Correctly preserve prefix in StringLiteralEquality

Fixes: #130

Author: knutwannheden

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

@@ -69,7 +69,7 @@ private boolean isStringLiteral(Expression expression) {
             private J.MethodInvocation asEqualsMethodInvocation(J.Binary binary) {
                 return new J.MethodInvocation(
                         Tree.randomId(),
-                        binary.getPrefix(),
+                        Space.EMPTY,
                         Markers.EMPTY,
                         new JRightPadded<>(binary.getLeft().withPrefix(Space.EMPTY), Space.EMPTY, Markers.EMPTY),
                         null,
@@ -109,10 +109,9 @@ public J visitBinary(J.Binary binary, ExecutionContext ctx) {
                 if (isStringLiteral(binary.getLeft()) || isStringLiteral(binary.getRight())) {
                     J after = null;
                     if (binary.getOperator() == J.Binary.Type.Equal) {
-                        after = asEqualsMethodInvocation(binary);
+                        after = asEqualsMethodInvocation(binary).withPrefix(binary.getPrefix());
                     } else if (binary.getOperator() == J.Binary.Type.NotEqual) {
-                        J.MethodInvocation mi = asEqualsMethodInvocation(binary);
-                        after = asNegatedUnary(mi);
+                        after = asNegatedUnary(asEqualsMethodInvocation(binary)).withPrefix(binary.getPrefix());
                     }
                     if (after != null) {
                         doAfterVisit(new EqualsAvoidsNull().getVisitor());

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

@@ -51,7 +51,7 @@ public String getString() {
                   }
 
                   public void method(String str) {
-                      if (str == "test") ;
+                      if (str.length() > 1 && str == "test") ;
                       if ("test" == str) ;
                       if ("test" == "test") ;
                       if ("test" == new String("test")) ;
@@ -78,7 +78,7 @@ public String getString() {
                   }
 
                   public void method(String str) {
-                      if ("test".equals(str)) ;
+                      if (str.length() > 1 && "test".equals(str)) ;
                       if ("test".equals(str)) ;
                       if ("test".equals("test")) ;
                       if ("test".equals(new String("test"))) ;
@@ -113,7 +113,7 @@ public String getString() {
                   }
 
                   public void method(String str) {
-                      if (str != "test") ;
+                      if (str.length() > 1 && str != "test") ;
                       if ("test" != str) ;
                       if ("test" != "test") ;
                       if ("test" != new String("test")) ;
@@ -131,7 +131,7 @@ public String getString() {
                   }
 
                   public void method(String str) {
-                      if (!"test".equals(str)) ;
+                      if (str.length() > 1 && !"test".equals(str)) ;
                       if (!"test".equals(str)) ;
                       if (!"test".equals("test")) ;
                       if (!"test".equals(new String("test"))) ;