Unzip/Deflate content on error status for Default Client (#2184)

* Unzip/Deflate content on error status for Default Client

* Fix assert message

---------

Co-authored-by: Marvin Froeder <velo@users.noreply.github.com>

core/src/main/java/feign/Client.java

@@ -132,13 +132,12 @@ public interface Client {
       if (status >= 400) {
         stream = connection.getErrorStream();
       } else {
-        if (this.isGzip(headers.get(CONTENT_ENCODING))) {
-          stream = new GZIPInputStream(connection.getInputStream());
-        } else if (this.isDeflate(headers.get(CONTENT_ENCODING))) {
-          stream = new InflaterInputStream(connection.getInputStream());
-        } else {
-          stream = connection.getInputStream();
-        }
+        stream = connection.getInputStream();
+      }
+      if (this.isGzip(headers.get(CONTENT_ENCODING))) {
+        stream = new GZIPInputStream(stream);
+      } else if (this.isDeflate(headers.get(CONTENT_ENCODING))) {
+        stream = new InflaterInputStream(stream);
       }
       return Response.builder()
           .status(status)

core/src/test/java/feign/client/AbstractClientTest.java

@@ -17,6 +17,7 @@ import static feign.Util.UTF_8;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.entry;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
 import feign.Client;
 import feign.CollectionFormat;
 import feign.Feign.Builder;
@@ -31,6 +32,7 @@ import feign.assertj.MockWebServerAssertions;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Collections;
@@ -410,6 +412,32 @@ public abstract class AbstractClientTest {
         .isEqualToIgnoringCase(responseData);
   }
 
+  @Test
+  public void canSupportGzipOnError() throws Exception {
+    /* enqueue a zipped response */
+    final String responseData = "Compressed Data";
+    server.enqueue(new MockResponse()
+        .setResponseCode(400)
+        .addHeader("Content-Encoding", "gzip")
+        .setBody(new Buffer().write(compress(responseData))));
+
+    TestInterface api = newBuilder()
+        .target(TestInterface.class, "http://localhost:" + server.getPort());
+
+    try {
+      api.get();
+      fail("Expect FeignException");
+    } catch (FeignException e) {
+      /* verify that the response is unzipped */
+      assertThat(e.responseBody())
+          .isNotEmpty()
+          .map(body -> new String(body.array(), StandardCharsets.UTF_8))
+          .get()
+          .isEqualTo(responseData);
+    }
+
+  }
+
   @Test
   public void canSupportDeflate() throws Exception {
     /* enqueue a zipped response */
@@ -428,6 +456,31 @@ public abstract class AbstractClientTest {
         .isEqualToIgnoringCase(responseData);
   }
 
+  @Test
+  public void canSupportDeflateOnError() throws Exception {
+    /* enqueue a zipped response */
+    final String responseData = "Compressed Data";
+    server.enqueue(new MockResponse()
+        .setResponseCode(400)
+        .addHeader("Content-Encoding", "deflate")
+        .setBody(new Buffer().write(deflate(responseData))));
+
+    TestInterface api = newBuilder()
+        .target(TestInterface.class, "http://localhost:" + server.getPort());
+
+    try {
+      api.get();
+      fail("Expect FeignException");
+    } catch (FeignException e) {
+      /* verify that the response is unzipped */
+      assertThat(e.responseBody())
+          .isNotEmpty()
+          .map(body -> new String(body.array(), StandardCharsets.UTF_8))
+          .get()
+          .isEqualTo(responseData);
+    }
+  }
+
   @Test
   public void canExceptCaseInsensitiveHeader() throws Exception {
     /* enqueue a zipped response */

googlehttpclient/src/test/java/feign/googlehttpclient/GoogleHttpClientTest.java

@@ -54,11 +54,21 @@ public class GoogleHttpClientTest extends AbstractClientTest {
     assumeFalse("Google HTTP client client do not support gzip compression", false);
   }
 
+  @Override
+  public void canSupportGzipOnError() throws Exception {
+    assumeFalse("Google HTTP client client do not support gzip compression", false);
+  }
+
   @Override
   public void canSupportDeflate() throws Exception {
     assumeFalse("Google HTTP client client do not support deflate compression", false);
   }
 
+  @Override
+  public void canSupportDeflateOnError() throws Exception {
+    assumeFalse("Google HTTP client client do not support deflate compression", false);
+  }
+
   @Override
   public void canExceptCaseInsensitiveHeader() throws Exception {
     assumeFalse("Google HTTP client client do not support gzip compression", false);

jaxrs2/src/test/java/feign/jaxrs2/JAXRSClientTest.java

@@ -152,11 +152,21 @@ public class JAXRSClientTest extends AbstractClientTest {
     assumeFalse("JaxRS client do not support gzip compression", false);
   }
 
+  @Override
+  public void canSupportGzipOnError() throws Exception {
+    assumeFalse("JaxRS client do not support gzip compression", false);
+  }
+
   @Override
   public void canSupportDeflate() throws Exception {
     assumeFalse("JaxRS client do not support deflate compression", false);
   }
 
+  @Override
+  public void canSupportDeflateOnError() throws Exception {
+    assumeFalse("JaxRS client do not support deflate compression", false);
+  }
+
   @Override
   public void canExceptCaseInsensitiveHeader() throws Exception {
     assumeFalse("JaxRS client do not support gzip compression", false);

okhttp/src/test/java/feign/okhttp/OkHttpClientTest.java

@@ -115,11 +115,21 @@ public class OkHttpClientTest extends AbstractClientTest {
     assumeFalse("OkHTTP client do not support gzip compression", false);
   }
 
+  @Override
+  public void canSupportGzipOnError() throws Exception {
+    assumeFalse("OkHTTP client do not support gzip compression", false);
+  }
+
   @Override
   public void canSupportDeflate() throws Exception {
     assumeFalse("OkHTTP client do not support deflate compression", false);
   }
 
+  @Override
+  public void canSupportDeflateOnError() throws Exception {
+    assumeFalse("OkHTTP client do not support deflate compression", false);
+  }
+
   @Override
   public void canExceptCaseInsensitiveHeader() throws Exception {
     assumeFalse("OkHTTP client do not support gzip compression", false);