Detect Federation automatically by the Maven plugin

.gitignore

@@ -74,6 +74,7 @@ client/shade/dependency-reduced-pom.xml
 # testing artifacts
 /tools/maven-plugin-tests/testing-project/log.txt
 /tools/maven-plugin-tests/testing-project-multi-module/log.txt
+/tools/maven-plugin-tests/testing-project-federation/log.txt
 
 # mkdocs output
 site

common/schema-builder/src/main/java/io/smallrye/graphql/schema/ScanningContext.java

@@ -1,6 +1,7 @@
 package io.smallrye.graphql.schema;
 
 import org.jboss.jandex.IndexView;
+import org.jboss.jandex.Indexer;
 
 /**
  * A simple registry to hold the current scanning info
@@ -19,6 +20,8 @@ public static void register(IndexView index) {
 
     public static IndexView getIndex() {
         return current.get().index;
+        Indexer indexer;
+        SchemaBuilder.class.getProtectionDomain().getCodeSource().getLocation()
     }
 
     public static void remove() {

common/schema-builder/src/main/java/io/smallrye/graphql/schema/SchemaBuilder.java

@@ -188,7 +188,6 @@ private void addDirectiveTypes(Schema schema) {
         }
         // bean validation directives
         schema.addDirectiveType(BeanValidationDirectivesHelper.CONSTRAINT_DIRECTIVE_TYPE);
-
         // rolesAllowed directive
         schema.addDirectiveType(RolesAllowedDirectivesHelper.ROLES_ALLOWED_DIRECTIVE_TYPE);
     }

docs/maven-plugin.md

@@ -49,8 +49,9 @@ true, you can control what types should be included. Default is
 
 - `includeIntrospectionTypes` - Include the introspection types in the schema. Default false.
 
-- `federationEnabled` - Enable GraphQL Federation. You should generally use this
-in conjunction with `includeDirectives`. Default false.
+- `federationEnabled` - Enable GraphQL Federation. This is automatically 
+enabled if any Federation-related annotations are found in your application, otherwise the default is false.
+You should generally use this in conjunction with `includeDirectives`.
 
 - `typeAutoNameStrategy` - Strategy for transforming class names into GraphQL type names. 
 Valid values are `MergeInnerClass`, `Full` and`Default`.

tools/maven-plugin-tests/src/test/java/io/smallrye/graphql/mavenplugin/test/GenerateSchemaTest.java

@@ -23,6 +23,8 @@
 public class GenerateSchemaTest {
 
     private final Path SCHEMA_FILE_PATH = Paths.get("testing-project", "target", "generated", "schema.graphql");
+    private final Path SCHEMA_FILE_PATH_FEDERATION = Paths.get("testing-project-federation", "target", "generated",
+            "schema.graphql");
     private final Path SCHEMA_FILE_PATH_MULTI_MODULE = Paths.get("testing-project-multi-module", "api", "target", "generated",
             "schema.graphql");
 
@@ -34,7 +36,7 @@ public void before() {
 
     @Test
     public void testDefaults() throws Exception {
-        String schema = execute(Collections.emptyMap());
+        String schema = execute(Collections.emptyMap(), "testing-project", SCHEMA_FILE_PATH);
         assertThat("Directives should not be included",
                 schema, not(containsString("directive @skip")));
         assertThat("Introspection types should not be included",
@@ -47,38 +49,47 @@ public void testDefaults() throws Exception {
                 schema, not(containsString("type _Service")));
     }
 
+    @Test
+    public void testFederationDetectedAutomatically() throws Exception {
+        String schema = execute(Collections.emptyMap(), "testing-project-federation", SCHEMA_FILE_PATH_FEDERATION);
+        assertThat("Federation should be activated automatically if any related annotations are present",
+                schema, containsString("type _Service"));
+    }
+
     @Test
     public void testIncludeDirectives() throws Exception {
-        String schema = execute(Collections.singletonMap("includeDirectives", "true"));
+        String schema = execute(Collections.singletonMap("includeDirectives", "true"), "testing-project", SCHEMA_FILE_PATH);
         assertThat("Directives should be included",
                 schema, containsString("directive @skip"));
     }
 
     @Test
     public void testIncludeIntrospectionTypes() throws Exception {
-        String schema = execute(Collections.singletonMap("includeIntrospectionTypes", "true"));
+        String schema = execute(Collections.singletonMap("includeIntrospectionTypes", "true"), "testing-project",
+                SCHEMA_FILE_PATH);
         assertThat("Introspection types should be included",
                 schema, containsString("type __Schema"));
     }
 
     @Test
     public void testIncludeSchemaDefinition() throws Exception {
-        String schema = execute(Collections.singletonMap("includeSchemaDefinition", "true"));
+        String schema = execute(Collections.singletonMap("includeSchemaDefinition", "true"), "testing-project",
+                SCHEMA_FILE_PATH);
         assertThat("Schema definition should be included",
                 schema, containsString("schema {\n  query: Query"));
     }
 
     @Test
     public void testTypeAutoNameStrategy() throws Exception {
-        String schema = execute(Collections.singletonMap("typeAutoNameStrategy", "Full"));
+        String schema = execute(Collections.singletonMap("typeAutoNameStrategy", "Full"), "testing-project", SCHEMA_FILE_PATH);
         assertThat("Fully qualified class names should be used for GraphQL types",
                 schema, containsString("type org_acme_Foo"));
     }
 
     @Test
-    public void testFederationEnabled() throws Exception {
-        String schema = execute(Collections.singletonMap("federationEnabled", "true"));
-        assertThat("Federation should be enabled",
+    public void testFederationEnabledExplicitly() throws Exception {
+        String schema = execute(Collections.singletonMap("federationEnabled", "true"), "testing-project", SCHEMA_FILE_PATH);
+        assertThat("Federation should be enabled when explicitly requested, even though there are no annotations",
                 schema, containsString("type _Service"));
     }
 
@@ -102,8 +113,11 @@ public void testMultiModuleProject() throws Exception {
                 SCHEMA_FILE_PATH_MULTI_MODULE.toFile().exists());
     }
 
-    private String execute(Map<String, String> properties) throws VerificationException, IOException {
-        Verifier verifier = new Verifier(new File("testing-project").getAbsolutePath());
+    private String execute(Map<String, String> properties,
+            String pathToProject,
+            Path pathToExpectedGeneratedSchemaFile)
+            throws VerificationException, IOException {
+        Verifier verifier = new Verifier(new File(pathToProject).getAbsolutePath());
         verifier.setSystemProperty("plugin.version", System.getProperty("plugin.version"));
         properties.forEach(verifier::setSystemProperty);
 
@@ -116,8 +130,8 @@ private String execute(Map<String, String> properties) throws VerificationExcept
         verifier.verifyErrorFreeLog();
         verifier.verifyTextInLog("Wrote the schema to ");
 
-        Assert.assertTrue("File " + SCHEMA_FILE_PATH.toAbsolutePath() + " expected but not found",
-                SCHEMA_FILE_PATH.toFile().exists());
-        return String.join("\n", Files.readAllLines(SCHEMA_FILE_PATH));
+        Assert.assertTrue("File " + pathToExpectedGeneratedSchemaFile.toAbsolutePath() + " expected but not found",
+                pathToExpectedGeneratedSchemaFile.toFile().exists());
+        return String.join("\n", Files.readAllLines(pathToExpectedGeneratedSchemaFile));
     }
 }

tools/maven-plugin-tests/testing-project-federation/pom.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <name>SmallRye: GraphQL Maven plugin tests :: Mock project</name>
+    <description>Mock project for testing the Maven plugin</description>
+
+    <groupId>io.smallrye</groupId>
+    <artifactId>smallrye-graphql-maven-plugin-mock-project</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <properties>
+        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>11</maven.compiler.source>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.smallrye</groupId>
+            <artifactId>smallrye-graphql</artifactId>
+            <version>${plugin.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>io.smallrye</groupId>
+                <artifactId>smallrye-graphql-maven-plugin</artifactId>
+                <configuration>
+                    <includeSchemaDefinition>${includeSchemaDefinition}</includeSchemaDefinition>
+                    <includeDirectives>${includeDirectives}</includeDirectives>
+                    <includeIntrospectionTypes>${includeIntrospectionTypes}</includeIntrospectionTypes>
+                    <typeAutoNameStrategy>${typeAutoNameStrategy}</typeAutoNameStrategy>
+                    <includeScalars>${includeScalars}</includeScalars>
+                </configuration>
+                <version>${plugin.version}</version>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

tools/maven-plugin-tests/testing-project-federation/src/main/java/org/acme/Foo.java

@@ -0,0 +1,17 @@
+package org.acme;
+
+import io.smallrye.graphql.api.federation.Key;
+
+@Key(fields = "id")
+public class Foo {
+
+    private Integer number;
+
+    public Integer getNumber() {
+        return number;
+    }
+
+    public void setNumber(Integer number) {
+        this.number = number;
+    }
+}

tools/maven-plugin-tests/testing-project-federation/src/main/java/org/acme/TestingApi.java

@@ -0,0 +1,18 @@
+package org.acme;
+
+import org.eclipse.microprofile.graphql.GraphQLApi;
+import org.eclipse.microprofile.graphql.Query;
+
+import java.util.Collections;
+import java.util.List;
+
+@GraphQLApi
+class TestingApi {
+
+    @Query
+    public Foo getFoo() {
+        return null;
+    }
+
+
+}

tools/maven-plugin/src/main/java/io/smallrye/graphql/mavenplugin/GenerateSchemaMojo.java

@@ -25,6 +25,7 @@
 import org.apache.maven.plugins.annotations.ResolutionScope;
 import org.apache.maven.project.MavenProject;
 import org.eclipse.microprofile.graphql.Name;
+import org.jboss.jandex.ClassInfo;
 import org.jboss.jandex.CompositeIndex;
 import org.jboss.jandex.Index;
 import org.jboss.jandex.IndexView;
@@ -133,13 +134,26 @@ public void execute() throws MojoExecutionException {
             ClassLoader classLoader = getClassLoader();
             Thread.currentThread().setContextClassLoader(classLoader);
 
-            if (mavenConfig.isFederationEnabled()) {
+            IndexView index = createIndex();
+            boolean foundAnyFederationAnnotation = false;
+            for (ClassInfo federationAnnotationType : index.getClassesInPackage("io.smallrye.graphql.api.federation")) {
+                if (federationAnnotationType.isAnnotation()) {
+                    if (!index.getAnnotations(federationAnnotationType.name()).isEmpty()) {
+                        foundAnyFederationAnnotation = true;
+                        break;
+                    }
+                }
+            }
+            boolean enableFederation = false;
+            if (mavenConfig.isFederationEnabled()
+                    || foundAnyFederationAnnotation
+                    || Boolean.getBoolean("smallrye.graphql.federation.enabled")) {
                 // to make sure the schema builder knows that federation is enabled
                 System.setProperty("smallrye.graphql.federation.enabled", "true");
+                enableFederation = true;
             }
 
-            IndexView index = createIndex();
-            String schema = generateSchema(index);
+            String schema = generateSchema(index, enableFederation);
             if (schema != null) {
                 write(schema);
             } else {
@@ -235,10 +249,10 @@ private Index indexModuleClasses(File classesDir) throws IOException {
         return indexer.complete();
     }
 
-    private String generateSchema(IndexView index) {
+    private String generateSchema(IndexView index, boolean enableFederation) {
         Schema internalSchema = SchemaBuilder.build(index, mavenConfig.typeAutoNameStrategy);
         GraphQLSchema graphQLSchema = Bootstrap.bootstrap(internalSchema, true);
-        if (graphQLSchema != null && mavenConfig.isFederationEnabled()) {
+        if (graphQLSchema != null && enableFederation) {
             graphQLSchema = Federation.transform(graphQLSchema)
                     .fetchEntities(new FederationDataFetcher(graphQLSchema.getQueryType(), graphQLSchema.getCodeRegistry()))
                     .resolveEntityType(fetchEntityType())