Add test for Java 'this' keyword typeresolution

pmd-java8/src/test/java/net/sourceforge/pmd/typeresolution/ClassTypeResolverJava8Test.java

@@ -6,7 +6,14 @@ package net.sourceforge.pmd.typeresolution;
 
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
 
+import net.sourceforge.pmd.lang.ast.Node;
+import net.sourceforge.pmd.lang.java.ast.ASTPrimaryExpression;
+import net.sourceforge.pmd.lang.java.ast.ASTPrimaryPrefix;
+import net.sourceforge.pmd.typeresolution.testdata.ThisExpression;
+import org.jaxen.JaxenException;
 import org.junit.Test;
 
 import net.sourceforge.pmd.lang.LanguageRegistry;
@@ -16,6 +23,8 @@ import net.sourceforge.pmd.lang.java.ast.ASTCompilationUnit;
 import net.sourceforge.pmd.typeresolution.testdata.UsesJavaStreams;
 import net.sourceforge.pmd.typeresolution.testdata.UsesRepeatableAnnotations;
 
+import static org.junit.Assert.assertEquals;
+
 public class ClassTypeResolverJava8Test {
 
     @Test
@@ -28,6 +37,37 @@ public class ClassTypeResolverJava8Test {
         ASTCompilationUnit acu = parseAndTypeResolveForClass18(UsesRepeatableAnnotations.class);
     }
 
+    @Test
+    public void testThisExpression() throws JaxenException {
+        ASTCompilationUnit acu = parseAndTypeResolveForClass18(ThisExpression.class);
+
+        List<ASTPrimaryExpression> expressions = convertList(
+                acu.findChildNodesWithXPath("//VariableInitializer/Expression/PrimaryExpression"),
+                ASTPrimaryExpression.class);
+        List<ASTPrimaryPrefix> prefixes = convertList(
+                acu.findChildNodesWithXPath("//VariableInitializer/Expression/PrimaryExpression/PrimaryPrefix"),
+                ASTPrimaryPrefix.class);
+
+        int index = 0;
+
+        assertEquals(ThisExpression.class, expressions.get(index).getType());
+        assertEquals(ThisExpression.class, prefixes.get(index++).getType());
+        assertEquals(ThisExpression.PrimaryThisInterface.class, expressions.get(index).getType());
+        assertEquals(ThisExpression.PrimaryThisInterface.class, prefixes.get(index++).getType());
+
+        // Make sure we got them all
+        assertEquals("All expressions not tested", index, expressions.size());
+        assertEquals("All expressions not tested", index, prefixes.size());
+    }
+
+    private static <T> List<T> convertList(List<Node> nodes, Class<T> target) {
+        List<T> converted = new ArrayList<>();
+        for (Node n : nodes) {
+            converted.add(target.cast(n));
+        }
+        return converted;
+    }
+
     private ASTCompilationUnit parseAndTypeResolveForClass18(Class<?> clazz) {
         return parseAndTypeResolveForClass(clazz, "1.8");
     }

pmd-java8/src/test/java/net/sourceforge/pmd/typeresolution/testdata/ThisExpression.java

@@ -0,0 +1,15 @@
+package net.sourceforge.pmd.typeresolution.testdata;
+
+public class ThisExpression {
+
+    public void foo() {
+        ((Runnable) (() -> { ThisExpression b = this; })).run();
+    }
+
+    public interface PrimaryThisInterface {
+        default void foo() {
+            PrimaryThisInterface a = this;
+        }
+    }
+}
+