OpenRewrite recipe best practices

Use this link to re-run the recipe: https://app.moderne.io/recipes/org.openrewrite.recipes.rewrite.OpenRewriteRecipeBestPractices?organizationId=QUxML01vZGVybmUvTW9kZXJuZSArIE9wZW5SZXdyaXRl

Co-authored-by: Moderne <team@moderne.io>

Author: timtebeek

src/main/java/org/openrewrite/java/migrate/search/ModuleHasKotlinSource.java

@@ -41,17 +41,11 @@ public class ModuleHasKotlinSource extends ScanningRecipe<Set<JavaProject>> {
     @Nullable
     Boolean invertMarking;
 
-    @Override
-    public String getDisplayName() {
-        return "Module has Kotlin source files";
-    }
+    String displayName = "Module has Kotlin source files";
 
-    @Override
-    public String getDescription() {
-        return "Marks all files in modules that contain at least one Kotlin source file (`.kt`). " +
-                "Intended as a precondition to scope recipes to projects that actually compile Kotlin, " +
-                "as opposed to projects that merely pick up `kotlin-stdlib` transitively.";
-    }
+    String description = "Marks all files in modules that contain at least one Kotlin source file (`.kt`). " +
+            "Intended as a precondition to scope recipes to projects that actually compile Kotlin, " +
+            "as opposed to projects that merely pick up `kotlin-stdlib` transitively.";
 
     @Override
     public Set<JavaProject> getInitialValue(ExecutionContext ctx) {

src/test/java/org/openrewrite/java/migrate/util/MigrateCollectionsSingletonMapTest.java

@@ -16,6 +16,7 @@
 package org.openrewrite.java.migrate.util;
 
 import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
 import org.openrewrite.Issue;
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;
@@ -31,9 +32,9 @@ public void defaults(RecipeSpec spec) {
         spec.recipe(new MigrateCollectionsSingletonMap());
     }
 
-    @Issue("https://github.com/openrewrite/rewrite-migrate-java/issues/72")
+    @DocumentExample
     @Test
-    void singletonMap() {
+    void singletonMapAsArgument() {
         //language=java
         rewriteRun(
           version(
@@ -42,14 +43,20 @@ void singletonMap() {
                 import java.util.*;
 
                 class Test {
-                    Map<String,String> set = Collections.singletonMap("hello", "world");
+                    void take(Map<String, Object> m) {}
+                    void call(String key, Object value) {
+                        take(Collections.singletonMap(key, value));
+                    }
                 }
                 """,
               """
                 import java.util.Map;
 
                 class Test {
-                    Map<String,String> set = Map.of("hello", "world");
+                    void take(Map<String, Object> m) {}
+                    void call(String key, Object value) {
+                        take(Map.of(key, value));
+                    }
                 }
                 """
             ),
@@ -60,25 +67,23 @@ class Test {
 
     @Issue("https://github.com/openrewrite/rewrite-migrate-java/issues/72")
     @Test
-    void singletonMapCustomType() {
+    void singletonMap() {
         //language=java
         rewriteRun(
           version(
             java(
               """
                 import java.util.*;
-                import java.time.LocalDate;
 
                 class Test {
-                    Map<String,LocalDate> map = Collections.singletonMap("date", LocalDate.now());
+                    Map<String,String> set = Collections.singletonMap("hello", "world");
                 }
                 """,
               """
                 import java.util.Map;
-                import java.time.LocalDate;
 
                 class Test {
-                    Map<String,LocalDate> map = Map.of("date", LocalDate.now());
+                    Map<String,String> set = Map.of("hello", "world");
                 }
                 """
             ),
@@ -87,19 +92,27 @@ class Test {
         );
     }
 
-    @Issue("https://github.com/openrewrite/rewrite-migrate-java/issues/571")
+    @Issue("https://github.com/openrewrite/rewrite-migrate-java/issues/72")
     @Test
-    void shouldNotConvertLiteralNull() {
+    void singletonMapCustomType() {
         //language=java
         rewriteRun(
           version(
             java(
               """
                 import java.util.*;
+                import java.time.LocalDate;
 
                 class Test {
-                    Map<String, String> mapWithNullKey = Collections.singletonMap(null, "foo");
-                    Map<String, String> mapWithNullValue = Collections.singletonMap("bar", null);
+                    Map<String,LocalDate> map = Collections.singletonMap("date", LocalDate.now());
+                }
+                """,
+              """
+                import java.util.Map;
+                import java.time.LocalDate;
+
+                class Test {
+                    Map<String,LocalDate> map = Map.of("date", LocalDate.now());
                 }
                 """
             ),
@@ -108,8 +121,9 @@ class Test {
         );
     }
 
+    @Issue("https://github.com/openrewrite/rewrite-migrate-java/issues/571")
     @Test
-    void singletonMapAsArgument() {
+    void shouldNotConvertLiteralNull() {
         //language=java
         rewriteRun(
           version(
@@ -118,20 +132,8 @@ void singletonMapAsArgument() {
                 import java.util.*;
 
                 class Test {
-                    void take(Map<String, Object> m) {}
-                    void call(String key, Object value) {
-                        take(Collections.singletonMap(key, value));
-                    }
-                }
-                """,
-              """
-                import java.util.Map;
-
-                class Test {
-                    void take(Map<String, Object> m) {}
-                    void call(String key, Object value) {
-                        take(Map.of(key, value));
-                    }
+                    Map<String, String> mapWithNullKey = Collections.singletonMap(null, "foo");
+                    Map<String, String> mapWithNullValue = Collections.singletonMap("bar", null);
                 }
                 """
             ),