fix confusing behavior of only{Call/Access}...That... syntax

To make assertions about access targets is in general not trivial. From the byte code we can only infer that the method `x` with some signature was called on target class `y`. This does not give us enough information to make assertions about the method itself (thus ArchUnit distinguishes an `AccessTarget` having a name and an owner where it is declared from a full `JavaMember` which can also have e.g. annotations, an information that cannot be derived from the mere byte code access).
Syntax elements of the form `only{Call/Access}...That...`, which want to apply a predicate to some subclass of `JavaMember`, must thus try to resolve the actual call of a target first (by calling `target.resolve()` which will in some cases even report multiple targets, but can also return no target at all, e.g. if the target class has not been imported and thus there is no information about the full method). So far these methods have asserted that at least one element of the resolved targets satisfies the predicate. Unfortunately this will fail and report a violation whenever the target has not been imported, which is a somewhat confusing behavior. Originally I thought it would be good, because if one wants to make assertions about the resolved targets, one should ensure all targets are present and if not failure is okay. But on the one hand the error message is pretty confusing (which by itself would be fixable), on the other hand there are simply classes that cannot be correctly imported, for example array types. Since this behavior is confusing I have decided to let the test pass if the target cannot be resolved. This could lead to tests wrongly passing if not all necessary classes are imported, but in the end it is an user decision what to import and hard to reason about from ArchUnit's point of view (also now that `resolveMissingClassesFromClasspath` is `true` by default, it should also happen way less often, that necessary classes are forgotten for the import).

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

Author: codecholeric

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

@@ -282,9 +282,6 @@ Stream<DynamicTest> ControllerRulesTest() {
                 .by(callFromMethod(SomeController.class, "doSthController")
                         .toMethod(ServiceViolatingDaoRules.class, "doSthService")
                         .inLine(11))
-                .by(callFromMethod(SomeEnum.class, "values")
-                        .toMethod(SomeEnum[].class, "clone")
-                        .inLine(3))
 
                 .ofRule(String.format("classes that reside in a package '..controller..' should "
                                 + "only call constructors that are declared in a package '..controller..' or are annotated with @%s",
@@ -308,9 +305,6 @@ Stream<DynamicTest> ControllerRulesTest() {
                 .by(callFromConstructor(UseCaseTwoController.class)
                         .toConstructor(AbstractController.class)
                         .inLine(6))
-                .by(callFromMethod(SomeEnum.class, "values")
-                        .toMethod(SomeEnum[].class, "clone")
-                        .inLine(3))
 
                 .ofRule(String.format("classes that reside in a package '..controller..' should "
                                 + "only access fields that are declared in a package '..controller..' or are annotated with @%s",
@@ -334,9 +328,6 @@ Stream<DynamicTest> ControllerRulesTest() {
                 .by(callFromConstructor(UseCaseTwoController.class)
                         .toConstructor(AbstractController.class)
                         .inLine(6))
-                .by(callFromMethod(SomeEnum.class, "values")
-                        .toMethod(SomeEnum[].class, "clone")
-                        .inLine(3))
 
                 .toDynamicTests();
     }

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

@@ -15,6 +15,7 @@
  */
 package com.tngtech.archunit.base;
 
+import com.google.common.collect.Iterables;
 import com.tngtech.archunit.PublicAPI;
 
 import static com.google.common.base.Preconditions.checkArgument;
@@ -128,6 +129,10 @@ public static <T> DescribedPredicate<T> not(final DescribedPredicate<? super T>
         return new NotPredicate<>(predicate);
     }
 
+    public static DescribedPredicate<Iterable<?>> empty() {
+        return new EmptyPredicate();
+    }
+
     public static <T> DescribedPredicate<Iterable<T>> anyElementThat(final DescribedPredicate<? super T> predicate) {
         return new AnyElementPredicate<>(predicate);
     }
@@ -296,6 +301,17 @@ public boolean apply(T input) {
         }
     }
 
+    private static class EmptyPredicate extends DescribedPredicate<Iterable<?>> {
+        EmptyPredicate() {
+            super("empty");
+        }
+
+        @Override
+        public boolean apply(Iterable<?> input) {
+            return Iterables.isEmpty(input);
+        }
+    }
+
     private static class AnyElementPredicate<T> extends DescribedPredicate<Iterable<T>> {
         private final DescribedPredicate<T> predicate;
 

archunit/src/main/java/com/tngtech/archunit/lang/conditions/ArchConditions.java

@@ -65,6 +65,7 @@
 
 import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
 import static com.tngtech.archunit.base.DescribedPredicate.anyElementThat;
+import static com.tngtech.archunit.base.DescribedPredicate.empty;
 import static com.tngtech.archunit.core.domain.Dependency.Functions.GET_ORIGIN_CLASS;
 import static com.tngtech.archunit.core.domain.Dependency.Functions.GET_TARGET_CLASS;
 import static com.tngtech.archunit.core.domain.Dependency.Predicates.dependencyOrigin;
@@ -169,7 +170,7 @@ public static ArchCondition<JavaClass> accessFieldWhere(DescribedPredicate<? sup
     public static ArchCondition<JavaClass> onlyAccessFieldsThat(final DescribedPredicate<? super JavaField> predicate) {
         ChainableFunction<JavaFieldAccess, FieldAccessTarget> getTarget = JavaAccess.Functions.Get.target();
         DescribedPredicate<JavaFieldAccess> accessPredicate = getTarget.then(FieldAccessTarget.Functions.RESOLVE)
-                .is(anyElementThat(predicate.<JavaField>forSubType()));
+                .is(anyElementThat(predicate.<JavaField>forSubType()).or(empty()));
         return new ClassOnlyAccessesCondition<>(accessPredicate, GET_FIELD_ACCESSES_FROM_SELF)
                 .as("only access fields that " + predicate.getDescription());
     }
@@ -202,7 +203,7 @@ public static ArchCondition<JavaClass> callMethodWhere(final DescribedPredicate<
     public static ArchCondition<JavaClass> onlyCallMethodsThat(final DescribedPredicate<? super JavaMethod> predicate) {
         ChainableFunction<JavaMethodCall, MethodCallTarget> getTarget = JavaAccess.Functions.Get.target();
         DescribedPredicate<JavaMethodCall> callPredicate = getTarget.then(MethodCallTarget.Functions.RESOLVE)
-                .is(anyElementThat(predicate.<JavaMethod>forSubType()));
+                .is(anyElementThat(predicate.<JavaMethod>forSubType()).or(empty()));
         return new ClassOnlyAccessesCondition<>(callPredicate, GET_METHOD_CALLS_FROM_SELF)
                 .as("only call methods that " + predicate.getDescription());
     }
@@ -235,7 +236,7 @@ public static ArchCondition<JavaClass> callConstructorWhere(final DescribedPredi
     public static ArchCondition<JavaClass> onlyCallConstructorsThat(final DescribedPredicate<? super JavaConstructor> predicate) {
         ChainableFunction<JavaConstructorCall, ConstructorCallTarget> getTarget = JavaAccess.Functions.Get.target();
         DescribedPredicate<JavaConstructorCall> callPredicate = getTarget.then(ConstructorCallTarget.Functions.RESOLVE)
-                .is(anyElementThat(predicate.<JavaConstructor>forSubType()));
+                .is(anyElementThat(predicate.<JavaConstructor>forSubType()).or(empty()));
         return new ClassOnlyAccessesCondition<>(callPredicate, GET_CONSTRUCTOR_CALLS_FROM_SELF)
                 .as("only call constructors that " + predicate.getDescription());
     }
@@ -250,7 +251,7 @@ public static ArchCondition<JavaClass> callCodeUnitWhere(DescribedPredicate<? su
     public static ArchCondition<JavaClass> onlyCallCodeUnitsThat(final DescribedPredicate<? super JavaCodeUnit> predicate) {
         ChainableFunction<JavaCall<?>, CodeUnitCallTarget> getTarget = JavaAccess.Functions.Get.target();
         DescribedPredicate<JavaCall<?>> callPredicate = getTarget.then(CodeUnitCallTarget.Functions.RESOLVE)
-                .is(anyElementThat(predicate.<JavaCodeUnit>forSubType()));
+                .is(anyElementThat(predicate.<JavaCodeUnit>forSubType()).or(empty()));
         return new ClassOnlyAccessesCondition<>(callPredicate, GET_CALLS_FROM_SELF)
                 .as("only call code units that " + predicate.getDescription());
     }
@@ -259,7 +260,7 @@ public static ArchCondition<JavaClass> onlyCallCodeUnitsThat(final DescribedPred
     public static ArchCondition<JavaClass> onlyAccessMembersThat(final DescribedPredicate<? super JavaMember> predicate) {
         ChainableFunction<JavaAccess<?>, AccessTarget> getTarget = JavaAccess.Functions.Get.target();
         DescribedPredicate<JavaAccess<?>> accessPredicate = getTarget.then(AccessTarget.Functions.RESOLVE)
-                .is(anyElementThat(predicate.<JavaMember>forSubType()));
+                .is(anyElementThat(predicate.<JavaMember>forSubType()).or(empty()));
         return new ClassOnlyAccessesCondition<>(accessPredicate, GET_ACCESSES_FROM_SELF)
                 .as("only access members that " + predicate.getDescription());
     }

archunit/src/test/java/com/tngtech/archunit/base/DescribedPredicateTest.java

@@ -1,5 +1,7 @@
 package com.tngtech.archunit.base;
 
+import java.util.Collections;
+
 import com.google.common.collect.ImmutableList;
 import com.tngtech.java.junit.dataprovider.DataProvider;
 import com.tngtech.java.junit.dataprovider.DataProviderRunner;
@@ -14,6 +16,7 @@
 import static com.tngtech.archunit.base.DescribedPredicate.describe;
 import static com.tngtech.archunit.base.DescribedPredicate.doNot;
 import static com.tngtech.archunit.base.DescribedPredicate.doesNot;
+import static com.tngtech.archunit.base.DescribedPredicate.empty;
 import static com.tngtech.archunit.base.DescribedPredicate.equalTo;
 import static com.tngtech.archunit.base.DescribedPredicate.greaterThan;
 import static com.tngtech.archunit.base.DescribedPredicate.greaterThanOrEqualTo;
@@ -181,6 +184,16 @@ public void onResultOf_works() {
         assertThat(equalTo(5).onResultOf(constant(6))).rejects(new Object());
     }
 
+    @Test
+    public void empty_works() {
+        assertThat(empty())
+                .hasDescription("empty")
+                .accepts(Collections.emptyList())
+                .accepts(Collections.emptySet())
+                .rejects(ImmutableList.of(1))
+                .rejects(Collections.singleton(""));
+    }
+
     @Test
     public void anyElementThat_works() {
         assertThat(anyElementThat(equalTo(5)))
@@ -230,4 +243,4 @@ public String toString() {
     enum Foo {
         FIRST, SECOND, THIRD
     }
-}
+}

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

@@ -32,6 +32,7 @@
 import com.tngtech.archunit.lang.conditions.ArchConditions;
 import com.tngtech.archunit.lang.syntax.elements.testclasses.SomeClass;
 import com.tngtech.archunit.lang.syntax.elements.testclasses.WrongNamedClass;
+import com.tngtech.archunit.testutil.ArchConfigurationRule;
 import com.tngtech.java.junit.dataprovider.DataProvider;
 import com.tngtech.java.junit.dataprovider.DataProviderRunner;
 import com.tngtech.java.junit.dataprovider.UseDataProvider;
@@ -45,6 +46,7 @@
 import static com.tngtech.archunit.base.DescribedPredicate.greaterThanOrEqualTo;
 import static com.tngtech.archunit.base.DescribedPredicate.lessThan;
 import static com.tngtech.archunit.base.DescribedPredicate.lessThanOrEqualTo;
+import static com.tngtech.archunit.base.DescribedPredicate.not;
 import static com.tngtech.archunit.core.domain.JavaClass.Predicates.type;
 import static com.tngtech.archunit.core.domain.JavaClassTest.expectInvalidSyntaxUsageForClassInsteadOfInterface;
 import static com.tngtech.archunit.core.domain.JavaConstructor.CONSTRUCTOR_NAME;
@@ -69,11 +71,11 @@
 import static com.tngtech.archunit.lang.conditions.ArchConditions.notHaveModifier;
 import static com.tngtech.archunit.lang.conditions.ArchPredicates.are;
 import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.classes;
+import static com.tngtech.archunit.testutil.Assertions.assertThat;
 import static com.tngtech.java.junit.dataprovider.DataProviders.$;
 import static com.tngtech.java.junit.dataprovider.DataProviders.$$;
 import static com.tngtech.java.junit.dataprovider.DataProviders.testForEach;
 import static java.util.regex.Pattern.quote;
-import static org.assertj.core.api.Assertions.assertThat;
 
 @RunWith(DataProviderRunner.class)
 public class ClassesShouldTest {
@@ -82,6 +84,9 @@ public class ClassesShouldTest {
     @Rule
     public final ExpectedException thrown = ExpectedException.none();
 
+    @Rule
+    public final ArchConfigurationRule configurationRule = new ArchConfigurationRule();
+
     @DataProvider
     public static Object[][] haveFullyQualifiedName_rules() {
         return $$(
@@ -1693,6 +1698,29 @@ public void notBeClass(ArchRule rule, Class<?> satisfied, Class<?> violated) {
                 .doesNotMatch(String.format(".*%s.* is .*", quote(satisfied.getName())));
     }
 
+    @DataProvider
+    public static Object[][] onlyAccessRules_rules() {
+        return $$(
+                $(classes().should().onlyCallMethodsThat(are(not(declaredIn(ClassWithMethod.class)))), ClassCallingMethod.class),
+                $(classes().should(ArchConditions.onlyCallMethodsThat(are(not(declaredIn(ClassWithMethod.class))))), ClassCallingMethod.class),
+                $(classes().should().onlyCallConstructorsThat(are(not(declaredIn(ClassWithConstructor.class)))), ClassCallingConstructor.class),
+                $(classes().should(ArchConditions.onlyCallConstructorsThat(are(not(declaredIn(ClassWithConstructor.class))))), ClassCallingConstructor.class),
+                $(classes().should().onlyCallCodeUnitsThat(are(not(declaredIn(ClassWithMethod.class)))), ClassCallingMethod.class),
+                $(classes().should(ArchConditions.onlyCallCodeUnitsThat(are(not(declaredIn(ClassWithMethod.class))))), ClassCallingMethod.class),
+                $(classes().should().onlyAccessFieldsThat(are(not(declaredIn(ClassWithField.class)))), ClassAccessingField.class),
+                $(classes().should(ArchConditions.onlyAccessFieldsThat(are(not(declaredIn(ClassWithField.class))))), ClassAccessingField.class),
+                $(classes().should().onlyAccessMembersThat(are(not(declaredIn(ClassWithField.class)))), ClassAccessingField.class),
+                $(classes().should(ArchConditions.onlyAccessMembersThat(are(not(declaredIn(ClassWithField.class))))), ClassAccessingField.class));
+    }
+
+    @Test
+    @UseDataProvider("onlyAccessRules_rules")
+    public void onlyCall_should_report_success_if_targets_are_non_resolvable(ArchRule rule, Class<?> classCallingUnresolvableTarget) {
+        ArchConfiguration.get().setResolveMissingDependenciesFromClassPath(false);
+
+        assertThat(rule).checking(importClasses(classCallingUnresolvableTarget)).hasNoViolation();
+    }
+
     static String locationPattern(Class<?> clazz) {
         return String.format("\\(%s.java:0\\)", quote(clazz.getSimpleName()));
     }

archunit/src/test/resources/archunit.properties

@@ -1,2 +1 @@
-resolveMissingDependenciesFromClassPath=true
-enableMd5InClassSources=true
+enableMd5InClassSources=true