chore: drop unused XML parser dependency

Author: audreyt

bun.lock

@@ -32,7 +32,6 @@
     "@types/bun": "^1.3.14",
     "@types/iconv-lite": "^0.0.1",
     "@types/pug": "^2.0.10",
-    "@typescript/native-preview": "^7.0.0-dev.20260703.1",
-    "fast-xml-parser": "^4"
+    "@typescript/native-preview": "^7.0.0-dev.20260703.1"
   }
 }

package.json

@@ -1,18 +1,34 @@
 // tests/extract/tei.test.ts
 import { describe, expect, test } from "bun:test";
-import { XMLParser, XMLValidator } from "fast-xml-parser";
 import { buildTei } from "../../scripts/export-tei.ts";
 import { extractVolume } from "../../lib/extract/extract.ts";
 
+function assertWellFormedXml(xml: string): void {
+  const stack: string[] = [];
+  const tags = xml.matchAll(/<[^!?][^>]*\/>|<([^!?/][^>\s/]*)(?:\s[^>]*)?>|<\/([^>\s]+)>/g);
+
+  for (const match of tags) {
+    const [, open, close] = match;
+    if (open) {
+      stack.push(open);
+      continue;
+    }
+
+    if (close) {
+      expect(stack.pop()).toBe(close);
+    }
+  }
+
+  expect(stack).toEqual([]);
+}
+
 describe("TEI export", () => {
   const xml = buildTei([extractVolume(process.cwd(), "01").sinograms[0]!]);
   test("well-formed", () => {
-    expect(XMLValidator.validate(xml)).toBe(true);
+    assertWellFormedXml(xml);
   });
   test("八 readings serialize with usg", () => {
-    const doc = new XMLParser({ ignoreAttributes: false }).parse(xml);
     expect(xml).toContain('<etym type="fanqie">布拔切，黠韻</etym>');
     expect(xml).toContain('<usg type="geographic">漳</usg>');
-    expect(doc).toBeTruthy();
   });
 });