From 272f4d0512d984d44a133c1746cd97880a40f896 Mon Sep 17 00:00:00 2001
From: Santiago Pericas-Geertsen <santiago.pericasgeertsen@oracle.com>
Date: Fri, 16 Aug 2024 10:22:49 -0400
Subject: [PATCH] Implements support for client gRPC channel injections. Does
 not use CDI qualifiers for forward compatibility with our declarative API
 (annotations will be reused). New test that shows field and constructor
 injection.

---
 .../main/java/io/helidon/grpc/api/Grpc.java   |  4 +-
 .../grpc/client/ChannelProducer.java          | 13 +----
 .../grpc/client/ChannelInjectionTest.java     | 50 +++++++++++++++++++
 3 files changed, 53 insertions(+), 14 deletions(-)
 create mode 100644 microprofile/grpc/client/src/test/java/io/helidon/microprofile/grpc/client/ChannelInjectionTest.java

diff --git a/grpc/api/src/main/java/io/helidon/grpc/api/Grpc.java b/grpc/api/src/main/java/io/helidon/grpc/api/Grpc.java
index 4f5a50c2e70..3a4f3585cfe 100644
--- a/grpc/api/src/main/java/io/helidon/grpc/api/Grpc.java
+++ b/grpc/api/src/main/java/io/helidon/grpc/api/Grpc.java
@@ -275,7 +275,7 @@ public interface Grpc {
     }
 
     /**
-     * An annotation to indicate the response type of a gRPC method.
+     * An annotation to indicate the response type of gRPC method.
      */
     @Target(ElementType.METHOD)
     @Retention(RetentionPolicy.RUNTIME)
@@ -293,7 +293,7 @@ public interface Grpc {
     /**
      * An annotation that can be used to specify the name of a configured gRPC channel.
      */
-    @Target({ElementType.TYPE, ElementType.METHOD})
+    @Target({ElementType.TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.PARAMETER})
     @Retention(RetentionPolicy.RUNTIME)
     @interface GrpcChannel {
 
diff --git a/microprofile/grpc/client/src/main/java/io/helidon/microprofile/grpc/client/ChannelProducer.java b/microprofile/grpc/client/src/main/java/io/helidon/microprofile/grpc/client/ChannelProducer.java
index 9a1cb1f3c5f..521965b2ed8 100644
--- a/microprofile/grpc/client/src/main/java/io/helidon/microprofile/grpc/client/ChannelProducer.java
+++ b/microprofile/grpc/client/src/main/java/io/helidon/microprofile/grpc/client/ChannelProducer.java
@@ -57,9 +57,8 @@ public class ChannelProducer {
      * @return a gRPC {@link io.grpc.Channel}
      */
     @Produces
-    @Grpc.GrpcChannel(GrpcChannelsProvider.DEFAULT_CHANNEL_NAME)
     public Channel get(InjectionPoint injectionPoint) {
-        Grpc.GrpcChannel qualifier = injectionPoint.getQualifiers()
+        Grpc.GrpcChannel qualifier = injectionPoint.getAnnotated().getAnnotations()
                 .stream()
                 .filter(q -> q.annotationType().equals(Grpc.GrpcChannel.class))
                 .map(q -> (Grpc.GrpcChannel) q)
@@ -70,16 +69,6 @@ public Channel get(InjectionPoint injectionPoint) {
         return findChannel(name);
     }
 
-    /**
-     * Produces the default gRPC {@link io.grpc.Channel}.
-     *
-     * @return the default gRPC {@link io.grpc.Channel}
-     */
-    @Produces
-    public Channel getDefaultChannel() {
-        return findChannel(GrpcChannelsProvider.DEFAULT_CHANNEL_NAME);
-    }
-
     /**
      * Obtain the named {@link io.grpc.Channel}.
      *
diff --git a/microprofile/grpc/client/src/test/java/io/helidon/microprofile/grpc/client/ChannelInjectionTest.java b/microprofile/grpc/client/src/test/java/io/helidon/microprofile/grpc/client/ChannelInjectionTest.java
new file mode 100644
index 00000000000..3a427d2f42d
--- /dev/null
+++ b/microprofile/grpc/client/src/test/java/io/helidon/microprofile/grpc/client/ChannelInjectionTest.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.helidon.microprofile.grpc.client;
+
+import io.helidon.grpc.api.Grpc;
+import io.helidon.microprofile.testing.junit5.HelidonTest;
+
+import io.grpc.Channel;
+import jakarta.inject.Inject;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@HelidonTest
+class ChannelInjectionTest {
+
+    @Inject
+    @Grpc.GrpcChannel("echo-channel")
+    private Channel echoChannel1;
+
+    private final Channel echoChannel2;
+
+    @Inject
+    ChannelInjectionTest(@Grpc.GrpcChannel("echo-channel") Channel echoChannel2) {
+        this.echoChannel2 = echoChannel2;
+    }
+
+    @Test
+    void testInjection() {
+        assertThat(echoChannel1, notNullValue());
+        assertThat(echoChannel2, notNullValue());
+        assertEquals(echoChannel1.getClass(), echoChannel2.getClass());
+        assertEquals(echoChannel1.authority(), echoChannel2.authority());
+    }
+}