fix(yaml): speciously restrictive type for stringify()

yaml/stringify.ts

@@ -15,8 +15,8 @@ export type DumpOptions = DumperStateOptions;
  * You can disable exceptions by setting the skipInvalid option to true.
  */
 export function stringify(
-  obj: Record<string, unknown>,
+  data: unknown,
   options?: DumpOptions,
 ): string {
-  return dump(obj, options);
+  return dump(data, options);
 }

yaml/stringify_test.ts

@@ -45,6 +45,50 @@ binary: !<tag:yaml.org,2002:binary> SGVsbG8=
   },
 });
 
+Deno.test({
+  name: "arrays can be stringified directly",
+  fn() {
+    const array = [1, 2, 3]
+
+    const expected = "- 1\n- 2\n- 3\n";
+
+    assertEquals(stringify(array), expected);
+  },
+});
+
+Deno.test({
+  name: "strings can be stringified directly",
+  fn() {
+    const string = 'Hello world';
+
+    const expected = 'Hello world\n';
+
+    assertEquals(stringify(string), expected);
+  },
+});
+
+Deno.test({
+  name: "numbers can be stringified directly",
+  fn() {
+    const number = 1.01;
+
+    const expected = "1.01\n";
+
+    assertEquals(stringify(number), expected);
+  },
+});
+
+Deno.test({
+  name: "booleans can be stringified directly",
+  fn() {
+    const boolean = true;
+
+    const expected = "true\n";
+
+    assertEquals(stringify(boolean), expected);
+  },
+});
+
 Deno.test({
   name: "stringify() throws with `!!js/*` yaml types with default schemas",
   fn() {