Extended the syntax to offer an ArchRuleDefinition.theClass(..) and

noClass(..) entry point to create rules based on a specific class. Also
added should().be(..) and should().notBe().

Issue: TNG#60
Signed-off-by: Michael Sherman <msherman32@gatech.edu>

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

@@ -65,7 +65,6 @@
 import static com.tngtech.archunit.core.domain.properties.HasName.Predicates.nameMatching;
 import static com.tngtech.archunit.core.domain.properties.HasOwner.Predicates.With.owner;
 import static com.tngtech.archunit.core.domain.properties.HasParameterTypes.Predicates.parameterTypes;
-import static com.tngtech.archunit.lang.conditions.ArchPredicates.be;
 import static com.tngtech.archunit.lang.conditions.ArchPredicates.have;
 import static java.util.Arrays.asList;
 
@@ -276,6 +275,33 @@ private static DescribedPredicate<? super JavaFieldAccess> ownerAndNameAre(Strin
                 .as(ownerName + "." + fieldName);
     }
 
+    public static ArchCondition<JavaClass> be(final Class<?> clazz) {
+        return be(clazz.getName());
+    }
+
+    public static ArchCondition<JavaClass> notBe(final Class<?> clazz) {
+        return not(be(clazz));
+    }
+
+    public static ArchCondition<JavaClass> be(final String className) {
+        return new ArchCondition<JavaClass>("be " + className) {
+            @Override
+            public void check(JavaClass javaClass, ConditionEvents events) {
+                boolean itemEquivalentToClazz = javaClass.getName().equals(className);
+                String message = String.format("class %s %s %s in %s",
+                        javaClass.getName(),
+                        itemEquivalentToClazz ? "is" : "is not",
+                        className,
+                        formatLocation(javaClass, 0));
+                events.add(new SimpleConditionEvent(javaClass, itemEquivalentToClazz, message));
+            }
+        };
+    }
+
+    public static ArchCondition<JavaClass> notBe(final String className) {
+        return not(be(className));
+    }
+
     @PublicAPI(usage = ACCESS)
     public static ArchCondition<JavaClass> haveFullyQualifiedName(final String name) {
         final DescribedPredicate<HasName> haveFullyQualifiedName = have(fullyQualifiedName(name));
@@ -442,7 +468,7 @@ private static ArchCondition<JavaClass> residesConditionForPredicate(final Descr
             @Override
             public void check(JavaClass item, ConditionEvents events) {
                 boolean satisfied = resideInAPackage.apply(item);
-                String message = String.format("Class %s %s %s in %s",
+                String message = String.format("class %s %s %s in %s",
                         item.getName(),
                         satisfied ? "does" : "doesn't",
                         resideInAPackage.getDescription(),
@@ -578,7 +604,7 @@ public static ArchCondition<JavaClass> notBeMetaAnnotatedWith(DescribedPredicate
     }
 
     private static ArchCondition<JavaClass> createAnnotatedCondition(final DescribedPredicate<CanBeAnnotated> annotatedWith) {
-        return new ArchCondition<JavaClass>(be(annotatedWith).getDescription()) {
+        return new ArchCondition<JavaClass>(ArchPredicates.be(annotatedWith).getDescription()) {
             @Override
             public void check(JavaClass item, ConditionEvents events) {
                 boolean satisfied = annotatedWith.apply(item);
@@ -720,7 +746,7 @@ public static ArchCondition<JavaClass> notBeInterfaces() {
     }
 
     private static ArchCondition<JavaClass> createAssignableCondition(final DescribedPredicate<JavaClass> assignable) {
-        return new ArchCondition<JavaClass>(be(assignable).getDescription()) {
+        return new ArchCondition<JavaClass>(ArchPredicates.be(assignable).getDescription()) {
             @Override
             public void check(JavaClass item, ConditionEvents events) {
                 boolean satisfied = assignable.apply(item);

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

@@ -17,19 +17,23 @@
 
 import com.tngtech.archunit.PublicAPI;
 import com.tngtech.archunit.base.Function;
+import com.tngtech.archunit.base.Function.Functions;
 import com.tngtech.archunit.core.domain.JavaClass;
 import com.tngtech.archunit.core.domain.JavaClasses;
 import com.tngtech.archunit.core.importer.ClassFileImporter;
+import com.tngtech.archunit.lang.AbstractClassesTransformer;
 import com.tngtech.archunit.lang.ArchCondition;
 import com.tngtech.archunit.lang.ArchRule;
 import com.tngtech.archunit.lang.ClassesTransformer;
 import com.tngtech.archunit.lang.Priority;
+import com.tngtech.archunit.lang.syntax.elements.GivenClass;
 import com.tngtech.archunit.lang.syntax.elements.GivenClasses;
 import com.tngtech.archunit.lang.syntax.elements.GivenObjects;
 
 import static com.tngtech.archunit.PublicAPI.Usage.ACCESS;
 import static com.tngtech.archunit.lang.Priority.MEDIUM;
 import static com.tngtech.archunit.lang.conditions.ArchConditions.never;
+import static java.util.Collections.singleton;
 
 public final class ArchRuleDefinition {
     private ArchRuleDefinition() {
@@ -66,6 +70,22 @@ public static GivenClasses noClasses() {
         return priority(MEDIUM).noClasses();
     }
 
+    public static GivenClass theClass(Class<?> clazz) {
+        return priority(MEDIUM).theClass(clazz);
+    }
+
+    public static GivenClass theClass(String className) {
+        return priority(MEDIUM).theClass(className);
+    }
+
+    public static GivenClass noClass(Class<?> clazz) {
+        return priority(MEDIUM).noClass(clazz);
+    }
+
+    public static GivenClass noClass(String className) {
+        return priority(MEDIUM).noClass(className);
+    }
+
     public static final class Creator {
         private final Priority priority;
 
@@ -110,6 +130,37 @@ public <TYPE> GivenObjects<TYPE> no(ClassesTransformer<TYPE> classesTransformer)
                     classesTransformer.as("no " + classesTransformer.getDescription()),
                     ArchRuleDefinition.<TYPE>negateCondition());
         }
+
+        @PublicAPI(usage = ACCESS)
+        public GivenClass theClass(final Class<?> clazz) {
+            return theClass(clazz.getName());
+        }
+
+        @PublicAPI(usage = ACCESS)
+        public GivenClass theClass(final String className) {
+            ClassesTransformer<JavaClass> theClass = theClassTransformer(className);
+            return new GivenClassInternal(priority, theClass, Functions.<ArchCondition<JavaClass>>identity());
+        }
+
+        @PublicAPI(usage = ACCESS)
+        public GivenClass noClass(final Class<?> clazz) {
+            return noClass(clazz.getName());
+        }
+
+        @PublicAPI(usage = ACCESS)
+        public GivenClass noClass(final String className) {
+            ClassesTransformer<JavaClass> noClass = theClassTransformer(className).as("no class " + className);
+            return new GivenClassInternal(priority, noClass, ArchRuleDefinition.<JavaClass>negateCondition());
+        }
+
+        private ClassesTransformer<JavaClass> theClassTransformer(final String className) {
+            return new AbstractClassesTransformer<JavaClass>("the class " + className) {
+                @Override
+                public Iterable<JavaClass> doTransform(JavaClasses classes) {
+                    return singleton(classes.get(className));
+                }
+            };
+        }
     }
 
     private static <T> Function<ArchCondition<T>, ArchCondition<T>> negateCondition() {

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

@@ -59,6 +59,23 @@ private ClassesShouldInternal(ClassesTransformer<JavaClass> classesTransformer,
         super(classesTransformer, priority, conditionAggregator, prepareCondition);
     }
 
+    public ClassesShouldConjunction be(final Class<?> clazz) {
+        return copyWithNewCondition(conditionAggregator.add(ArchConditions.be(clazz)));
+    }
+
+    public ClassesShouldConjunction notBe(final Class<?> clazz) {
+        return copyWithNewCondition(conditionAggregator.add(ArchConditions.notBe(clazz)));
+    }
+
+    @Override
+    public ClassesShouldConjunction be(String className) {
+        return copyWithNewCondition(conditionAggregator.add(ArchConditions.be(className)));
+    }
+
+    public ClassesShouldConjunction notBe(String className) {
+        return copyWithNewCondition(conditionAggregator.add(ArchConditions.notBe(className)));
+    }
+
     @Override
     public ClassesShouldConjunction haveFullyQualifiedName(final String name) {
         return copyWithNewCondition(conditionAggregator.add(ArchConditions.haveFullyQualifiedName(name)));

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

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2018 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.lang.syntax;
+
+import com.tngtech.archunit.base.Function;
+import com.tngtech.archunit.core.domain.JavaClass;
+import com.tngtech.archunit.lang.ArchCondition;
+import com.tngtech.archunit.lang.ClassesTransformer;
+import com.tngtech.archunit.lang.Priority;
+import com.tngtech.archunit.lang.syntax.elements.ClassesShould;
+import com.tngtech.archunit.lang.syntax.elements.ClassesShouldConjunction;
+import com.tngtech.archunit.lang.syntax.elements.GivenClass;
+
+class GivenClassInternal implements GivenClass {
+    private final Priority priority;
+    private final ClassesTransformer<JavaClass> classesTransformer;
+    private final Function<ArchCondition<JavaClass>, ArchCondition<JavaClass>> prepareCondition;
+
+    GivenClassInternal(Priority priority, ClassesTransformer<JavaClass> classesTransformer,
+            Function<ArchCondition<JavaClass>, ArchCondition<JavaClass>> prepareCondition) {
+        this.priority = priority;
+        this.classesTransformer = classesTransformer;
+        this.prepareCondition = prepareCondition;
+    }
+
+    @Override
+    public ClassesShould should() {
+        return new ClassesShouldInternal(classesTransformer, priority, prepareCondition);
+    }
+
+    @Override
+    public ClassesShouldConjunction should(ArchCondition<JavaClass> condition) {
+        return new ClassesShouldInternal(classesTransformer, priority, condition, prepareCondition);
+    }
+}

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

@@ -802,4 +802,38 @@ public interface ClassesShould {
      */
     @PublicAPI(usage = ACCESS)
     ClassesShouldConjunction notBeInterfaces();
+
+    /**
+     * Asserts that the rule matches exactly the given class.
+     *
+     * @param clazz the only class the should be matched
+     * @return A syntax element that can either be used as working rule, or to continue specifying a more complex rule
+     */
+    @PublicAPI(usage = ACCESS)
+    ClassesShouldConjunction be(Class<?> clazz);
+
+    /**
+     * Asserts that the rule does not match the given class.
+     *
+     * @param clazz the class that should not be matched
+     * @return A syntax element that can either be used as working rule, or to continue specifying a more complex rule
+     */
+    @PublicAPI(usage = ACCESS)
+    ClassesShouldConjunction notBe(Class<?> clazz);
+
+    /**
+     * Asserts that the rule matches exactly the class with the given fully qualified class name.
+     *
+     * @param className the name of the only class that should be matched.
+     * @return A syntax element that can either be used as working rule, or to continue specifying a more complex rule
+     */
+    ClassesShouldConjunction be(String className);
+
+    /**
+     * Asserts that the rule does not match the class with the given fully qualified class name.
+     *
+     * @param className the name of the class that should not be matched.
+     * @return A syntax element that can either be used as working rule, or to continue specifying a more complex rule
+     */
+    ClassesShouldConjunction notBe(String className);
 }

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

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2018 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.lang.syntax.elements;
+
+import com.tngtech.archunit.core.domain.JavaClass;
+import com.tngtech.archunit.lang.ArchCondition;
+
+public interface GivenClass {
+    ClassesShould should();
+
+    ClassesShouldConjunction should(ArchCondition<JavaClass> condition);
+}