Fix prefix formatting on IsEmptyCallOnCollections

[aegershman]

Problem

Describe the issue you are experiencing.

see diff

Expected behavior

Describe what you expected to see.

see diff

Example diff

   public static List<CorrelationId> getVariablesSetAndUsed(RelNode rel0,
       RelNode rel1) {
     Set<CorrelationId> set = getVariablesSet(rel0);
-    if (set.size() == 0) {
+    if (set.isEmpty()) {
       return ImmutableList.of();
     }
     Set<CorrelationId> used = getVariablesUsed(rel1);
-    if (used.size() == 0) {
+    if (used.isEmpty()) {
       return ImmutableList.of();
     }
     final List<CorrelationId> result = new ArrayList<>();
   @Experimental
   public static RelNode propagateRelHints(RelNode originalRel, RelNode equiv) {
     if (!(originalRel instanceof Hintable)
-        || ((Hintable) originalRel).getHints().size() == 0) {
+        ||((Hintable) originalRel).getHints().isEmpty()) {
       return equiv;
     }
     final RelShuttle shuttle = new SubTreeHintPropagateShuttle(
         rightKeys,
         filterNulls,
         nonEquiList);
-    return nonEquiList.size() == 0;
+    returnnonEquiList.isEmpty();
   }
 
   /**
 
     private static RelHint copyWithAppendPath(RelHint hint,
         List<Integer> appendPaths) {
-      if (appendPaths.size() == 0) {
+      if (appendPaths.isEmpty()) {
         return hint;
       } else {
         List<Integer> newPath = new ArrayList<>(hint.inheritPath);
     private static RelNode resetHints(Hintable hintable) {
       if (hintable.getHints().size() > 0) {
         final List<RelHint> resetHints = hintable.getHints().stream()
-            .filter(hint -> hint.inheritPath.size() == 0)
+            .filter(hint ->hint.inheritPath.isEmpty())
             .collect(Collectors.toList());
         return hintable.withHints(resetHints);
       } else {

Recipes in example diff:

• org.openrewrite.java.cleanup.IsEmptyCallOnCollections

References:

• Recipe ID: OHafc
• Recipe Name: "Use Collections#isEmpty() instead of comparing size()"
• Repository: apache/calcite
• Created at Fri Oct 15 2021 01:39:26 GMT-0500 (Central Daylight Time)

[aegershman]

notes on parsing error when in the context of lambdas:

J.Binary is an Expression and thus doesn't currently have coordinates. So when we return the generated J.Binary it's at a location for the .size() method invocation within that Binary.

In lieu of being able to replace the J.Binary using the J.Binary coordinates directly, we'll manually set the prefix. We could include J.Binary Coordinates, or expand Coordinates to include Coordinates for Expressions, but at the time of writing this that is a bigger scope than manually setting the prefix here.

---

This leads to a parsing issue when replacing the result within a lambda, b/c the end result is expected to be an Expression. Something close to this stub is generated, which is not a statement / doesn't appear to be compileable in a way to get extracted. Checking

class Test {
    static <T> Stream<List<T>> method(Stream<List<T>> stream) {
        if (true) {
            s -> {
                if (true) {
                    Object o =
                            /*__TEMPLATE__*/__P__.<java.util.Collection>/*__p1__*/p().isEmpty()
                }
                return null;
            };
        }
        return null;
    }
}

[aegershman]

Moving other content to #1120