Convert most of the checks as used for UseLombokGetter

Author: timtebeek

src/main/java/org/openrewrite/java/migrate/lombok/LombokUtils.java

@@ -21,11 +21,7 @@
 import org.openrewrite.java.tree.Expression;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.JavaType;
-import org.openrewrite.java.tree.Statement;
 
-import java.util.List;
-
-import static java.util.stream.Collectors.toList;
 import static lombok.AccessLevel.*;
 import static org.openrewrite.java.tree.J.Modifier.Type.*;
 
@@ -66,40 +62,6 @@ static boolean isGetter(J.MethodDeclaration method) {
         return false;
     }
 
-    static boolean isEffectivelySetter(J.MethodDeclaration method) {
-        boolean isVoid = "void".equals(method.getType().toString());
-        List<Statement> actualParameters = method.getParameters().stream()
-                .filter(s -> !(s instanceof J.Empty))
-                .collect(toList());
-        boolean oneParam = actualParameters.size() == 1;
-        if (!isVoid || !oneParam)
-            return false;
-
-        J.VariableDeclarations variableDeclarations = (J.VariableDeclarations) actualParameters.get(0);
-        J.VariableDeclarations.NamedVariable param = variableDeclarations.getVariables().get(0);
-        String paramName = param.getName().toString();
-
-        boolean singularStatement = method.getBody() != null //abstract methods can be null
-                && method.getBody().getStatements().size() == 1 &&
-                method.getBody().getStatements().get(0) instanceof J.Assignment;
-
-        if (!singularStatement) {
-            return false;
-        }
-        J.Assignment assignment = (J.Assignment) method.getBody().getStatements().get(0);
-
-        J.FieldAccess fieldAccess = (J.FieldAccess) assignment.getVariable();
-
-        return
-                // assigned value is exactly the parameter
-                assignment.getAssignment().toString().equals(paramName) // type of parameter and field have to match
-                        &&
-
-                        // type of parameter and field have to match
-                        param.getType().equals(fieldAccess.getType());
-
-    }
-
     private static boolean hasMatchingTypeAndName(J.MethodDeclaration method, @Nullable JavaType type, String simpleName) {
         if (method.getType() == type) {
             String deriveGetterMethodName = deriveGetterMethodName(type, simpleName);
@@ -121,8 +83,46 @@ private static String deriveGetterMethodName(@Nullable JavaType type, String fie
         return "get" + StringUtils.capitalize(fieldName);
     }
 
-    static String deriveSetterMethodName(JavaType.Variable fieldType) {
-        return "set" + StringUtils.capitalize(fieldType.getName());
+    static boolean isSetter(J.MethodDeclaration method) {
+        // Check return type: void
+        if (method.getType() != JavaType.Primitive.Void) {
+            return false;
+        }
+        // Check signature: single parameter
+        if (method.getParameters().size() != 1 || method.getParameters().get(0) instanceof J.Empty) {
+            return false;
+        }
+        // Check body: just an assignment
+        if (method.getBody() == null || //abstract methods can be null
+                method.getBody().getStatements().size() != 1 ||
+                !(method.getBody().getStatements().get(0) instanceof J.Assignment)) {
+            return false;
+        }
+        J.Assignment assignment = (J.Assignment) method.getBody().getStatements().get(0);
+        J.FieldAccess fieldAccess = (J.FieldAccess) assignment.getVariable();
+        if (!method.getSimpleName().equals(deriveSetterMethodName(fieldAccess))) {
+            return false;
+        }
+
+        // Check argument is assigned to field
+        J.VariableDeclarations variableDeclarations = (J.VariableDeclarations) method.getParameters().get(0);
+        J.VariableDeclarations.NamedVariable param = variableDeclarations.getVariables().get(0);
+        JavaType paramType = param.getType();
+        String paramName = param.getName().toString();
+
+
+        return
+                // assigned value is exactly the parameter
+                assignment.getAssignment().toString().equals(paramName) // type of parameter and field have to match
+                        &&
+
+                        // type of parameter and field have to match
+                        param.getType().equals(fieldAccess.getType());
+
+    }
+
+    private static String deriveSetterMethodName(J.FieldAccess fieldAccess) {
+        return "set" + StringUtils.capitalize(fieldAccess.getSimpleName());
     }
 
     static AccessLevel getAccessLevel(J.MethodDeclaration methodDeclaration) {

src/main/java/org/openrewrite/java/migrate/lombok/UseLombokSetter.java

@@ -42,12 +42,7 @@ public String getDisplayName() {
     @Override
     public String getDescription() {
         //language=markdown
-        return "Convert trivial setter methods to `@Setter` annotations on their respective fields.\n\n" +
-                "Limitations:\n\n" +
-                " - Does not add a dependency to Lombok, users need to do that manually\n" +
-                " - Ignores fields that are declared on the same line as others, e.g. `private int foo, bar; " +
-                "Users who have such fields are advised to separate them beforehand with [org.openrewrite.staticanalysis.MultipleVariableDeclaration](https://docs.openrewrite.org/recipes/staticanalysis/multiplevariabledeclarations).\n" +
-                " - Does not offer any of the configuration keys listed in https://projectlombok.org/features/GetterSetter.";
+        return "Convert trivial setter methods to `@Setter` annotations on their respective fields.";
     }
 
     @Override
@@ -57,31 +52,18 @@ public Set<String> getTags() {
 
     @Override
     public TreeVisitor<?, ExecutionContext> getVisitor() {
-        return new MethodRemover();
-    }
-
-    @Value
-    @EqualsAndHashCode(callSuper = false)
-    private static class MethodRemover extends JavaIsoVisitor<ExecutionContext> {
-
-        @Override
-        public J.@Nullable MethodDeclaration visitMethodDeclaration(J.MethodDeclaration method, ExecutionContext ctx) {
-            if (LombokUtils.isEffectivelySetter(method)) {
-                J.Assignment assignment_ = (J.Assignment) method.getBody().getStatements().get(0);
-                J.FieldAccess fieldAccess = (J.FieldAccess) assignment_.getVariable();
-
-                Variable fieldType = fieldAccess.getName().getFieldType();
-                boolean nameMatch = method.getSimpleName().equals(LombokUtils.deriveSetterMethodName(fieldType));
-                if (nameMatch) {
-                    doAfterVisit(new FieldAnnotator(
-                            Setter.class,
-                            fieldType,
-                            LombokUtils.getAccessLevel(method)
-                    ));
+        return new JavaIsoVisitor<ExecutionContext>() {
+            @Override
+            public J.@Nullable MethodDeclaration visitMethodDeclaration(J.MethodDeclaration method, ExecutionContext ctx) {
+                if (LombokUtils.isSetter(method)) {
+                    J.Assignment assignment_ = (J.Assignment) method.getBody().getStatements().get(0);
+                    J.FieldAccess fieldAccess = (J.FieldAccess) assignment_.getVariable();
+                    Variable fieldType = fieldAccess.getName().getFieldType();
+                    doAfterVisit(new FieldAnnotator(Setter.class, fieldType, LombokUtils.getAccessLevel(method)));
                     return null; //delete
                 }
+                return method;
             }
-            return method;
-        }
+        };
     }
 }