add possibility to check for overriding methods to domain and lang

Resolves: #1198

Signed-off-by: Roland Weisleder <roland.weisleder@googlemail.com>

Author: rweisleder

archunit/src/main/java/com/tngtech/archunit/core/domain/JavaMethod.java

@@ -21,18 +21,29 @@
 import java.util.Set;
 import java.util.function.Function;
 import java.util.function.Supplier;
+import java.util.stream.Stream;
 
 import com.tngtech.archunit.PublicAPI;
 import com.tngtech.archunit.base.ArchUnitException.InconsistentClassPathException;
+import com.tngtech.archunit.base.DescribedPredicate;
 import com.tngtech.archunit.base.MayResolveTypesViaReflection;
 import com.tngtech.archunit.base.ResolvesTypesViaReflection;
 import com.tngtech.archunit.base.Suppliers;
+import com.tngtech.archunit.core.domain.properties.CanBeAnnotated;
+import com.tngtech.archunit.core.domain.properties.HasModifiers;
+import com.tngtech.archunit.core.domain.properties.HasName;
+import com.tngtech.archunit.core.domain.properties.HasOwner;
+import com.tngtech.archunit.core.domain.properties.HasParameterTypes;
+import com.tngtech.archunit.core.domain.properties.HasReturnType;
+import com.tngtech.archunit.core.domain.properties.HasThrowsClause;
 import com.tngtech.archunit.core.importer.DomainBuilders;
 
 import static com.google.common.collect.Sets.union;
 import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
+import static com.tngtech.archunit.base.DescribedPredicate.describe;
 import static com.tngtech.archunit.core.domain.Formatters.formatMethod;
 import static com.tngtech.archunit.core.domain.properties.HasName.Utils.namesOf;
+import static java.util.stream.Collectors.toList;
 
 @PublicAPI(usage = ACCESS)
 public final class JavaMethod extends JavaCodeUnit {
@@ -126,6 +137,30 @@ public String getDescription() {
         return "Method <" + getFullName() + ">";
     }
 
+    /**
+     * Returns true, if this method overrides or implements a method from a supertype.
+     * The annotation {@link Override} may or may not be present on this method.
+     *
+     * @see Override
+     */
+    @PublicAPI(usage = ACCESS)
+    public boolean isOverriding() {
+        List<JavaClass> supertypes = Stream.concat(
+                getOwner().getAllRawSuperclasses().stream(),
+                getOwner().getAllRawInterfaces().stream()
+        ).collect(toList());
+
+        String name = getName();
+        String[] parameterTypes = getRawParameterTypes().stream().map(JavaClass::getFullName).toArray(String[]::new);
+        for (JavaClass supertype : supertypes) {
+            if (supertype.tryGetMethod(name, parameterTypes).isPresent()) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     @ResolvesTypesViaReflection
     @MayResolveTypesViaReflection(reason = "Just part of a bigger resolution process")
     private class ReflectMethodSupplier implements Supplier<Method> {
@@ -141,4 +176,33 @@ public Method get() {
         }
     }
 
+    /**
+     * Predefined {@link DescribedPredicate predicates} targeting {@link JavaMethod}.
+     * Note that due to inheritance further predicates for {@link JavaMethod} can be found in the following locations:
+     * <ul>
+     *     <li>{@link JavaCodeUnit.Predicates}</li>
+     *     <li>{@link JavaMember.Predicates}</li>
+     *     <li>{@link HasName.Predicates}</li>
+     *     <li>{@link HasName.AndFullName.Predicates}</li>
+     *     <li>{@link HasModifiers.Predicates}</li>
+     *     <li>{@link CanBeAnnotated.Predicates}</li>
+     *     <li>{@link HasOwner.Predicates}</li>
+     *     <li>{@link HasParameterTypes.Predicates}</li>
+     *     <li>{@link HasReturnType.Predicates}</li>
+     *     <li>{@link HasThrowsClause.Predicates}</li>
+     * </ul>
+     */
+    @PublicAPI(usage = ACCESS)
+    public static final class Predicates {
+        private Predicates() {
+        }
+
+        /**
+         * @see JavaMethod#isOverriding()
+         */
+        @PublicAPI(usage = ACCESS)
+        public static DescribedPredicate<JavaMethod> overriding() {
+            return describe("overriding", JavaMethod::isOverriding);
+        }
+    }
 }

archunit/src/main/java/com/tngtech/archunit/lang/syntax/MethodsShouldInternal.java

@@ -24,6 +24,10 @@
 import com.tngtech.archunit.lang.syntax.elements.MethodsShould;
 import com.tngtech.archunit.lang.syntax.elements.MethodsShouldConjunction;
 
+import static com.tngtech.archunit.core.domain.JavaMethod.Predicates.overriding;
+import static com.tngtech.archunit.lang.conditions.ArchConditions.be;
+import static com.tngtech.archunit.lang.conditions.ArchConditions.not;
+
 class MethodsShouldInternal
         extends AbstractCodeUnitsShouldInternal<JavaMethod, MethodsShouldInternal>
         implements MethodsShould<MethodsShouldInternal>, MethodsShouldConjunction {
@@ -58,4 +62,14 @@ private MethodsShouldInternal(
     MethodsShouldInternal copyWithNewCondition(ConditionAggregator<JavaMethod> newCondition) {
         return new MethodsShouldInternal(classesTransformer, priority, newCondition, prepareCondition);
     }
+
+    @Override
+    public MethodsShouldInternal beOverriding() {
+        return addCondition(be(overriding()));
+    }
+
+    @Override
+    public MethodsShouldInternal notBeOverriding() {
+        return addCondition(not(be(overriding())));
+    }
 }

archunit/src/main/java/com/tngtech/archunit/lang/syntax/MethodsThatInternal.java

@@ -15,14 +15,33 @@
  */
 package com.tngtech.archunit.lang.syntax;
 
+import com.tngtech.archunit.base.DescribedPredicate;
 import com.tngtech.archunit.core.domain.JavaMethod;
 import com.tngtech.archunit.lang.syntax.elements.MethodsThat;
 
+import static com.tngtech.archunit.base.DescribedPredicate.not;
+import static com.tngtech.archunit.core.domain.JavaMethod.Predicates.overriding;
+import static com.tngtech.archunit.lang.conditions.ArchPredicates.are;
+
 class MethodsThatInternal
         extends CodeUnitsThatInternal<JavaMethod, GivenMethodsInternal>
         implements MethodsThat<GivenMethodsInternal> {
 
     MethodsThatInternal(GivenMethodsInternal givenMethods, PredicateAggregator<JavaMethod> currentPredicate) {
         super(givenMethods, currentPredicate);
     }
+
+    @Override
+    public GivenMethodsInternal areOverriding() {
+        return withPredicate(are(overriding()));
+    }
+
+    @Override
+    public GivenMethodsInternal areNotOverriding() {
+        return withPredicate(are(not(overriding())));
+    }
+
+    private GivenMethodsInternal withPredicate(DescribedPredicate<JavaMethod> predicate) {
+        return givenMembers.with(currentPredicate.add(predicate));
+    }
 }

archunit/src/main/java/com/tngtech/archunit/lang/syntax/elements/MethodsShould.java

@@ -16,6 +16,7 @@
 package com.tngtech.archunit.lang.syntax.elements;
 
 import com.tngtech.archunit.PublicAPI;
+import com.tngtech.archunit.core.domain.JavaMethod;
 
 import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
 
@@ -53,4 +54,22 @@ public interface MethodsShould<CONJUNCTION extends MethodsShouldConjunction> ext
      */
     @PublicAPI(usage = ACCESS)
     CONJUNCTION notBeFinal();
+
+    /**
+     * Asserts that methods override other methods.
+     *
+     * @return A syntax element that can either be used as working rule, or to continue specifying a more complex rule
+     * @see JavaMethod#isOverriding()
+     */
+    @PublicAPI(usage = ACCESS)
+    CONJUNCTION beOverriding();
+
+    /**
+     * Asserts that methods do not override other methods.
+     *
+     * @return A syntax element that can either be used as working rule, or to continue specifying a more complex rule
+     * @see JavaMethod#isOverriding()
+     */
+    @PublicAPI(usage = ACCESS)
+    CONJUNCTION notBeOverriding();
 }

archunit/src/main/java/com/tngtech/archunit/lang/syntax/elements/MethodsThat.java

@@ -16,6 +16,7 @@
 package com.tngtech.archunit.lang.syntax.elements;
 
 import com.tngtech.archunit.PublicAPI;
+import com.tngtech.archunit.core.domain.JavaMethod;
 
 import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
 
@@ -53,4 +54,22 @@ public interface MethodsThat<CONJUNCTION> extends CodeUnitsThat<CONJUNCTION> {
      */
     @PublicAPI(usage = ACCESS)
     CONJUNCTION areNotFinal();
+
+    /**
+     * Matches methods that override other methods.
+     *
+     * @return A syntax conjunction element, which can be completed to form a full rule
+     * @see JavaMethod#isOverriding()
+     */
+    @PublicAPI(usage = ACCESS)
+    CONJUNCTION areOverriding();
+
+    /**
+     * Matches methods that do not override other methods.
+     *
+     * @return A syntax conjunction element, which can be completed to form a full rule
+     * @see JavaMethod#isOverriding()
+     */
+    @PublicAPI(usage = ACCESS)
+    CONJUNCTION areNotOverriding();
 }

archunit/src/test/java/com/tngtech/archunit/core/domain/JavaMethodTest.java

@@ -0,0 +1,59 @@
+package com.tngtech.archunit.core.domain;
+
+import org.junit.Test;
+
+import static com.tngtech.archunit.core.domain.TestUtils.importMethod;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JavaMethodTest {
+
+    @Test
+    public void isOverriding_returns_true_for_implemented_interface_method() {
+        assertThat(importMethod(SomeClass.class, "doSomething").isOverriding()).isTrue();
+    }
+
+    @Test
+    public void isOverriding_returns_false_for_interface_method() {
+        assertThat(importMethod(SomeInterface.class, "doSomething").isOverriding()).isFalse();
+    }
+
+    @Test
+    public void isOverriding_returns_true_for_overriding_method_of_java_lang_Object() {
+        assertThat(importMethod(SomeClass.class, "toString").isOverriding()).isTrue();
+    }
+
+    @Test
+    public void isOverriding_returns_false_for_non_overriding_method() {
+        assertThat(importMethod(SomeClass.class, "doSomethingElse").isOverriding()).isFalse();
+    }
+
+    @Test
+    public void isOverriding_returns_false_for_non_overriding_overloaded_method() {
+        assertThat(importMethod(SomeClass.class, "doSomething", Object.class).isOverriding()).isFalse();
+    }
+
+    @SuppressWarnings("unused")
+    private interface SomeInterface {
+
+        void doSomething();
+    }
+
+    @SuppressWarnings("unused")
+    private static class SomeClass implements SomeInterface {
+
+        @Override
+        public void doSomething() {
+        }
+
+        public void doSomething(Object o) {
+        }
+
+        public void doSomethingElse() {
+        }
+
+        @Override
+        public String toString() {
+            return super.toString();
+        }
+    }
+}

archunit/src/test/java/com/tngtech/archunit/lang/syntax/elements/GivenMethodsTest.java

@@ -27,6 +27,8 @@ public static Object[][] restricted_property_rule_starts() {
                 $(described(methods().that().areNotFinal()), ImmutableSet.of(METHOD_C, METHOD_D)),
                 $(described(methods().that().areStatic()), ImmutableSet.of(METHOD_B, METHOD_D)),
                 $(described(methods().that().areNotStatic()), ImmutableSet.of(METHOD_A, METHOD_C)),
+                $(described(methods().that().areOverriding()), ImmutableSet.of(METHOD_A)),
+                $(described(methods().that().areNotOverriding()), ImmutableSet.of(METHOD_B, METHOD_C, METHOD_D)),
                 $(described(methods().that().areFinal().and().areStatic()), ImmutableSet.of(METHOD_B)),
                 $(described(methods().that().areFinal().or().areStatic()), ImmutableSet.of(METHOD_A, METHOD_B, METHOD_D))
         );
@@ -47,7 +49,7 @@ public void property_predicates(DescribedRuleStart ruleStart, Collection<String>
     private static final String METHOD_D = "methodD()";
 
     @SuppressWarnings({"unused"})
-    private static class ClassWithVariousMembers {
+    private static class ClassWithVariousMembers extends SuperclassWithVariousMembers {
         public final void methodA(int[] array) {
         }
         protected static final void methodB(boolean flag) {
@@ -58,4 +60,10 @@ static int methodD() {
             return 0;
         }
     }
+
+    @SuppressWarnings("unused")
+    private static class SuperclassWithVariousMembers {
+        public void methodA(int[] array) {
+        }
+    }
 }

archunit/src/test/java/com/tngtech/archunit/lang/syntax/elements/MethodsShouldTest.java

@@ -29,6 +29,8 @@ public static Object[][] restricted_property_rule_ends() {
                 $(methods().should().notBeFinal(), ImmutableSet.of(METHOD_A, METHOD_B)),
                 $(methods().should().beStatic(), ImmutableSet.of(METHOD_A, METHOD_C)),
                 $(methods().should().notBeStatic(), ImmutableSet.of(METHOD_B, METHOD_D)),
+                $(methods().should().beOverriding(), ImmutableSet.of(METHOD_B, METHOD_C, METHOD_D)),
+                $(methods().should().notBeOverriding(), ImmutableSet.of(METHOD_A)),
                 $(methods().should().notBeFinal().andShould().notBeStatic(), ImmutableSet.of(METHOD_A, METHOD_B, METHOD_D)),
                 $(methods().should().notBeFinal().orShould().notBeStatic(), ImmutableSet.of(METHOD_B))
         );
@@ -49,7 +51,7 @@ public void property_predicates(ArchRule ruleStart, Collection<String> expectedM
     private static final String METHOD_D = "methodD()";
 
     @SuppressWarnings({"unused"})
-    private static class ClassWithVariousMembers {
+    private static class ClassWithVariousMembers extends SuperclassWithVariousMembers {
         public final void methodA(int[] array) {
         }
         protected static final void methodB(boolean flag) {
@@ -60,4 +62,10 @@ static int methodD() {
             return 0;
         }
     }
+
+    @SuppressWarnings("unused")
+    private static class SuperclassWithVariousMembers {
+        public void methodA(int[] array) {
+        }
+    }
 }