@PackageRecipeTags annotation on package-info

Adds a package level annotation for adding tags to recipes at the
package-level scope.

Signed-off-by: Jonathan Leitschuh <[email protected]>

rewrite-core/src/main/java/org/openrewrite/PackageRecipeTags.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite;
+
+import org.openrewrite.config.RecipeDescriptor;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * A package-level annotation that can be used to tag all {@link Recipe} within a given package and children
+ * packages with a given tag.
+ * <p>
+ * This annotation is useful for tagging all recipes within a package with a given tag, without having to
+ * add it manually to each overridden {@link Recipe#getTags()} method.
+ * <p>
+ * The tag will not be accessible via {@link Recipe#getTags()}, but will be accessible via {@link RecipeDescriptor#getTags()}
+ * when the {@link RecipeDescriptor} is created via {@link Recipe#getDescriptor()}.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.PACKAGE})
+public @interface PackageRecipeTags {
+    String[] value() default {};
+}

rewrite-core/src/main/java/org/openrewrite/Recipe.java

@@ -223,10 +223,45 @@ protected RecipeDescriptor createRecipeDescriptor() {
         } catch (URISyntaxException e) {
             throw new RuntimeException(e);
         }
+        Set<String> allTags = new LinkedHashSet<>(getTags());
+        allTags.addAll(getTagsForPackageAndParent(getClass().getPackage()));
+
+        return new RecipeDescriptor(
+                getName(),
+                getDisplayName(),
+                getDescription(),
+                allTags,
+                getEstimatedEffortPerOccurrence(),
+                options,
+                recipeList1,
+                getDataTableDescriptors(),
+                getMaintainers(),
+                getContributors(),
+                getExamples(),
+                recipeSource
+        );
+    }
 
-        return new RecipeDescriptor(getName(), getDisplayName(), getDescription(), getTags(),
-                getEstimatedEffortPerOccurrence(), options, recipeList1, getDataTableDescriptors(),
-                getMaintainers(), getContributors(), getExamples(), recipeSource);
+    /**
+     * Finds all {@link PackageRecipeTags} annotations on the package of the given class and all parent packages.
+     *
+     * @return The set of tags found.
+     */
+    private static Set<String> getTagsForPackageAndParent(@Nullable Package p) {
+        if (p == null) {
+            return Collections.emptySet();
+        }
+        Set<String> tags = new LinkedHashSet<>();
+        PackageRecipeTags packageTags = p.getAnnotation(PackageRecipeTags.class);
+        if (packageTags != null) {
+            tags.addAll(Arrays.asList(packageTags.value()));
+        }
+        int lastDot = p.getName().lastIndexOf('.');
+        if (lastDot > 0) {
+            String parentPackage = p.getName().substring(0, lastDot);
+            tags.addAll(getTagsForPackageAndParent(Package.getPackage(parentPackage)));
+        }
+        return tags;
     }
 
     private List<OptionDescriptor> getOptionDescriptors(Class<?> recipeClass) {

rewrite-core/src/test/java/org/openrewrite/tags/PackageRecipeTagsAnnotationTest.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.tags;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.Recipe;
+import org.openrewrite.config.RecipeDescriptor;
+import org.openrewrite.tags.child.ChildRecipeWithNoTags;
+
+import java.util.Collections;
+import java.util.Set;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class PackageRecipeTagsAnnotationTest {
+
+    private static class RecipeWithNoTags extends Recipe {
+        @Override
+        public String getDisplayName() {
+            return "Recipe with no tags";
+        }
+
+        @Override
+        public String getDescription() {
+            return "It's tag-less!";
+        }
+
+        @Override
+        public Set<String> getTags() {
+            // Look ma, no tags! 🤣
+            return Collections.emptySet();
+        }
+    }
+
+    @Test
+    void testRecipeWithNoTags() {
+        RecipeWithNoTags recipe = new RecipeWithNoTags();
+        RecipeDescriptor descriptor = recipe.getDescriptor();
+        assertThat(descriptor.getTags())
+          .withFailMessage("Expected tag to be pulled from package-info.java")
+          .contains("What a fun tag!");
+    }
+
+    @Test
+    void testChildRecipeWithNoTags() {
+        ChildRecipeWithNoTags recipe = new ChildRecipeWithNoTags();
+        RecipeDescriptor descriptor = recipe.getDescriptor();
+        assertThat(descriptor.getTags())
+          .withFailMessage("Expected tag to be pulled from parent package-info.java")
+          .contains("What a fun tag!");
+    }
+}

rewrite-core/src/test/java/org/openrewrite/tags/child/ChildRecipeWithNoTags.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.openrewrite.tags.child;
+
+import org.openrewrite.Recipe;
+
+public class ChildRecipeWithNoTags extends Recipe {
+
+    @Override
+    public String getDisplayName() {
+        return "Recipe with no tags";
+    }
+
+    @Override
+    public String getDescription() {
+        return "It's tag-less!";
+    }
+
+}

rewrite-core/src/test/java/org/openrewrite/tags/child/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package org.openrewrite.tags.child;
+
+import io.micrometer.core.lang.NonNullApi;

rewrite-core/src/test/java/org/openrewrite/tags/package-info.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2024 the original author or authors.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@PackageRecipeTags({"What a fun tag!"})
+@NonNullApi
+package org.openrewrite.tags;
+
+import org.openrewrite.PackageRecipeTags;
+import org.openrewrite.internal.lang.NonNullApi;