YamlValue trait (#5145)

rewrite-yaml/src/main/java/org/openrewrite/yaml/trait/YamlValue.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2025 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.yaml.trait;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.jspecify.annotations.Nullable;
+import org.openrewrite.Cursor;
+import org.openrewrite.trait.SimpleTraitMatcher;
+import org.openrewrite.trait.Trait;
+import org.openrewrite.yaml.JsonPathMatcher;
+import org.openrewrite.yaml.tree.Yaml;
+
+@AllArgsConstructor
+public class YamlValue implements Trait<Yaml.Mapping.Entry> {
+    @Getter
+    Cursor cursor;
+
+    public String getKey() {
+        return getTree().getKey().getValue();
+    }
+
+    public Yaml.Scalar getKeyAsScalar() {
+        return (Yaml.Scalar) (getTree().getKey());
+    }
+
+    public YamlValue withKey(String newKey) {
+        Yaml.Scalar key = getKeyAsScalar().withValue(newKey);
+        cursor = new Cursor(cursor.getParent(), getTree().withKey(key));
+        return this;
+    }
+
+    public String getValue() {
+        return getValueAsScalar().getValue();
+    }
+
+    public Yaml.Scalar getValueAsScalar() {
+        return (Yaml.Scalar) (getTree().getValue());
+    }
+
+    public YamlValue withValue(String newValue) {
+        Yaml.Scalar value = getValueAsScalar().withValue(newValue);
+        cursor = new Cursor(cursor.getParent(), getTree().withValue(value));
+        return this;
+    }
+
+    public static class Matcher extends SimpleTraitMatcher<YamlValue> {
+        private final JsonPathMatcher jsonPathMatcher;
+
+        public Matcher(String jsonPath) {
+            this.jsonPathMatcher = new JsonPathMatcher(jsonPath);
+        }
+
+        @Override
+        protected @Nullable YamlValue test(Cursor cursor) {
+            if (jsonPathMatcher.matches(cursor) &&
+                cursor.getValue() instanceof Yaml.Mapping.Entry &&
+                ((Yaml.Mapping.Entry) cursor.getValue()).getValue() instanceof Yaml.Scalar) {
+                return new YamlValue(cursor);
+            }
+            return null;
+        }
+    }
+}

rewrite-yaml/src/test/java/org/openrewrite/yaml/trait/YamlValueTest.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2025 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.yaml.trait;
+
+import org.junit.jupiter.api.Test;
+import org.openrewrite.test.RewriteTest;
+
+import static org.openrewrite.yaml.Assertions.yaml;
+
+class YamlValueTest implements RewriteTest {
+
+    @Test
+    void yamlValue() {
+        rewriteRun(
+          spec -> spec.recipe(RewriteTest.toRecipe(() -> new YamlValue.Matcher("$.key").asVisitor(entry ->
+            entry.withKey("key2").withValue("value2").getTree()))),
+          yaml(
+            "key: value",
+            "key2: value2"
+          )
+        );
+    }
+}