yaml() assertions (#6459)

Author: greg-at-moderne

rewrite-javascript/rewrite/src/yaml/assertions.ts

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2025 the original author or authors.
+ * <p>
+ * Licensed under the Moderne Source Available License (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://docs.moderne.io/licensing/moderne-source-available-license
+ * <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.
+ */
+import {AfterRecipeText, dedentAfter, SourceSpec} from "../test";
+import {YamlParser} from "./parser";
+import {Yaml} from "./tree";
+
+export function yaml(before: string | null, after?: AfterRecipeText): SourceSpec<Yaml.Documents> {
+    return {
+        kind: Yaml.Kind.Documents,
+        before: before,
+        after: dedentAfter(after),
+        ext: 'yaml',
+        parser: () => new YamlParser()
+    };
+}

rewrite-javascript/rewrite/src/yaml/index.ts

@@ -13,9 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+export * from "./assertions";
+export * from "./parser";
 export * from "./tree";
 export * from "./visitor";
-export * from "./parser";
 
 import "./print";
 import "./rpc";

rewrite-javascript/rewrite/test/yaml/parser.test.ts

@@ -13,8 +13,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {isDocuments, isMapping, isScalar, isSequence, Yaml, YamlParser} from "../../src/yaml";
+import {isDocuments, isMapping, isScalar, isSequence, Yaml, yaml, YamlParser} from "../../src/yaml";
 import {printer} from "../../src";
+import {RecipeSpec} from "../../src/test";
 
 async function parseAndPrint(yaml: string): Promise<string> {
     const parser = new YamlParser();
@@ -323,3 +324,12 @@ block:
         expect(block.openingBracePrefix).toBeUndefined();
     });
 });
+
+describe('yaml assertion helper', () => {
+    const spec = new RecipeSpec();
+
+    test('simple mapping', () =>
+        spec.rewriteRun(
+            yaml('key: value')
+        ));
+});