Fix bug in InstanceOfPatternMatch getting the variable name from th…

…e name of a nested class (#291)

Co-authored-by: Hoan Nguyen <hoanamzn@amazon.com>

src/main/java/org/openrewrite/staticanalysis/InstanceOfPatternMatch.java

@@ -364,9 +364,7 @@ public String variableName(@Nullable JavaType type) {
  return name;
  } else if (type instanceof JavaType.FullyQualified) {
  String className = ((JavaType.FullyQualified) type).getClassName();
- if (className.indexOf('.') > 0) {
- className = className.substring(className.lastIndexOf('.'));
- }
+ className = className.substring(className.lastIndexOf('.') + 1);
  String baseName = null;
  switch (style) {
  case SHORT:

src/test/java/org/openrewrite/staticanalysis/InstanceOfPatternMatchTest.java

@@ -221,6 +221,41 @@ void test(Object o) {
  );
  }
 
+ @Test
+ void conflictingVariableOfNestedType() {
+ rewriteRun(
+ //language=java
+ java(
+ """
+ import java.util.Map;
+ 
+ public class A {
+ void test(Object o) {
+ Map.Entry entry = null;
+ if (o instanceof Map.Entry) {
+ entry = (Map.Entry) o;
+ }
+ System.out.println(entry);
+ }
+ }
+ """,
+ """
+ import java.util.Map;
+ 
+ public class A {
+ void test(Object o) {
+ Map.Entry entry = null;
+ if (o instanceof Map.Entry entry1) {
+ entry = entry1;
+ }
+ System.out.println(entry);
+ }
+ }
+ """
+ )
+ );
+ }
+
  @Issue("https://github.com/openrewrite/rewrite/issues/2787")
  @Disabled
  @Test