Fix reader (#478)

* fix: numbering reader

* fix: test

docx-core/src/reader/numbering_property.rs

@@ -36,8 +36,9 @@ impl ElementReader for NumberingProperty {
                     let e = XMLElement::from_str(&name.local_name).unwrap();
                     if e == XMLElement::NumberingProperty {
                         if level.is_none() {
-                            return Ok(NumberingProperty::new()
-                                .id(NumberingId::new(id.expect("should id exists"))));
+                            if let Some(id) = id {
+                                return Ok(NumberingProperty::new().id(NumberingId::new(id)));
+                            }
                         }
                         if let Some(id) = id {
                             let np = NumberingProperty::new()

docx-wasm/test/index.test.js

@@ -136,6 +136,12 @@ describe("reader", () => {
     const json = w.readDocx(buffer);
     expect(json).toMatchSnapshot();
   });
+
+  test("should read without num id", () => {
+    const buffer = readFileSync("../fixtures/without_numid/without_numid.docx");
+    const json = w.readDocx(buffer);
+    expect(json).toMatchSnapshot();
+  });
 });
 
 describe("writer", () => {