Add automatic integration configuration

This adds a configuration step for integrations, allowing them to use
`smithy-build.json` settings that aren't used by the generator that
they target.

Generators using the node mapper helper for their settings will have
this set for free. Others will need to grab it themselves.

smithy-codegen-core/src/main/java/software/amazon/smithy/codegen/core/SmithyIntegration.java

@@ -19,6 +19,7 @@
 import java.util.List;
 import software.amazon.smithy.build.FileManifest;
 import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.node.ObjectNode;
 import software.amazon.smithy.utils.AbstractCodeWriter;
 import software.amazon.smithy.utils.CodeInterceptor;
 import software.amazon.smithy.utils.CodeSection;
@@ -70,6 +71,50 @@ default byte priority() {
         return 0;
     }
 
+    /**
+     * Configures the integration.
+     *
+     * <p>This provides access to both the parsed settings for the generator and
+     * an unparsed {@link ObjectNode} containing settings for all integrations.
+     * Integrations SHOULD put all of their settings inside a nested object so
+     * that they don't experience conflicts with other integrations.
+     *
+     * <p>The following {@code smithy-build.json} file contains an example of how
+     * this configuration will be set.
+     *
+     * <pre>{@code
+     * {
+     *     "version": "1.0",
+     *     "projections": {
+     *         "codegen-projection": {
+     *             "plugins": {
+     *                 "code-generator": {
+     *                     "service": "com.example#DocumentedService",
+     *                     "integrations": {
+     *                         "my-integration": {
+     *                             "example-setting": "foo"
+     *                         }
+     *                     }
+     *                 }
+     *             }
+     *         }
+     *     }
+     * }
+     * }</pre>
+     *
+     * <p>In this example, everything under the key {@code integrations} will be
+     * provided as the {@code rawSettings} value and the {@code my-integration} key
+     * represents the settings for a particular integration.
+     *
+     * <p>Integrations SHOULD use modeled traits as much as possible to drive
+     * configuration. This is intended for configuration that doesn't make sense
+     * as a trait, such as configuring a documentation theme.
+     *
+     * @param settings Settings used to generate code.
+     * @param integrationSettings Settings used to configure integrations.
+     */
+    default void configure(S settings, ObjectNode integrationSettings) {}
+
     /**
      * Gets the names of integrations that this integration must come before.
      *
@@ -103,7 +148,7 @@ default List<String> runAfter() {
      * <p>By default, this method will return the given {@code model} as-is.
      *
      * @param model Model being generated.
-     * @param settings Setting used to generate code.
+     * @param settings Settings used to generate code.
      * @return Returns the updated model.
      */
     default Model preprocessModel(Model model, S settings) {
@@ -122,7 +167,7 @@ default Model preprocessModel(Model model, S settings) {
      * <p>This integration method should be called only after {@link #preprocessModel}.
      *
      * @param model Model being generated.
-     * @param settings Setting used to generate.
+     * @param settings Settings used to generate.
      * @param symbolProvider The original {@code SymbolProvider}.
      * @return The decorated {@code SymbolProvider}.
      */

smithy-codegen-core/src/main/java/software/amazon/smithy/codegen/core/directed/CodegenDirector.java

@@ -36,6 +36,7 @@
 import software.amazon.smithy.model.neighbor.Walker;
 import software.amazon.smithy.model.node.Node;
 import software.amazon.smithy.model.node.NodeMapper;
+import software.amazon.smithy.model.node.ObjectNode;
 import software.amazon.smithy.model.shapes.EnumShape;
 import software.amazon.smithy.model.shapes.IntEnumShape;
 import software.amazon.smithy.model.shapes.OperationShape;
@@ -74,6 +75,7 @@ public final class CodegenDirector<
     private ShapeId service;
     private Model model;
     private S settings;
+    private ObjectNode integrationSettings = Node.objectNode();
     private FileManifest fileManifest;
     private Supplier<Iterable<I>> integrationFinder;
     private DirectedCodegen<C, S, I> directedCodegen;
@@ -159,6 +161,9 @@ public void settings(S settings) {
      * You will need to manually deserialize your settings if using types that
      * are not supported by Smithy's {@link NodeMapper}.
      *
+     * <p>This will also set {@link #integrationSettings} if the {@code integrations}
+     * key is present.
+     *
      * @param settingsType Settings type to deserialize into.
      * @param settingsNode Settings node value to deserialize.
      * @return Returns the deserialized settings as this is needed to provide a service shape ID.
@@ -167,9 +172,47 @@ public S settings(Class<S> settingsType, Node settingsNode) {
         LOGGER.fine(() -> "Loading codegen settings from node value: " + settingsNode.getSourceLocation());
         S deserialized = new NodeMapper().deserialize(settingsNode, settingsType);
         settings(deserialized);
+        settingsNode.asObjectNode()
+            .flatMap(node -> node.getObjectMember("integrations"))
+            .ifPresent(this::integrationSettings);
         return deserialized;
     }
 
+    /**
+     * Sets the settings node to be passed to integrations.
+     *
+     * <p>Generators MUST set this with the {@code integrations} key from their
+     * plugin settings.
+     *
+     * <pre>{@code
+     * {
+     *     "version": "1.0",
+     *     "projections": {
+     *         "codegen-projection": {
+     *             "plugins": {
+     *                 "code-generator": {
+     *                     "service": "com.example#DocumentedService",
+     *                     "integrations": {
+     *                         "my-integration": {
+     *                             "example-setting": "foo"
+     *                         }
+     *                     }
+     *                 }
+     *             }
+     *         }
+     *     }
+     * }
+     * }</pre>
+     *
+     * <p>In this example, the value of the {@code integrations} key is what must
+     * be passed to this method.
+     *
+     * @param integrationSettings Settings used to configure integrations.
+     */
+    public void integrationSettings(ObjectNode integrationSettings) {
+        this.integrationSettings = Objects.requireNonNull(integrationSettings);
+    }
+
     /**
      * Sets the required file manifest used to write files to disk.
      *
@@ -366,7 +409,10 @@ private void performModelTransforms() {
     private List<I> findIntegrations() {
         LOGGER.fine(() -> "Finding integration implementations of " + integrationClass.getName());
         List<I> integrations = SmithyIntegration.sort(integrationFinder.get());
-        integrations.forEach(i -> LOGGER.finest(() -> "Found integration " + i.getClass().getCanonicalName()));
+        integrations.forEach(i -> {
+            LOGGER.finest(() -> "Found integration " + i.getClass().getCanonicalName());
+            i.configure(settings, integrationSettings);
+        });
         return integrations;
     }
 

smithy-codegen-core/src/test/java/software/amazon/smithy/codegen/core/directed/CapturingIntegration.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.codegen.core.directed;
+
+import software.amazon.smithy.model.node.Node;
+import software.amazon.smithy.model.node.ObjectNode;
+
+public class CapturingIntegration implements TestIntegration {
+    public ObjectNode integrationSettings = Node.objectNode();
+
+    @Override
+    public void configure(TestSettings settings, ObjectNode integrationSettings) {
+        this.integrationSettings = integrationSettings;
+    }
+}

smithy-codegen-core/src/test/java/software/amazon/smithy/codegen/core/directed/CodegenDirectorTest.java

@@ -19,6 +19,9 @@
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.empty;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.notNullValue;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -33,6 +36,7 @@
 import software.amazon.smithy.model.Model;
 import software.amazon.smithy.model.node.ExpectationNotMetException;
 import software.amazon.smithy.model.node.Node;
+import software.amazon.smithy.model.node.ObjectNode;
 import software.amazon.smithy.model.shapes.ShapeId;
 
 public class CodegenDirectorTest {
@@ -42,6 +46,8 @@ private static final class TestDirected implements DirectedCodegen<TestContext,
         public final List<ShapeId> generatedEnumTypeEnums = new ArrayList<>();
         public final List<ShapeId> generatedStringTypeEnums = new ArrayList<>();
 
+        public final List<TestIntegration> integrations = new ArrayList<>();
+
         @Override
         public SymbolProvider createSymbolProvider(CreateSymbolProviderDirective<TestSettings> directive) {
             return shape -> Symbol.builder()
@@ -52,6 +58,8 @@ public SymbolProvider createSymbolProvider(CreateSymbolProviderDirective<TestSet
 
         @Override
         public TestContext createContext(CreateContextDirective<TestSettings, TestIntegration> directive) {
+            integrations.clear();
+            integrations.addAll(directive.integrations());
             WriterDelegator<TestWriter> delegator = new WriterDelegator<>(
                     directive.fileManifest(),
                     directive.symbolProvider(),
@@ -339,4 +347,40 @@ public void testShapesGenerationWithoutOrder() {
                 ShapeId.from("smithy.example#Foo")
         ));
     }
+
+    @Test
+    public void testConfiguresIntegrations() {
+        TestDirected testDirected = new TestDirected();
+        CodegenDirector<TestWriter, TestIntegration, TestContext, TestSettings> runner
+            = new CodegenDirector<>();
+        FileManifest manifest = new MockManifest();
+        Model model = Model.assembler()
+            .addImport(getClass().getResource("needs-sorting.smithy"))
+            .assemble()
+            .unwrap();
+
+        ObjectNode integrationSettings = Node.objectNode().withMember("spam", "eggs");
+        ObjectNode settings = Node.objectNode()
+            .withMember("foo", "hi")
+            .withMember("integrations", integrationSettings);
+        runner.settings(TestSettings.class, settings);
+        runner.directedCodegen(testDirected);
+        runner.fileManifest(manifest);
+        runner.service(ShapeId.from("smithy.example#Foo"));
+        runner.model(model);
+        runner.integrationClass(TestIntegration.class);
+        runner.performDefaultCodegenTransforms();
+        runner.shapeGenerationOrder(ShapeGenerationOrder.NONE);
+        runner.run();
+
+        assertThat(testDirected.integrations, not(empty()));
+        CapturingIntegration capturingIntegration = null;
+        for (TestIntegration integration : testDirected.integrations) {
+            if (integration instanceof CapturingIntegration) {
+                capturingIntegration = (CapturingIntegration) integration;
+            }
+        }
+        assertThat(capturingIntegration, notNullValue());
+        assertThat(capturingIntegration.integrationSettings, equalTo(integrationSettings));
+    }
 }

smithy-codegen-core/src/test/resources/META-INF/services/software.amazon.smithy.codegen.core.directed.TestIntegration

@@ -0,0 +1 @@
+software.amazon.smithy.codegen.core.directed.CapturingIntegration