Made some API collection return types more specific, since it integra…

…tes nicer with JDK >= 8 streams. Also introduced ArchUnit's own ForwardingCollection/-Set, since we don't want to have Guava in the public API (sneakily leaked through Slice).

Signed-off-by: Peter Gafert <[email protected]>

archunit-integration-test/src/test/java/com/tngtech/archunit/PublicAPIRules.java

@@ -13,6 +13,7 @@
 import com.tngtech.archunit.junit.ArchUnitRunner;
 import com.tngtech.archunit.lang.ArchCondition;
 import com.tngtech.archunit.lang.ArchRule;
+import com.tngtech.archunit.lang.CompositeArchRule;
 import com.tngtech.archunit.lang.ConditionEvents;
 import com.tngtech.archunit.lang.SimpleConditionEvent;
 import com.tngtech.archunit.lang.syntax.ArchRuleDefinition;
@@ -101,6 +102,16 @@ public class PublicAPIRules {
                     .and().doNotHaveName("adhereToPlantUmlDiagram")
                     .should().haveRawParameterTypes(thatArePublic());
 
+    @ArchTest
+    public static final ArchRule Guava_should_not_leak_into_public_API =
+            CompositeArchRule.of(
+                    classes().that(publicAPI()).should().notBeAssignableTo(guavaClass()))
+                    .and(codeUnits()
+                            .that().arePublic()
+                            .and().areDeclaredInClassesThat(are(publicAPI()))
+                            .should().haveRawParameterTypes(withoutGuava())
+                            .andShould().haveRawReturnType(not(guavaClass()).as("that are no Guava types")));
+
     private static DescribedPredicate<JavaClass> publicAPI() {
         return annotatedWith(PublicAPI.class).<JavaClass>forSubType()
                 .or(haveMemberThatBelongsToPublicApi())
@@ -316,4 +327,28 @@ public boolean apply(List<JavaClass> input) {
             }
         };
     }
+
+    private static DescribedPredicate<JavaClass> guavaClass() {
+        return JavaClass.Functions.GET_PACKAGE_NAME.is(
+                new DescribedPredicate<String>("") {
+                    @Override
+                    public boolean apply(String input) {
+                        return input.contains(".google.");
+                    }
+                }).as("Guava Class");
+    }
+
+    private static DescribedPredicate<List<JavaClass>> withoutGuava() {
+        return new DescribedPredicate<List<JavaClass>>("without Guava") {
+            @Override
+            public boolean apply(List<JavaClass> input) {
+                for (JavaClass parameterType : input) {
+                    if (guavaClass().apply(parameterType)) {
+                        return false;
+                    }
+                }
+                return true;
+            }
+        };
+    }
 }

archunit/src/main/java/com/tngtech/archunit/base/ForwardingCollection.java

@@ -0,0 +1,125 @@
+/*
+ * Copyright 2019 TNG Technology Consulting GmbH
+ *
+ * Licensed 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 com.tngtech.archunit.base;
+
+import java.util.Collection;
+import java.util.Iterator;
+
+import com.tngtech.archunit.PublicAPI;
+
+import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
+
+@PublicAPI(usage = ACCESS)
+public abstract class ForwardingCollection<T> implements Collection<T> {
+    protected ForwardingCollection() {
+    }
+
+    protected abstract Collection<T> delegate();
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public int size() {
+        return delegate().size();
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean isEmpty() {
+        return delegate().isEmpty();
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean contains(Object o) {
+        return delegate().contains(o);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public Iterator<T> iterator() {
+        return delegate().iterator();
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public Object[] toArray() {
+        return delegate().toArray();
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    @SuppressWarnings("SuspiciousToArrayCall")
+    public <T1> T1[] toArray(T1[] a) {
+        return delegate().toArray(a);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean add(T t) {
+        return delegate().add(t);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean remove(Object o) {
+        return delegate().remove(o);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean containsAll(Collection<?> c) {
+        return delegate().containsAll(c);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean addAll(Collection<? extends T> c) {
+        return delegate().addAll(c);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean removeAll(Collection<?> c) {
+        return delegate().removeAll(c);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean retainAll(Collection<?> c) {
+        return delegate().retainAll(c);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public void clear() {
+        delegate().clear();
+    }
+
+    @Override
+    public int hashCode() {
+        return delegate().hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        return obj == this || delegate().equals(obj);
+    }
+
+    @Override
+    public String toString() {
+        return delegate().toString();
+    }
+}

archunit/src/main/java/com/tngtech/archunit/base/ForwardingList.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2019 TNG Technology Consulting GmbH
+ *
+ * Licensed 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 com.tngtech.archunit.base;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.ListIterator;
+
+import com.tngtech.archunit.PublicAPI;
+
+import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
+
+@PublicAPI(usage = ACCESS)
+public abstract class ForwardingList<T> extends ForwardingCollection<T> implements List<T> {
+    protected ForwardingList() {
+    }
+
+    @Override
+    protected abstract List<T> delegate();
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public boolean addAll(int index, Collection<? extends T> c) {
+        return delegate().addAll(index, c);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public T get(int index) {
+        return delegate().get(index);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public T set(int index, T element) {
+        return delegate().set(index, element);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public void add(int index, T element) {
+        delegate().add(index, element);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public T remove(int index) {
+        return delegate().remove(index);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public int indexOf(Object o) {
+        return delegate().indexOf(o);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public int lastIndexOf(Object o) {
+        return delegate().lastIndexOf(o);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public ListIterator<T> listIterator() {
+        return delegate().listIterator();
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public ListIterator<T> listIterator(int index) {
+        return delegate().listIterator(index);
+    }
+
+    @Override
+    @PublicAPI(usage = ACCESS)
+    public List<T> subList(int fromIndex, int toIndex) {
+        return delegate().subList(fromIndex, toIndex);
+    }
+}

archunit/src/main/java/com/tngtech/archunit/base/ForwardingSet.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2019 TNG Technology Consulting GmbH
+ *
+ * Licensed 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 com.tngtech.archunit.base;
+
+import java.util.Set;
+
+import com.tngtech.archunit.PublicAPI;
+
+import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
+
+@PublicAPI(usage = ACCESS)
+public abstract class ForwardingSet<T> extends ForwardingCollection<T> implements Set<T> {
+    protected ForwardingSet() {
+    }
+
+    @Override
+    protected abstract Set<T> delegate();
+}