[MNG-8006] SPI to contribute to effective properties and more

api/maven-api-core/src/main/java/org/apache/maven/api/Project.java

@@ -20,6 +20,7 @@
 
 import java.nio.file.Path;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 
 import org.apache.maven.api.annotations.Experimental;
@@ -133,4 +134,10 @@ default String getId() {
 
     @Nonnull
     List<RemoteRepository> getRemotePluginRepositories();
+
+    /**
+     * Returns the effective project properties.
+     */
+    @Nonnull
+    Map<String, String> getProperties();
 }

api/maven-api-core/src/main/java/org/apache/maven/api/Session.java

@@ -28,6 +28,7 @@
 
 import org.apache.maven.api.annotations.Experimental;
 import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.annotations.Nullable;
 import org.apache.maven.api.annotations.ThreadSafe;
 import org.apache.maven.api.model.Repository;
 import org.apache.maven.api.services.DependencyCoordinateFactory;
@@ -73,15 +74,12 @@ public interface Session {
     Map<String, String> getSystemProperties();
 
     /**
-     * Gets the immutable effective properties to use for interpolation. The effective properties are collected from
-     * {@link #getSystemProperties()} and {@link #getUserProperties()} in this order, and more.
-     * <p>
-     * These properties are "effective" in a way they are built obeying all "user overrides" and others.
+     * Gets the effective properties to use for interpolation.
      *
-     * @return the config properties, never {@code null}
+     * @return the effective properties, never {@code null}
      */
     @Nonnull
-    Map<String, Object> getEffectiveProperties();
+    Map<String, String> getEffectiveProperties(@Nullable Project project);
 
     /**
      * Returns the current maven version

api/maven-api-core/src/main/java/org/apache/maven/api/services/Properties.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.maven.api.services;
+
+import java.util.Map;
+
+import org.apache.maven.api.*;
+import org.apache.maven.api.annotations.Experimental;
+import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.annotations.Nullable;
+
+/**
+ * @since 4.0.0
+ */
+@Experimental
+public interface Properties extends Service {
+
+    /**
+     * Creates a {@link org.apache.maven.api.Project} from a POM file.
+     *
+     * @param project {@link Project} or {@code null}.
+     * @return the {@link Map} containing the effective properties.
+     * @throws IllegalArgumentException if an argument is {@code null} or invalid
+     */
+    @Nonnull
+    Map<String, String> effectiveProperties(@Nonnull Session session, @Nullable Project project);
+}

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultProject.java

@@ -20,10 +20,7 @@
 
 import java.io.File;
 import java.nio.file.Path;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.Optional;
+import java.util.*;
 
 import org.apache.maven.RepositoryUtils;
 import org.apache.maven.api.*;
@@ -154,6 +151,11 @@ public List<RemoteRepository> getRemotePluginRepositories() {
         return new MappedList<>(project.getRemotePluginRepositories(), session::getRemoteRepository);
     }
 
+    @Override
+    public Map<String, String> getProperties() {
+        return new PropertiesAsMap(project.getProperties());
+    }
+
     @Nonnull
     private DependencyCoordinate toDependency(org.apache.maven.api.model.Dependency dependency) {
         return new DependencyCoordinate() {

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultProperties.java

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.maven.internal.impl;
+
+import javax.inject.Named;
+import javax.inject.Singleton;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.maven.api.Project;
+import org.apache.maven.api.Session;
+import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.annotations.Nullable;
+import org.apache.maven.api.services.*;
+
+import static org.apache.maven.internal.impl.Utils.nonNull;
+
+@Named
+@Singleton
+public class DefaultProperties implements Properties {
+    @Nonnull
+    @Override
+    public Map<String, String> effectiveProperties(@Nonnull Session session, @Nullable Project project) {
+        nonNull(session);
+        HashMap<String, String> result = new HashMap<>(session.getSystemProperties());
+        if (project != null) {
+            result.putAll(project.getProperties());
+        }
+        result.putAll(session.getUserProperties());
+        return result;
+    }
+}

maven-core/src/main/java/org/apache/maven/internal/impl/DefaultSession.java

@@ -35,6 +35,7 @@
 import org.apache.maven.api.services.Lookup;
 import org.apache.maven.api.services.LookupException;
 import org.apache.maven.api.services.MavenException;
+import org.apache.maven.api.services.Properties;
 import org.apache.maven.api.settings.Settings;
 import org.apache.maven.artifact.repository.ArtifactRepository;
 import org.apache.maven.bridge.MavenRepositorySystem;
@@ -107,19 +108,19 @@ public Settings getSettings() {
     @Nonnull
     @Override
     public Map<String, String> getUserProperties() {
-        return session.getUserProperties();
+        return new PropertiesAsMap(mavenSession.getUserProperties());
     }
 
     @Nonnull
     @Override
     public Map<String, String> getSystemProperties() {
-        return session.getSystemProperties();
+        return new PropertiesAsMap(mavenSession.getSystemProperties());
     }
 
     @Nonnull
     @Override
-    public Map<String, Object> getEffectiveProperties() {
-        return session.getConfigProperties();
+    public Map<String, String> getEffectiveProperties(@Nullable Project project) {
+        return getService(Properties.class).effectiveProperties(this, project);
     }
 
     @Nonnull

maven-core/src/main/java/org/apache/maven/plugin/PluginParameterExpressionEvaluatorV4.java

@@ -24,7 +24,6 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Properties;
 
 import org.apache.maven.api.MojoExecution;
 import org.apache.maven.api.Project;
@@ -54,15 +53,15 @@
  * @see MojoExecution
  */
 public class PluginParameterExpressionEvaluatorV4 implements TypeAwareExpressionEvaluator {
-    private Session session;
+    private final Session session;
 
-    private MojoExecution mojoExecution;
+    private final MojoExecution mojoExecution;
 
-    private Project project;
+    private final Project project;
 
-    private Path basedir;
+    private final Path basedir;
 
-    private Properties properties;
+    private final Map<String, String> properties;
 
     public PluginParameterExpressionEvaluatorV4(Session session, Project project) {
         this(session, project, null);
@@ -71,16 +70,9 @@ public PluginParameterExpressionEvaluatorV4(Session session, Project project) {
     public PluginParameterExpressionEvaluatorV4(Session session, Project project, MojoExecution mojoExecution) {
         this.session = session;
         this.mojoExecution = mojoExecution;
-        this.properties = new Properties();
+        this.properties = session.getEffectiveProperties(project);
         this.project = project;
 
-        //
-        // Maven4: We may want to evaluate how this is used but we add these separate as the
-        // getExecutionProperties is deprecated in MavenSession.
-        //
-        this.properties.putAll(session.getUserProperties());
-        this.properties.putAll(session.getSystemProperties());
-
         Path basedir = null;
 
         if (project != null) {
@@ -198,11 +190,7 @@ public Object evaluate(String expr, Class<?> type) throws ExpressionEvaluationEx
                 // to run a single test so I want to specify that class on the cli as
                 // a parameter.
 
-                value = properties.getProperty(expression);
-            }
-
-            if ((value == null) && ((project != null) && (project.getModel().getProperties() != null))) {
-                value = project.getModel().getProperties().get(expression);
+                value = properties.get(expression);
             }
         }
 

maven-core/src/test/java/org/apache/maven/AbstractCoreMavenComponentTestCase.java

@@ -34,6 +34,7 @@
 import org.apache.maven.execution.DefaultMavenExecutionResult;
 import org.apache.maven.execution.MavenExecutionRequest;
 import org.apache.maven.execution.MavenSession;
+import org.apache.maven.internal.impl.DefaultLookup;
 import org.apache.maven.internal.impl.DefaultSessionFactory;
 import org.apache.maven.model.Build;
 import org.apache.maven.model.Dependency;
@@ -147,7 +148,7 @@ protected MavenSession createMavenSession(File pom, Properties executionProperti
         initRepoSession(configuration);
 
         DefaultSessionFactory defaultSessionFactory =
-                new DefaultSessionFactory(mock(RepositorySystem.class), null, null, null);
+                new DefaultSessionFactory(mock(RepositorySystem.class), null, new DefaultLookup(container), null);
 
         MavenSession session = new MavenSession(
                 getContainer(), configuration.getRepositorySession(), request, new DefaultMavenExecutionResult());