fix(yaml): pass depth to sortKeys callback in stringify

yaml/_dumper_state.ts

@@ -433,7 +433,7 @@ export interface DumperStateOptions {
    * if first argument is less than second argument, zero if they're equal
    * and a positive value otherwise.
    */
-  sortKeys?: boolean | ((a: string, b: string) => number);
+  sortKeys?: boolean | ((a: string, b: string, depth: number) => number);
   /** set max line width. (default: 80) */
   lineWidth?: number;
   /**
@@ -467,7 +467,7 @@ export class DumperState {
   arrayIndent: boolean;
   skipInvalid: boolean;
   flowLevel: number;
-  sortKeys: boolean | ((a: string, b: string) => number);
+  sortKeys: boolean | ((a: string, b: string, depth: number) => number);
   lineWidth: number;
   useAnchors: boolean;
   compatMode: boolean;
@@ -667,7 +667,8 @@ export class DumperState {
       keys.sort();
     } else if (typeof this.sortKeys === "function") {
       // Custom sort function
-      keys.sort(this.sortKeys);
+      const sortKeys = this.sortKeys;
+      keys.sort((a, b) => sortKeys(a, b, level));
     } else if (this.sortKeys) {
       // Something is wrong
       throw new TypeError(

yaml/stringify.ts

@@ -55,7 +55,7 @@ export type StringifyOptions = {
    *
    * @default {false}
    */
-  sortKeys?: boolean | ((a: string, b: string) => number);
+  sortKeys?: boolean | ((a: string, b: string, depth: number) => number);
   /**
    * Set max line width.
    *

yaml/stringify_test.ts

@@ -624,6 +624,16 @@ Deno.test("stringify() changes the key order when the sortKeys option is specifi
   );
 });
 
+Deno.test("stringify() passes depth to sortKeys callback", () => {
+  const input = { b: 1, a: 2, nested: { c: 3, d: 4 } };
+  const sortKeys = (a: string, b: string, depth: number) =>
+    depth === 0 ? a.localeCompare(b) : b.localeCompare(a);
+  const expected = ["a: 2", "b: 1", "nested:", "  d: 4", "  c: 3", ""].join(
+    "\n",
+  );
+  assertEquals(stringify(input, { sortKeys }), expected);
+});
+
 Deno.test("stringify() changes line wrap behavior based on lineWidth option", () => {
   const object = {
     message: