Enable custom Serial Version UID (#541)

* Enable custom Serial Version UID

To be able to choose from `1`, `1L`, or any other value.

* Apply suggestions from code review

* Minor polish

---------

Co-authored-by: Tim te Beek <[email protected]>
Co-authored-by: Tim te Beek <[email protected]>

Author: yuri1969

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

@@ -15,6 +15,8 @@
  */
 package org.openrewrite.staticanalysis;
 
+import lombok.EqualsAndHashCode;
+import lombok.Value;
 import org.jspecify.annotations.Nullable;
 import org.openrewrite.*;
 import org.openrewrite.internal.ListUtils;
@@ -32,8 +34,17 @@
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+@Value
+@EqualsAndHashCode(callSuper = false)
 public class AddSerialVersionUidToSerializable extends Recipe {
 
+    @Option(displayName = "New serial version UID",
+            description = "Value of the added serial version UID.",
+            example = "42L",
+            required = false)
+    @Nullable
+    String uid;
+
     @Override
     public String getDisplayName() {
         return "Add `serialVersionUID` to a `Serializable` class when missing";
@@ -54,7 +65,7 @@ public Set<String> getTags() {
     @Override
     public TreeVisitor<?, ExecutionContext> getVisitor() {
         return new JavaIsoVisitor<ExecutionContext>() {
-            final JavaTemplate template = JavaTemplate.builder("private static final long serialVersionUID = 1;").build();
+            final JavaTemplate template = JavaTemplate.builder(String.format("private static final long serialVersionUID = %s;", uid != null ? uid : "1")).build();
 
             @Override
             public J.MethodDeclaration visitMethodDeclaration(J.MethodDeclaration method, ExecutionContext ctx) {
@@ -103,7 +114,7 @@ private J.VariableDeclarations maybeFixVariableDeclarations(J.VariableDeclaratio
                     varDecls = varDecls.withModifiers(Arrays.asList(
                             new J.Modifier(Tree.randomId(), Space.EMPTY, Markers.EMPTY, null, J.Modifier.Type.Private, Collections.emptyList()),
                             new J.Modifier(Tree.randomId(), Space.SINGLE_SPACE, Markers.EMPTY, null, J.Modifier.Type.Static, Collections.emptyList()),
-                            new J.Modifier(Tree.randomId(), Space.SINGLE_SPACE, Markers.EMPTY, null, J.Modifier.Type.Final,   Collections.emptyList())
+                            new J.Modifier(Tree.randomId(), Space.SINGLE_SPACE, Markers.EMPTY, null, J.Modifier.Type.Final, Collections.emptyList())
                     ));
                 }
                 if (TypeUtils.asPrimitive(varDecls.getType()) != JavaType.Primitive.Long) {

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

@@ -62,7 +62,7 @@ class Example implements Serializable {
     void shouldAddToNewFieldWhenChained() {
         rewriteRun(
           spec -> spec.recipes(
-            new AddSerialVersionUidToSerializable(),
+            new AddSerialVersionUidToSerializable(null),
             new AddSerialAnnotationToSerialVersionUID()),
           //language=java
           java(

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

@@ -27,7 +27,7 @@ class AddSerialVersionUidToSerializableTest implements RewriteTest {
 
     @Override
     public void defaults(RecipeSpec spec) {
-        spec.recipe(new AddSerialVersionUidToSerializable());
+        spec.recipe(new AddSerialVersionUidToSerializable(null));
     }
 
     @DocumentExample
@@ -57,6 +57,33 @@ public class Example implements Serializable {
         );
     }
 
+    @Test
+    void addCustomSerialVersionUID() {
+        rewriteRun(
+          spec -> spec.recipe(new AddSerialVersionUidToSerializable("1L")),
+          //language=java
+          java(
+            """
+              import java.io.Serializable;
+
+              public class Example implements Serializable {
+                  private String fred;
+                  private int numberOfFreds;
+              }
+              """,
+            """
+              import java.io.Serializable;
+
+              public class Example implements Serializable {
+                  private static final long serialVersionUID = 1L;
+                  private String fred;
+                  private int numberOfFreds;
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void doNothingNotSerializable() {
         rewriteRun(
@@ -171,6 +198,25 @@ public class Example implements Serializable {
         );
     }
 
+    @Test
+    void customUidKeepsUidAlreadyPresent() {
+        rewriteRun(
+          spec -> spec.recipe(new AddSerialVersionUidToSerializable("1L")),
+          //language=java
+          java(
+            """
+              import java.io.Serializable;
+
+              public class Example implements Serializable {
+                  private static final long serialVersionUID = 1;
+                  private String fred;
+                  private int numberOfFreds;
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void methodDeclarationsAreNotVisited() {
         rewriteRun(

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

@@ -92,7 +92,7 @@ static void method(String someField) {
                       String localVariable = someField;
                   }
               }
-                """
+              """
           )
         );
     }
@@ -759,7 +759,7 @@ public abstract class A {
 
                   public abstract void method(int n);
               }
-                """
+              """
           )
         );
     }