Joda-time: Make safe migration optional (#811)

* Joda-time: Make safe migration optional

* Skip scan if safe mode is disabled

* Handle NPE

* Fix flaky test

* Remove unused import

* Rename option to `safeMigrationOnly`

---------

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

Author: amishra-u

src/main/java/org/openrewrite/java/migrate/joda/JodaTimeRecipe.java

@@ -15,12 +15,11 @@
  */
 package org.openrewrite.java.migrate.joda;
 
+import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.Value;
 import org.jspecify.annotations.Nullable;
-import org.openrewrite.ExecutionContext;
-import org.openrewrite.Preconditions;
-import org.openrewrite.ScanningRecipe;
-import org.openrewrite.TreeVisitor;
+import org.openrewrite.*;
 import org.openrewrite.java.search.UsesType;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.J.VariableDeclarations.NamedVariable;
@@ -30,7 +29,23 @@
 
 import static java.util.Collections.emptyList;
 
+@EqualsAndHashCode(callSuper = false)
+@Value
 public class JodaTimeRecipe extends ScanningRecipe<JodaTimeRecipe.Accumulator> {
+
+    /**
+     * Controls whether additional safety checks are performed during the migration process.
+     * When enabled, the recipe will verify that expressions are safe to migrate before performing the migration.
+     * This helps prevent potential issues or bugs that might arise from automatic migration.
+     */
+    @Option(displayName = "Safe migration only",
+      description = "When enabled, performs additional safety checks to verify that expressions are safe to migrate before converting them. " +
+                    "Safety checks include analyzing method parameters, return values, and variable usages across class boundaries.",
+      required = false
+    )
+    @Nullable
+    Boolean safeMigrationOnly;
+
     @Override
     public String getDisplayName() {
         return "Migrate Joda-Time to Java time";
@@ -48,12 +63,12 @@ public Accumulator getInitialValue(ExecutionContext ctx) {
 
     @Override
     public TreeVisitor<?, ExecutionContext> getScanner(Accumulator acc) {
-        return new JodaTimeScanner(acc);
+        return new JodaTimeScanner(acc, Boolean.TRUE.equals(safeMigrationOnly));
     }
 
     @Override
     public TreeVisitor<?, ExecutionContext> getVisitor(Accumulator acc) {
-        JodaTimeVisitor jodaTimeVisitor = new JodaTimeVisitor(acc, true, new LinkedList<>());
+        JodaTimeVisitor jodaTimeVisitor = new JodaTimeVisitor(acc, Boolean.TRUE.equals(safeMigrationOnly), new LinkedList<>());
         return Preconditions.check(new UsesType<>("org.joda.time.*", true), jodaTimeVisitor);
     }
 

src/main/java/org/openrewrite/java/migrate/joda/JodaTimeScanner.java

@@ -41,15 +41,21 @@ class JodaTimeScanner extends ScopeAwareVisitor {
 
     @Getter
     private final JodaTimeRecipe.Accumulator acc;
+    private final boolean safeMigrationOnly;
 
     private final Map<NamedVariable, Set<NamedVariable>> varDependencies = new HashMap<>();
     private final Map<JavaType, Set<String>> unsafeVarsByType = new HashMap<>();
     private final Map<JavaType.Method, Set<NamedVariable>> methodReferencedVars = new HashMap<>();
     private final Map<JavaType.Method, Set<UnresolvedVar>> methodUnresolvedReferencedVars = new HashMap<>();
 
     public JodaTimeScanner(JodaTimeRecipe.Accumulator acc) {
+        this(acc, true);
+    }
+
+    public JodaTimeScanner(JodaTimeRecipe.Accumulator acc, boolean safeMigrationOnly) {
         super(new LinkedList<>());
         this.acc = acc;
+        this.safeMigrationOnly = safeMigrationOnly;
     }
 
     @Override
@@ -67,6 +73,9 @@ public Javadoc visitReference(Javadoc.Reference reference, ExecutionContext ctx)
 
     @Override
     public J visitCompilationUnit(J.CompilationUnit cu, ExecutionContext ctx) {
+        if (!safeMigrationOnly) { // skip scan if safe mode is disabled
+            return cu;
+        }
         super.visitCompilationUnit(cu, ctx);
         Set<NamedVariable> allReachable = new HashSet<>();
         for (NamedVariable var : acc.getUnsafeVars()) {

src/test/java/org/openrewrite/java/migrate/joda/JodaTimeRecipeTest.java

@@ -30,7 +30,7 @@ class JodaTimeRecipeTest implements RewriteTest {
     @Override
     public void defaults(RecipeSpec spec) {
         spec
-          .recipe(new JodaTimeRecipe())
+          .recipe(new JodaTimeRecipe(true))
           .parser(JavaParser.fromJavaVersion().classpath("joda-time"));
     }