Attempt to autowire GraphQL clients in test mode

docs/src/main/asciidoc/smallrye-graphql-client.adoc

@@ -229,6 +229,11 @@ or move this over to the configuration file, `application.properties`:
 quarkus.smallrye-graphql-client.star-wars-typesafe.url=https://swapi-graphql.netlify.app/.netlify/functions/index
 ----
 
+NOTE: During *tests only*, the URL is an optional property, and if it's not specified, Quarkus will assume
+that the target of the client is the application that is being tested (typically, `http://localhost:8081/graphql`).
+This is useful if your application contains a GraphQL server-side API as well as a GraphQL client that is used for
+testing the API.
+
 `star-wars-typesafe` is the name of the configured client instance, and corresponds to the `configKey`
 in the `@GraphQLClientApi` annotation. If you don't want to specify a custom name, you can leave
 out the `configKey`, and then refer to it by using the fully qualified name of the interface.

extensions/smallrye-graphql-client/deployment/src/main/java/io/quarkus/smallrye/graphql/client/deployment/SmallRyeGraphQLClientProcessor.java

@@ -140,17 +140,29 @@ void setTypesafeApiClasses(BeanArchiveIndexBuildItem index,
      */
     @BuildStep
     @Record(RUNTIME_INIT)
-    void shortNamesToQualifiedNames(BuildProducer<SyntheticBeanBuildItem> syntheticBeans,
+    void initializeClientSupport(BuildProducer<SyntheticBeanBuildItem> syntheticBeans,
             SmallRyeGraphQLClientRecorder recorder,
             GraphQLClientsConfig quarkusConfig,
             BeanArchiveIndexBuildItem index) {
+        // to store config keys of all clients found in the application code
+        List<String> knownConfigKeys = new ArrayList<>();
+
         Map<String, String> shortNamesToQualifiedNames = new HashMap<>();
         for (AnnotationInstance annotation : index.getIndex().getAnnotations(GRAPHQL_CLIENT_API)) {
             ClassInfo clazz = annotation.target().asClass();
             shortNamesToQualifiedNames.put(clazz.name().withoutPackagePrefix(), clazz.name().toString());
+            knownConfigKeys.add(clazz.name().toString());
+        }
+
+        for (AnnotationInstance annotation : index.getIndex().getAnnotations(GRAPHQL_CLIENT)) {
+            String configKey = annotation.value().asString();
+            if (configKey == null) {
+                configKey = "default";
+            }
+            knownConfigKeys.add(configKey);
         }
 
-        RuntimeValue<GraphQLClientSupport> support = recorder.clientSupport(shortNamesToQualifiedNames);
+        RuntimeValue<GraphQLClientSupport> support = recorder.clientSupport(shortNamesToQualifiedNames, knownConfigKeys);
 
         DotName supportClassName = DotName.createSimple(GraphQLClientSupport.class.getName());
         SyntheticBeanBuildItem bean = SyntheticBeanBuildItem

extensions/smallrye-graphql-client/runtime/src/main/java/io/quarkus/smallrye/graphql/client/runtime/GraphQLClientConfigurationMergerBean.java

@@ -7,6 +7,11 @@
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
+import org.eclipse.microprofile.config.Config;
+import org.eclipse.microprofile.config.ConfigProvider;
+import org.jboss.logging.Logger;
+
+import io.quarkus.runtime.LaunchMode;
 import io.smallrye.graphql.client.impl.GraphQLClientConfiguration;
 import io.smallrye.graphql.client.impl.GraphQLClientsConfiguration;
 
@@ -21,6 +26,8 @@
 @Singleton
 public class GraphQLClientConfigurationMergerBean {
 
+    private final Logger logger = Logger.getLogger(GraphQLClientConfigurationMergerBean.class);
+
     GraphQLClientsConfiguration upstreamConfigs;
 
     @Inject
@@ -54,6 +61,32 @@ void enhanceGraphQLConfiguration() {
             }
         }
 
+        // allow automatically wiring client to the local server instance in test mode
+        if (LaunchMode.current() == LaunchMode.TEST) {
+            String testUrl = null;
+            for (String configKey : support.getKnownConfigKeys()) {
+                GraphQLClientConfiguration config = upstreamConfigs.getClient(configKey);
+                if (config.getUrl() == null) {
+                    if (testUrl == null) {
+                        testUrl = getTestingServerUrl();
+                    }
+                    logger.info("Automatically wiring the URL of GraphQL client named " + configKey + " to " + testUrl
+                            + ". If this is incorrect, " +
+                            "please set it manually using the quarkus.smallrye-graphql-client." + maybeWithQuotes(configKey)
+                            + ".url property. Also note that" +
+                            " this autowiring is only supported during tests.");
+                    config.setUrl(testUrl);
+                }
+            }
+        }
+    }
+
+    private String maybeWithQuotes(String key) {
+        if (key.contains(".")) {
+            return "\"" + key + "\"";
+        } else {
+            return key;
+        }
     }
 
     // translates a Quarkus `GraphQLClientConfig` configuration object to `GraphQLClientConfiguration` which is understood
@@ -80,6 +113,13 @@ private GraphQLClientConfiguration toSmallRyeNativeConfiguration(GraphQLClientCo
         return transformed;
     }
 
+    private String getTestingServerUrl() {
+        Config config = ConfigProvider.getConfig();
+        // the client extension doesn't have dependencies on neither the server extension nor quarkus-vertx-http, so guessing
+        // is somewhat limited
+        return "http://localhost:" + config.getOptionalValue("quarkus.http.test-port", int.class).orElse(8081) + "/graphql";
+    }
+
     public void nothing() {
     }
 }

extensions/smallrye-graphql-client/runtime/src/main/java/io/quarkus/smallrye/graphql/client/runtime/GraphQLClientSupport.java

@@ -1,5 +1,6 @@
 package io.quarkus.smallrye.graphql.client.runtime;
 
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -14,11 +15,26 @@ public class GraphQLClientSupport {
      */
     private Map<String, String> shortNamesToQualifiedNamesMapping;
 
+    /**
+     * All config keys of clients found in the application. The reason for having this is that in TEST mode,
+     * if a config key is used but doesn't have any associated configuration, we can automatically generate a configuration
+     * containing a guess of the target URL.
+     */
+    private List<String> knownConfigKeys;
+
     public Map<String, String> getShortNamesToQualifiedNamesMapping() {
         return shortNamesToQualifiedNamesMapping;
     }
 
     public void setShortNamesToQualifiedNamesMapping(Map<String, String> shortNamesToQualifiedNamesMapping) {
         this.shortNamesToQualifiedNamesMapping = shortNamesToQualifiedNamesMapping;
     }
+
+    public void setKnownConfigKeys(List<String> knownConfigKeys) {
+        this.knownConfigKeys = knownConfigKeys;
+    }
+
+    public List<String> getKnownConfigKeys() {
+        return knownConfigKeys;
+    }
 }

extensions/smallrye-graphql-client/runtime/src/main/java/io/quarkus/smallrye/graphql/client/runtime/SmallRyeGraphQLClientRecorder.java

@@ -34,9 +34,11 @@ public void setTypesafeApiClasses(List<String> apiClassNames) {
         configBean.addTypesafeClientApis(classes);
     }
 
-    public RuntimeValue<GraphQLClientSupport> clientSupport(Map<String, String> shortNamesToQualifiedNames) {
+    public RuntimeValue<GraphQLClientSupport> clientSupport(Map<String, String> shortNamesToQualifiedNames,
+            List<String> knownConfigKeys) {
         GraphQLClientSupport support = new GraphQLClientSupport();
         support.setShortNamesToQualifiedNamesMapping(shortNamesToQualifiedNames);
+        support.setKnownConfigKeys(knownConfigKeys);
         return new RuntimeValue<>(support);
     }