
+import java.util.Date;
+import java.util.Set;
+import java.util.concurrent.Executor;
+import org.chromium.net.ExperimentalCronetEngine;
+import org.chromium.net.impl.JavaCronetProvider;
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+import org.robolectric.versioning.AndroidVersions.U;
+
+@SuppressWarnings({"NewApi", "deprecation"})
+@Implements(value = HttpEngine.Builder.class, minSdk = U.SDK_INT)
+public class ShadowHttpEngine {
+
+  @Implementation
+  protected static IHttpEngineBuilder createBuilderDelegate(Context context)
+      throws ClassNotFoundException {
+    return new CronetEngineBuilderWrapper(context);
+  }
+
+  static class CronetEngineBuilderWrapper extends IHttpEngineBuilder {
+    private final ExperimentalCronetEngine.Builder backend;
+
+    public CronetEngineBuilderWrapper(Context context) {
+      this.backend =
+          (ExperimentalCronetEngine.Builder) new JavaCronetProvider(context).createBuilder();
+    }
+
+    @Override
+    public String getDefaultUserAgent() {
+      return backend.getDefaultUserAgent();
+    }
+
+    @Override
+    public IHttpEngineBuilder setUserAgent(String userAgent) {
+      backend.setUserAgent(userAgent);
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder setStoragePath(String value) {
+      backend.setStoragePath(value);
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder addQuicHint(String host, int port, int alternatePort) {
+      backend.addQuicHint(host, port, alternatePort);
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder addPublicKeyPins(
+        String hostName,
+        Set<byte[]> pinsSha256,
+        boolean includeSubdomains,
+        Instant expirationInstant) {
+      backend.addPublicKeyPins(
+          hostName, pinsSha256, includeSubdomains, Date.from(expirationInstant));
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder setQuicOptions(@NonNull android.net.http.QuicOptions options) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder setDnsOptions(@NonNull android.net.http.DnsOptions options) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder setConnectionMigrationOptions(
+        @NonNull android.net.http.ConnectionMigrationOptions options) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder enableBrotli(boolean value) {
+      return this;
+    }
+
+    @Override
+    protected Set<Integer> getSupportedConfigOptions() {
+      return Collections.emptySet();
+    }
+
+    @Override
+    public IHttpEngineBuilder enableNetworkQualityEstimator(boolean value) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder setThreadPriority(int priority) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder enableHttp2(boolean b) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder enableHttpCache(int i, long l) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder enablePublicKeyPinningBypassForLocalTrustAnchors(boolean b) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder enableQuic(boolean b) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder enableSdch(boolean b) {
+      return this;
+    }
+
+    @Override
+    public IHttpEngineBuilder setExperimentalOptions(String s) {
+      return this;
+    }
+
+    public ExperimentalHttpEngine build() {
+      return new CronetEngineWrapper(backend.build());
+    }
+  }
+
+  static class CronetEngineWrapper extends ExperimentalHttpEngine {
+
+    private final ExperimentalCronetEngine backend;
+
+    public CronetEngineWrapper(ExperimentalCronetEngine backend) {
+      this.backend = backend;
+    }
+
+    @Override
+    public void shutdown() {
+      backend.shutdown();
+    }
+
+    @Override
+    public URLConnection openConnection(URL url) throws IOException {
+      return backend.openConnection(url);
+    }
+
+    @Override
+    public URLStreamHandlerFactory createUrlStreamHandlerFactory() {
+      return backend.createURLStreamHandlerFactory();
+    }
+
+    @Override
+    public void bindToNetwork(Network network) {
+      long networkHandle = backend.UNBIND_NETWORK_HANDLE;
+      if (network != null) {
+        networkHandle = network.getNetworkHandle();
+      }
+      backend.bindToNetwork(networkHandle);
+    }
+
+    @Override
+    public ExperimentalBidirectionalStream.Builder newBidirectionalStreamBuilder(
+        String url, Executor executor, android.net.http.BidirectionalStream.Callback callback) {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ExperimentalUrlRequest.Builder newUrlRequestBuilder(
+        String url, Executor executor, android.net.http.UrlRequest.Callback callback) {
+      // TODO
+      throw new UnsupportedOperationException();
+    }
+  }
+}