Add a checker class for Immutable classes
Added a class to use in Unit tests to make sure that
classes are immutable. It checks for the following conditions:
- The class must be declared final
- All data members must be declared private and final
- There must be no setter methods
(defined as a method name starting with "set")
Also added a unit test that tests the operation of the checker
Change-Id: I5d0f7a0b84d574938a750ab31cfc7c9677aa59e3
diff --git a/src/test/java/net/onrc/onos/core/util/ImmutableClassCheckerTest.java b/src/test/java/net/onrc/onos/core/util/ImmutableClassCheckerTest.java
new file mode 100644
index 0000000..151c802
--- /dev/null
+++ b/src/test/java/net/onrc/onos/core/util/ImmutableClassCheckerTest.java
@@ -0,0 +1,119 @@
+package net.onrc.onos.core.util;
+
+import org.junit.Test;
+
+import static net.onrc.onos.core.util.ImmutableClassChecker.assertThatClassIsImmutable;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+
+/**
+ * Set of unit tests to check the implementation of the immutable class
+ * checker.
+ */
+public class ImmutableClassCheckerTest {
+ /**
+ * Test class for non final class check.
+ */
+ static class NonFinal {
+ private NonFinal() {}
+ }
+
+ /**
+ * Check that a non final class correctly produces an error.
+ * @throws Exception if any of the reflection lookups fail.
+ */
+ @Test
+ public void testNonFinalClass() throws Exception {
+ boolean gotException = false;
+ try {
+ assertThatClassIsImmutable(NonFinal.class);
+ } catch (AssertionError assertion) {
+ assertThat(assertion.getMessage(),
+ containsString("is not final"));
+ gotException = true;
+ }
+ assertThat(gotException, is(true));
+ }
+
+ /**
+ * Test class for non private member class check.
+ */
+ static final class FinalProtectedMember {
+ protected final int x = 0;
+ }
+
+ /**
+ * Check that a final class with a non-private member is properly detected.
+ *
+ * @throws Exception if any of the reflection lookups fail.
+ */
+ @Test
+ public void testFinalProtectedMember() throws Exception {
+ boolean gotException = false;
+ try {
+ assertThatClassIsImmutable(FinalProtectedMember.class);
+ } catch (AssertionError assertion) {
+ assertThat(assertion.getMessage(),
+ containsString("a field named 'x' that is not private"));
+ gotException = true;
+ }
+ assertThat(gotException, is(true));
+ }
+
+ /**
+ * Test class for non private member class check.
+ */
+ static final class NotFinalPrivateMember {
+ private int x = 0;
+ }
+
+ /**
+ * Check that a final class with a non-final private
+ * member is properly detected.
+ *
+ * @throws Exception if any of the reflection lookups fail.
+ */
+ @Test
+ public void testNotFinalPrivateMember() throws Exception {
+ boolean gotException = false;
+ try {
+ assertThatClassIsImmutable(NotFinalPrivateMember.class);
+ } catch (AssertionError assertion) {
+ assertThat(assertion.getMessage(),
+ containsString("a field named 'x' that is not final"));
+ gotException = true;
+ }
+ assertThat(gotException, is(true));
+ }
+
+ /**
+ * Test class for non private member class check.
+ */
+ static final class ClassWithSetter {
+ private final int x = 0;
+ public void setX(int newX) {
+ }
+ }
+
+ /**
+ * Check that a final class with a final private
+ * member that is modifyable by a setter is properly detected.
+ *
+ * @throws Exception if any of the reflection lookups fail.
+ */
+ @Test
+ public void testClassWithSetter() throws Exception {
+ boolean gotException = false;
+ try {
+ assertThatClassIsImmutable(ClassWithSetter.class);
+ } catch (AssertionError assertion) {
+ assertThat(assertion.getMessage(),
+ containsString("a class with a setter named 'setX'"));
+ gotException = true;
+ }
+ assertThat(gotException, is(true));
+ }
+
+}
+