OpenRewrite recipe best practices

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

Author: timtebeek

src/test/java/org/openrewrite/java/testing/cleanup/AssertEqualsNullToAssertNullTest.java

@@ -16,6 +16,7 @@
 package org.openrewrite.java.testing.cleanup;
 
 import org.junit.jupiter.api.Test;
+import org.openrewrite.DocumentExample;
 import org.openrewrite.InMemoryExecutionContext;
 import org.openrewrite.Issue;
 import org.openrewrite.java.JavaParser;
@@ -34,6 +35,40 @@ public void defaults(RecipeSpec spec) {
           .recipe(new AssertEqualsNullToAssertNull());
     }
 
+    @DocumentExample
+    @Test
+    void simplifyToAssertNullKotlin() {
+        rewriteRun(
+          //language=kotlin
+          kotlin(
+            """
+              import org.junit.jupiter.api.Assertions.assertEquals
+
+              class FooTest {
+                  fun test(values: List<String?>) {
+                      assertEquals(values[0], null)
+                      assertEquals(null, values[0])
+                      assertEquals(values[0], null, "message")
+                      assertEquals(null, values[0], "message")
+                  }
+              }
+              """,
+            """
+              import org.junit.jupiter.api.Assertions.assertNull
+
+              class FooTest {
+                  fun test(values: List<String?>) {
+                      assertNull(values[0])
+                      assertNull(values[0])
+                      assertNull(values[0], "message")
+                      assertNull(values[0], "message")
+                  }
+              }
+              """
+          )
+        );
+    }
+
     @Issue("https://github.com/openrewrite/rewrite-testing-frameworks/issues/200")
     @SuppressWarnings({"ConstantConditions", "SimplifiableAssertion"})
     @Test
@@ -107,37 +142,4 @@ void test() {
             )
         );
     }
-
-    @Test
-    void simplifyToAssertNullKotlin() {
-        rewriteRun(
-          //language=kotlin
-          kotlin(
-            """
-              import org.junit.jupiter.api.Assertions.assertEquals
-
-              class FooTest {
-                  fun test(values: List<String?>) {
-                      assertEquals(values[0], null)
-                      assertEquals(null, values[0])
-                      assertEquals(values[0], null, "message")
-                      assertEquals(null, values[0], "message")
-                  }
-              }
-              """,
-            """
-              import org.junit.jupiter.api.Assertions.assertNull
-
-              class FooTest {
-                  fun test(values: List<String?>) {
-                      assertNull(values[0])
-                      assertNull(values[0])
-                      assertNull(values[0], "message")
-                      assertNull(values[0], "message")
-                  }
-              }
-              """
-          )
-        );
-    }
 }