Add referenced class objects to JavaClass #518

So far ArchUnit has not been able to detect the pure usage of class objects as dependencies. E.g. the following example would not have detected a dependency on `Evil`, since besides the reference to the class object no further dependency on `Evil` (like a field access or method call) has occurred.

```
class Example {
  final Map<Class<?>, Object> association = Map.of(Evil.class, anything);
}
```

With this PR `JavaClass` now knows its `referencedClassObjects`, including the respective line number. Furthermore class objects are now parts of the `dependencies{From/To}Self` of a `JavaClass`.

Resolves: #309 
Issue: #446 
Resolves: #474 
Resolves: #515

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

@@ -972,6 +972,9 @@ Stream<DynamicTest> OnionArchitectureTest() {
                                 .by(field(ShoppingService.class, "productRepository").ofType(ProductRepository.class))
                                 .by(field(ShoppingService.class, "shoppingCartRepository").ofType(ShoppingCartRepository.class))
 
+                                .by(method(AdministrationCLI.class, "handle")
+                                        .referencingClassObject(ProductRepository.class)
+                                        .inLine(16))
                                 .by(callFromMethod(AdministrationCLI.class, "handle", String[].class, AdministrationPort.class)
                                         .toMethod(ProductRepository.class, "getTotalCount")
                                         .inLine(17).asDependency())

archunit-integration-test/src/test/java/com/tngtech/archunit/testutils/ExpectedDependency.java

@@ -190,7 +190,11 @@ public ExpectedDependency withAnnotationType(Class<?> annotationType) {
         }
 
         public AddsLineNumber checkingInstanceOf(Class<?> target) {
-            return new AddsLineNumber(owner, getOriginName(), target);
+            return new AddsLineNumber(owner, getOriginName(), "checks instanceof", target);
+        }
+
+        public AddsLineNumber referencingClassObject(Class<?> target) {
+            return new AddsLineNumber(owner, getOriginName(), "references class object", target);
         }
 
         private String getOriginName() {
@@ -201,15 +205,17 @@ public static class AddsLineNumber {
             private final Class<?> owner;
             private final String origin;
             private final Class<?> target;
+            private final String dependencyType;
 
-            private AddsLineNumber(Class<?> owner, String origin, Class<?> target) {
+            private AddsLineNumber(Class<?> owner, String origin, String dependencyType, Class<?> target) {
                 this.owner = owner;
                 this.origin = origin;
                 this.target = target;
+                this.dependencyType = dependencyType;
             }
 
             public ExpectedDependency inLine(int lineNumber) {
-                String dependencyPattern = getDependencyPattern(origin, "checks instanceof", target.getName(), lineNumber);
+                String dependencyPattern = getDependencyPattern(origin, dependencyType, target.getName(), lineNumber);
                 return new ExpectedDependency(owner, target, dependencyPattern);
             }
         }

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

@@ -28,6 +28,7 @@
 import com.tngtech.archunit.base.HasDescription;
 import com.tngtech.archunit.base.Optional;
 import com.tngtech.archunit.core.domain.properties.HasName;
+import com.tngtech.archunit.core.domain.properties.HasOwner;
 import com.tngtech.archunit.core.domain.properties.HasSourceCodeLocation;
 
 import static com.google.common.base.Preconditions.checkArgument;
@@ -100,44 +101,52 @@ static Dependency fromInheritance(JavaClass origin, JavaClass targetSupertype) {
     }
 
     static Set<Dependency> tryCreateFromField(JavaField field) {
-        return tryCreateDependencyFromJavaMember(field, "has type", field.getRawType());
+        return tryCreateDependency(field, "has type", field.getRawType());
     }
 
     static Set<Dependency> tryCreateFromReturnType(JavaMethod method) {
-        return tryCreateDependencyFromJavaMember(method, "has return type", method.getRawReturnType());
+        return tryCreateDependency(method, "has return type", method.getRawReturnType());
     }
 
     static Set<Dependency> tryCreateFromParameter(JavaCodeUnit codeUnit, JavaClass parameter) {
-        return tryCreateDependencyFromJavaMember(codeUnit, "has parameter of type", parameter);
+        return tryCreateDependency(codeUnit, "has parameter of type", parameter);
     }
 
     static Set<Dependency> tryCreateFromThrowsDeclaration(ThrowsDeclaration<? extends JavaCodeUnit> declaration) {
-        return tryCreateDependencyFromJavaMember(declaration.getLocation(), "throws type", declaration.getRawType());
+        return tryCreateDependency(declaration.getLocation(), "throws type", declaration.getRawType());
     }
 
     static Set<Dependency> tryCreateFromInstanceofCheck(InstanceofCheck instanceofCheck) {
-        return tryCreateDependencyFromJavaMemberWithLocation(instanceofCheck.getOwner(), "checks instanceof", instanceofCheck.getRawType(), instanceofCheck.getLineNumber());
+        return tryCreateDependency(
+                instanceofCheck.getOwner(), "checks instanceof",
+                instanceofCheck.getRawType(), instanceofCheck.getSourceCodeLocation());
+    }
+
+    static Set<Dependency> tryCreateFromReferencedClassObject(ReferencedClassObject referencedClassObject) {
+        return tryCreateDependency(
+                referencedClassObject.getOwner(), "references class object",
+                referencedClassObject.getRawType(), referencedClassObject.getSourceCodeLocation());
     }
 
     static Set<Dependency> tryCreateFromAnnotation(JavaAnnotation<?> target) {
         Origin origin = findSuitableOrigin(target, target.getAnnotatedElement());
-        return tryCreateDependency(origin.originClass, origin.originDescription, "is annotated with", target.getRawType());
+        return tryCreateDependency(origin, "is annotated with", target.getRawType());
     }
 
     static Set<Dependency> tryCreateFromAnnotationMember(JavaAnnotation<?> annotation, JavaClass memberType) {
         Origin origin = findSuitableOrigin(annotation, annotation.getAnnotatedElement());
-        return tryCreateDependency(origin.originClass, origin.originDescription, "has annotation member of type", memberType);
+        return tryCreateDependency(origin, "has annotation member of type", memberType);
     }
 
     static Set<Dependency> tryCreateFromTypeParameter(JavaTypeVariable<?> typeParameter, JavaClass typeParameterDependency) {
         String dependencyType = "has type parameter '" + typeParameter.getName() + "' depending on";
         Origin origin = findSuitableOrigin(typeParameter, typeParameter.getOwner());
-        return tryCreateDependency(origin.originClass, origin.originDescription, dependencyType, typeParameterDependency);
+        return tryCreateDependency(origin, dependencyType, typeParameterDependency);
     }
 
     static Set<Dependency> tryCreateFromGenericSuperclassTypeArguments(JavaClass originClass, JavaType superclass, JavaClass typeArgumentDependency) {
         String dependencyType = "has generic superclass " + bracketFormat(superclass.getName()) + " with type argument depending on";
-        return tryCreateDependency(originClass, originClass.getDescription(), dependencyType, typeArgumentDependency);
+        return tryCreateDependency(originClass, originClass.getDescription(), dependencyType, typeArgumentDependency, originClass.getSourceCodeLocation());
     }
 
     private static Origin findSuitableOrigin(Object dependencyCause, Object originCandidate) {
@@ -152,22 +161,20 @@ private static Origin findSuitableOrigin(Object dependencyCause, Object originCa
         throw new IllegalStateException("Could not find suitable dependency origin for " + dependencyCause);
     }
 
-    private static Set<Dependency> tryCreateDependencyFromJavaMember(JavaMember origin, String dependencyType, JavaClass target) {
-        return tryCreateDependency(origin.getOwner(), origin.getDescription(), dependencyType, target);
-    }
-
-    private static Set<Dependency> tryCreateDependencyFromJavaMemberWithLocation(JavaMember origin, String dependencyType, JavaClass target, int lineNumber) {
-        return tryCreateDependency(origin.getOwner(), origin.getDescription(), dependencyType, target, SourceCodeLocation.of(origin.getOwner(), lineNumber));
+    private static <T extends HasOwner<JavaClass> & HasDescription> Set<Dependency> tryCreateDependency(
+            T origin, String dependencyType, JavaClass targetClass) {
+        return tryCreateDependency(origin, dependencyType, targetClass, origin.getOwner().getSourceCodeLocation());
     }
 
-    private static Set<Dependency> tryCreateDependency(
-            JavaClass originClass, String originDescription, String dependencyType, JavaClass targetClass) {
+    private static <T extends HasOwner<JavaClass> & HasDescription> Set<Dependency> tryCreateDependency(
+            T origin, String dependencyType, JavaClass targetClass, SourceCodeLocation sourceCodeLocation) {
 
-        return tryCreateDependency(originClass, originDescription, dependencyType, targetClass, originClass.getSourceCodeLocation());
+        return tryCreateDependency(origin.getOwner(), origin.getDescription(), dependencyType, targetClass, sourceCodeLocation);
     }
 
     private static Set<Dependency> tryCreateDependency(
             JavaClass originClass, String originDescription, String dependencyType, JavaClass targetClass, SourceCodeLocation sourceCodeLocation) {
+
         ImmutableSet.Builder<Dependency> dependencies = ImmutableSet.<Dependency>builder()
                 .addAll(createComponentTypeDependencies(originClass, originDescription, targetClass, sourceCodeLocation));
         String targetDescription = bracketFormat(targetClass.getName());
@@ -177,7 +184,9 @@ private static Set<Dependency> tryCreateDependency(
         return dependencies.build();
     }
 
-    private static Set<Dependency> createComponentTypeDependencies(JavaClass originClass, String originDescription, JavaClass targetClass, SourceCodeLocation sourceCodeLocation) {
+    private static Set<Dependency> createComponentTypeDependencies(
+            JavaClass originClass, String originDescription, JavaClass targetClass, SourceCodeLocation sourceCodeLocation) {
+
         ImmutableSet.Builder<Dependency> result = ImmutableSet.builder();
         Optional<JavaClass> componentType = targetClass.tryGetComponentType();
         while (componentType.isPresent()) {
@@ -271,14 +280,24 @@ public static JavaClasses toTargetClasses(Iterable<Dependency> dependencies) {
         return JavaClasses.of(classes);
     }
 
-    private static class Origin {
+    private static class Origin implements HasOwner<JavaClass>, HasDescription {
         private final JavaClass originClass;
         private final String originDescription;
 
         private Origin(JavaClass originClass, String originDescription) {
             this.originClass = originClass;
             this.originDescription = originDescription;
         }
+
+        @Override
+        public JavaClass getOwner() {
+            return originClass;
+        }
+
+        @Override
+        public String getDescription() {
+            return originDescription;
+        }
     }
 
     public static final class Predicates {

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

@@ -146,6 +146,10 @@ public static Source createSource(URI uri, Optional<String> sourceFileName, bool
         return new Source(uri, sourceFileName, md5InClassSourcesEnabled);
     }
 
+    public static ReferencedClassObject createReferencedClassObject(JavaCodeUnit codeUnit, JavaClass javaClass, int lineNumber) {
+        return ReferencedClassObject.from(codeUnit, javaClass, lineNumber);
+    }
+
     public static <CODE_UNIT extends JavaCodeUnit> ThrowsClause<CODE_UNIT> createThrowsClause(CODE_UNIT codeUnit, List<JavaClass> types) {
         return ThrowsClause.from(codeUnit, types);
     }

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

@@ -17,21 +17,25 @@
 
 import com.tngtech.archunit.PublicAPI;
 import com.tngtech.archunit.core.domain.properties.HasOwner;
+import com.tngtech.archunit.core.domain.properties.HasSourceCodeLocation;
 import com.tngtech.archunit.core.domain.properties.HasType;
 
+import static com.google.common.base.MoreObjects.toStringHelper;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
 
-public final class InstanceofCheck implements HasType, HasOwner<JavaCodeUnit> {
+public final class InstanceofCheck implements HasType, HasOwner<JavaCodeUnit>, HasSourceCodeLocation {
 
     private final JavaCodeUnit owner;
     private final JavaClass target;
     private final int lineNumber;
+    private final SourceCodeLocation sourceCodeLocation;
 
     private InstanceofCheck(JavaCodeUnit owner, JavaClass target, int lineNumber) {
         this.owner = checkNotNull(owner);
         this.target = checkNotNull(target);
         this.lineNumber = lineNumber;
+        sourceCodeLocation = SourceCodeLocation.of(owner.getOwner(), lineNumber);
     }
 
     @Override
@@ -57,6 +61,20 @@ public int getLineNumber() {
         return lineNumber;
     }
 
+    @Override
+    public SourceCodeLocation getSourceCodeLocation() {
+        return sourceCodeLocation;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("owner", owner)
+                .add("target", target)
+                .add("lineNumber", lineNumber)
+                .toString();
+    }
+
     static InstanceofCheck from(JavaCodeUnit owner, JavaClass target, int lineNumber) {
         return new InstanceofCheck(owner, target, lineNumber);
     }

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

@@ -648,6 +648,15 @@ public List<JavaTypeVariable<JavaClass>> getTypeParameters() {
         return typeParameters;
     }
 
+    @PublicAPI(usage = ACCESS)
+    public Set<ReferencedClassObject> getReferencedClassObjects() {
+        ImmutableSet.Builder<ReferencedClassObject> result = ImmutableSet.builder();
+        for (JavaCodeUnit codeUnit : codeUnits) {
+            result.addAll(codeUnit.getReferencedClassObjects());
+        }
+        return result.build();
+    }
+
     @Override
     @PublicAPI(usage = ACCESS)
     public JavaClass toErasure() {

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

@@ -52,6 +52,7 @@ public Set<Dependency> get() {
                 result.addAll(constructorParameterDependenciesFromSelf());
                 result.addAll(annotationDependenciesFromSelf());
                 result.addAll(instanceofCheckDependenciesFromSelf());
+                result.addAll(referencedClassObjectDependenciesFromSelf());
                 result.addAll(typeParameterDependenciesFromSelf());
                 return result.build();
             }
@@ -158,6 +159,14 @@ private Set<Dependency> instanceofCheckDependenciesFromSelf() {
         return result.build();
     }
 
+    private Set<Dependency> referencedClassObjectDependenciesFromSelf() {
+        ImmutableSet.Builder<Dependency> result = ImmutableSet.builder();
+        for (ReferencedClassObject referencedClassObject : javaClass.getReferencedClassObjects()) {
+            result.addAll(Dependency.tryCreateFromReferencedClassObject(referencedClassObject));
+        }
+        return result.build();
+    }
+
     private Set<Dependency> typeParameterDependenciesFromSelf() {
         ImmutableSet.Builder<Dependency> result = ImmutableSet.builder();
         for (JavaTypeVariable<?> typeVariable : javaClass.getTypeParameters()) {

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

@@ -50,6 +50,7 @@ public abstract class JavaCodeUnit extends JavaMember implements HasParameterTyp
     private final JavaClass returnType;
     private final JavaClassList parameters;
     private final String fullName;
+    private final Set<ReferencedClassObject> referencedClassObjects;
     private final Set<InstanceofCheck> instanceofChecks;
 
     private Set<JavaFieldAccess> fieldAccesses = Collections.emptySet();
@@ -61,7 +62,8 @@ public abstract class JavaCodeUnit extends JavaMember implements HasParameterTyp
         this.returnType = builder.getReturnType();
         this.parameters = builder.getParameters();
         fullName = formatMethod(getOwner().getName(), getName(), getRawParameterTypes());
-        instanceofChecks = builder.getInstanceofChecks(this);
+        referencedClassObjects = ImmutableSet.copyOf(builder.getReferencedClassObjects(this));
+        instanceofChecks = ImmutableSet.copyOf(builder.getInstanceofChecks(this));
     }
 
     /**
@@ -112,6 +114,11 @@ public Set<JavaConstructorCall> getConstructorCallsFromSelf() {
         return constructorCalls;
     }
 
+    @PublicAPI(usage = ACCESS)
+    public Set<ReferencedClassObject> getReferencedClassObjects() {
+        return referencedClassObjects;
+    }
+
     @PublicAPI(usage = ACCESS)
     public Set<InstanceofCheck> getInstanceofChecks() {
         return instanceofChecks;