Add more filters; open classes up (#1516)

Changes:
* generally remove `final` kw; open up classes for reuse
* add `as` as contextual ancestor snapshot version filter
* introduce version predicate filter
* redo `ns` and `rs` filters based on it

Author: cstamas

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/ChainedVersionFilter.java

@@ -29,7 +29,7 @@
  * A version filter that combines multiple version filters into a chain where each filter gets invoked one after the
  * other, thereby accumulating their filtering effects.
  */
-public final class ChainedVersionFilter implements VersionFilter {
+public class ChainedVersionFilter implements VersionFilter {
 
     private final VersionFilter[] filters;
 

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/ContextualAncestorSnapshotVersionFilter.java

@@ -0,0 +1,66 @@
+/*
+ * 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.eclipse.aether.util.graph.version;
+
+import org.eclipse.aether.artifact.Artifact;
+import org.eclipse.aether.collection.DependencyCollectionContext;
+import org.eclipse.aether.collection.VersionFilter;
+
+/**
+ * A version filter that blocks "*-SNAPSHOT" versions if the
+ * {@link VersionFilterContext#getDependency()} ancestor whose range is being filtered is not a snapshot.
+ */
+public class ContextualAncestorSnapshotVersionFilter implements VersionFilter {
+    private final SnapshotVersionFilter filter;
+
+    /**
+     * Creates a new instance of this version filter.
+     */
+    public ContextualAncestorSnapshotVersionFilter() {
+        filter = new SnapshotVersionFilter();
+    }
+
+    @Override
+    public void filterVersions(VersionFilterContext context) {
+        Artifact ancestor = context.getDependency().getArtifact();
+        if (!ancestor.isSnapshot()) {
+            filter.filterVersions(context);
+        }
+    }
+
+    @Override
+    public VersionFilter deriveChildFilter(DependencyCollectionContext context) {
+        return this;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        } else if (null == obj || !getClass().equals(obj.getClass())) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        return getClass().hashCode();
+    }
+}

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/ContextualSnapshotVersionFilter.java

@@ -28,11 +28,9 @@
 /**
  * A version filter that blocks "*-SNAPSHOT" versions if the
  * {@link org.eclipse.aether.collection.CollectRequest#getRootArtifact() root artifact} of the dependency graph is not a
- * snapshot. Alternatively, this filter can be forced to always ban snapshot versions by setting the boolean
- * {@link RepositorySystemSession#getConfigProperties() configuration property} {@link #CONFIG_PROP_ENABLE} to
- * {@code true}.
+ * snapshot.
  */
-public final class ContextualSnapshotVersionFilter implements VersionFilter {
+public class ContextualSnapshotVersionFilter implements VersionFilter {
     /**
      * The key in the repository session's {@link RepositorySystemSession#getConfigProperties() configuration
      * properties} used to store a {@link Boolean} flag whether this filter should be forced to ban snapshots. By
@@ -41,7 +39,9 @@ public final class ContextualSnapshotVersionFilter implements VersionFilter {
      * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
      * @configurationType {@link java.lang.Boolean}
      * @configurationDefaultValue false
+     * @deprecated Use snapshot filter instead to always ban snapshots.
      */
+    @Deprecated
     public static final String CONFIG_PROP_ENABLE = ConfigurationProperties.PREFIX_AETHER + "snapshotFilter";
 
     private final SnapshotVersionFilter filter;

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/HighestVersionFilter.java

@@ -27,7 +27,7 @@
 /**
  * A version filter that excludes any version except the highest one.
  */
-public final class HighestVersionFilter implements VersionFilter {
+public class HighestVersionFilter implements VersionFilter {
     private final int count;
 
     /**

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/LowestVersionFilter.java

@@ -29,7 +29,7 @@
  *
  * @since 2.0.0
  */
-public final class LowestVersionFilter implements VersionFilter {
+public class LowestVersionFilter implements VersionFilter {
     private final int count;
 
     /**

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/PredicateVersionFilter.java

@@ -34,7 +34,7 @@
  *
  * @since 2.0.0
  */
-public final class PredicateVersionFilter implements VersionFilter {
+public class PredicateVersionFilter implements VersionFilter {
     private final Predicate<Artifact> artifactPredicate;
 
     /**

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/ReleaseVersionFilter.java

@@ -0,0 +1,32 @@
+/*
+ * 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.eclipse.aether.util.graph.version;
+
+/**
+ * A version filter that (unconditionally) blocks non "*-SNAPSHOT" versions.
+ */
+public class ReleaseVersionFilter extends VersionPredicateVersionFilter {
+
+    /**
+     * Creates a new instance of this version filter.
+     */
+    public ReleaseVersionFilter() {
+        super(v -> v.toString().endsWith("SNAPSHOT"));
+    }
+}

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/SnapshotVersionFilter.java

@@ -18,50 +18,16 @@
  */
 package org.eclipse.aether.util.graph.version;
 
-import java.util.Iterator;
-
-import org.eclipse.aether.collection.DependencyCollectionContext;
-import org.eclipse.aether.collection.VersionFilter;
-import org.eclipse.aether.version.Version;
-
 /**
  * A version filter that (unconditionally) blocks "*-SNAPSHOT" versions. For practical purposes,
  * {@link ContextualSnapshotVersionFilter} is usually more desirable.
  */
-public final class SnapshotVersionFilter implements VersionFilter {
+public class SnapshotVersionFilter extends VersionPredicateVersionFilter {
 
     /**
      * Creates a new instance of this version filter.
      */
-    public SnapshotVersionFilter() {}
-
-    @Override
-    public void filterVersions(VersionFilterContext context) {
-        for (Iterator<Version> it = context.iterator(); it.hasNext(); ) {
-            String version = it.next().toString();
-            if (version.endsWith("SNAPSHOT")) {
-                it.remove();
-            }
-        }
-    }
-
-    @Override
-    public VersionFilter deriveChildFilter(DependencyCollectionContext context) {
-        return this;
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        } else if (null == obj || !getClass().equals(obj.getClass())) {
-            return false;
-        }
-        return true;
-    }
-
-    @Override
-    public int hashCode() {
-        return getClass().hashCode();
+    public SnapshotVersionFilter() {
+        super(v -> !v.toString().endsWith("SNAPSHOT"));
     }
 }

maven-resolver-util/src/main/java/org/eclipse/aether/util/graph/version/VersionPredicateVersionFilter.java

@@ -0,0 +1,77 @@
+/*
+ * 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.eclipse.aether.util.graph.version;
+
+import java.util.Iterator;
+import java.util.Objects;
+import java.util.function.Predicate;
+
+import org.eclipse.aether.collection.DependencyCollectionContext;
+import org.eclipse.aether.collection.VersionFilter;
+import org.eclipse.aether.version.Version;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * A version filter that excludes any version that is blacklisted.
+ *
+ * @since 2.0.11
+ */
+public class VersionPredicateVersionFilter implements VersionFilter {
+    private final Predicate<Version> versionPredicate;
+
+    /**
+     * Creates a new instance of this version filter. It will filter out versions not matched by predicate.
+     * Note: filter always operates with baseVersions.
+     */
+    public VersionPredicateVersionFilter(Predicate<Version> versionPredicate) {
+        this.versionPredicate = requireNonNull(versionPredicate);
+    }
+
+    @Override
+    public void filterVersions(VersionFilterContext context) {
+        for (Iterator<Version> it = context.iterator(); it.hasNext(); ) {
+            if (!versionPredicate.test(it.next())) {
+                it.remove();
+            }
+        }
+    }
+
+    @Override
+    public VersionFilter deriveChildFilter(DependencyCollectionContext context) {
+        return this;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        VersionPredicateVersionFilter that = (VersionPredicateVersionFilter) o;
+        return Objects.equals(versionPredicate, that.versionPredicate);
+    }
+
+    @Override
+    public int hashCode() {
+        return getClass().hashCode();
+    }
+}

maven-resolver-util/src/test/java/org/eclipse/aether/util/graph/versions/ReleaseVersionFilterTest.java

@@ -0,0 +1,53 @@
+/*
+ * 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.eclipse.aether.util.graph.versions;
+
+import org.eclipse.aether.collection.VersionFilter.VersionFilterContext;
+import org.eclipse.aether.util.graph.version.ReleaseVersionFilter;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+public class ReleaseVersionFilterTest extends AbstractVersionFilterTest {
+
+    @Test
+    void testFilterVersions() {
+        ReleaseVersionFilter filter = new ReleaseVersionFilter();
+        VersionFilterContext ctx = newContext("g:a:[1,9]", "1", "2-SNAPSHOT", "3.1", "4.0-SNAPSHOT", "5.0.0");
+        filter.filterVersions(ctx);
+        assertVersions(ctx, "2-SNAPSHOT", "4.0-SNAPSHOT");
+    }
+
+    @Test
+    void testDeriveChildFilter() {
+        ReleaseVersionFilter filter = new ReleaseVersionFilter();
+        assertSame(filter, derive(filter, "g:a:1"));
+    }
+
+    @SuppressWarnings("EqualsWithItself")
+    @Test
+    void testEquals() {
+        ReleaseVersionFilter filter = new ReleaseVersionFilter();
+        assertNotEquals(null, filter);
+        assertEquals(filter, filter);
+        assertEquals(filter, new ReleaseVersionFilter());
+    }
+}