Refactoring in the unit test utility framework:
* Moved unit test utilities to the onlab-junit package under utils/junit
- ImmutableClassChecker
- TestUtils and TestUtilsTest
* Added/ported unit test utilities from the older code
- UtilityClassChecker and UtilityClassCheckerTest
- ImmutableClassCheckerTest
* Updated/fixed some of the pom.xml files in the context of the
onlab-junit package:
- Added <scope>test</scope>
- Replaced hard-coded "1.0.0-SNAPSHOT" with "${project.version}"
Change-Id: Ie5f51ba401ca1748340f38848ab6bfc251964adc
diff --git a/utils/junit/src/main/java/org/onlab/junit/ImmutableClassChecker.java b/utils/junit/src/main/java/org/onlab/junit/ImmutableClassChecker.java
new file mode 100644
index 0000000..30d895e
--- /dev/null
+++ b/utils/junit/src/main/java/org/onlab/junit/ImmutableClassChecker.java
@@ -0,0 +1,124 @@
+package org.onlab.junit;
+
+import org.hamcrest.Description;
+import org.hamcrest.StringDescription;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+
+/**
+ * Hamcrest style class for verifying that a class follows the
+ * accepted rules for immutable classes.
+ *
+ * The rules that are enforced for immutable classes:
+ * - the class must be declared final
+ * - all data members of the class must be declared private and final
+ * - the class must not define any setter methods
+ */
+
+public class ImmutableClassChecker {
+
+ private String failureReason = "";
+
+ /**
+ * Method to determine if a given class is a properly specified
+ * immutable class.
+ *
+ * @param clazz the class to check
+ * @return true if the given class is a properly specified immutable class.
+ */
+ private boolean isImmutableClass(Class<?> clazz) {
+ // class must be declared final
+ if (!Modifier.isFinal(clazz.getModifiers())) {
+ failureReason = "a class that is not final";
+ return false;
+ }
+
+ // class must have only final and private data members
+ for (final Field field : clazz.getDeclaredFields()) {
+ if (field.getName().startsWith("__cobertura")) {
+ // cobertura sticks these fields into classes - ignore them
+ continue;
+ }
+ if (!Modifier.isFinal(field.getModifiers())) {
+ failureReason = "a field named '" + field.getName() +
+ "' that is not final";
+ return false;
+ }
+ if (!Modifier.isPrivate(field.getModifiers())) {
+ //
+ // NOTE: We relax the recommended rules for defining immutable
+ // objects and allow "static final" fields that are not
+ // private. The "final" check was already done above so we
+ // don't repeat it here.
+ //
+ if (!Modifier.isStatic(field.getModifiers())) {
+ failureReason = "a field named '" + field.getName() +
+ "' that is not private and is not static";
+ return false;
+ }
+ }
+ }
+
+ // class must not define any setters
+ for (final Method method : clazz.getMethods()) {
+ if (method.getDeclaringClass().equals(clazz)) {
+ if (method.getName().startsWith("set")) {
+ failureReason = "a class with a setter named '" + method.getName() + "'";
+ return false;
+ }
+ }
+ }
+
+ return true;
+ }
+
+ /**
+ * Describe why an error was reported. Uses Hamcrest style Description
+ * interfaces.
+ *
+ * @param description the Description object to use for reporting the
+ * mismatch
+ */
+ public void describeMismatch(Description description) {
+ description.appendText(failureReason);
+ }
+
+ /**
+ * Describe the source object that caused an error, using a Hamcrest
+ * Matcher style interface. In this case, it always returns
+ * that we are looking for a properly defined utility class.
+ *
+ * @param description the Description object to use to report the "to"
+ * object
+ */
+ public void describeTo(Description description) {
+ description.appendText("a properly defined immutable class");
+ }
+
+ /**
+ * Assert that the given class adheres to the utility class rules.
+ *
+ * @param clazz the class to check
+ *
+ * @throws java.lang.AssertionError if the class is not a valid
+ * utility class
+ */
+ public static void assertThatClassIsImmutable(Class<?> clazz) {
+ final ImmutableClassChecker checker = new ImmutableClassChecker();
+ if (!checker.isImmutableClass(clazz)) {
+ final Description toDescription = new StringDescription();
+ final Description mismatchDescription = new StringDescription();
+
+ checker.describeTo(toDescription);
+ checker.describeMismatch(mismatchDescription);
+ final String reason =
+ "\n" +
+ "Expected: is \"" + toDescription.toString() + "\"\n" +
+ " but : was \"" + mismatchDescription.toString() + "\"";
+
+ throw new AssertionError(reason);
+ }
+ }
+}