test: make sure module is correct

This kills a mutant right away

src/__snapshots__/index.test.tsx.snap

@@ -7,3 +7,10 @@ exports[`Serialization function serializes a JSON+LD script element with data se
   Object {}
 </script>
 `;
+
+exports[`Serialization module matches expectations 1`] = `
+Object {
+  "print": [Function],
+  "test": [Function],
+}
+`;

src/index.test.tsx

@@ -49,3 +49,9 @@ describe("Serialization function", () => {
     expect(ldScriptElement).toMatchSnapshot();
   });
 });
+
+describe("Serialization module", () => {
+  it("matches expectations", () => {
+    expect(serializer).toMatchSnapshot();
+  });
+});