Add additional tests

* Parse problem with switch fallthrough
* Verify type of switch expression

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ASTSwitchExpression.java

@@ -7,7 +7,7 @@
 
 package net.sourceforge.pmd.lang.java.ast;
 
-public class ASTSwitchExpression extends AbstractJavaNode {
+public class ASTSwitchExpression extends AbstractJavaTypeNode {
     ASTSwitchExpression(int id) {
         super(id);
     }

pmd-java/src/test/java/net/sourceforge/pmd/lang/java/ast/Java12Test.java

@@ -85,6 +85,8 @@ public class Java12Test {
         Assert.assertEquals(6, switchExpression.jjtGetNumChildren());
         Assert.assertTrue(switchExpression.jjtGetChild(0) instanceof ASTExpression);
         Assert.assertEquals(5, switchExpression.findChildrenOfType(ASTSwitchLabeledRule.class).size());
+
+        Assert.assertEquals(Integer.TYPE, switchExpression.getType());
     }
 
 }

pmd-java/src/test/java/net/sourceforge/pmd/lang/java/ast/ParserCornersTest.java

@@ -274,6 +274,14 @@ public class ParserCornersTest {
         Assert.assertTrue("Test setup wrong - variable 'someVarNameSameAsMethodReference' not found anymore!", foundVariable);
     }
 
+    @Test
+    public void testSwitchWithFallthrough() throws Exception {
+        ASTCompilationUnit compilationUnit = ParserTstUtil.parseAndTypeResolveJava("11", readAsString("SwitchWithFallthrough.java"));
+        Assert.assertNotNull(compilationUnit);
+        ASTSwitchStatement switchStatement = compilationUnit.getFirstDescendantOfType(ASTSwitchStatement.class);
+        Assert.assertEquals(2, switchStatement.findChildrenOfType(ASTSwitchLabel.class).size());
+    }
+
     private String readAsString(String resource) {
         try (InputStream in = ParserCornersTest.class.getResourceAsStream(resource)) {
             return IOUtils.toString(in, StandardCharsets.UTF_8);

pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/ast/SwitchWithFallthrough.java

@@ -0,0 +1,11 @@
+public class SwitchWithFallthrough {
+
+    // only fall through, no block statements.
+    public void myMethod() {
+        int a = 1;
+        switch (a) {
+            case 1:
+            default:
+        }
+    }
+}