test(NODE-7165): migrate integration/bson-decimal128 tests

test/integration/bson-decimal128/decimal128.test.ts

@@ -0,0 +1,31 @@
+import { expect } from 'chai';
+
+import { type Collection, Decimal128, type MongoClient } from '../../../src';
+
+describe('Decimal128', function () {
+  let client: MongoClient;
+  let collection: Collection;
+
+  beforeEach(async function () {
+    client = this.configuration.newClient();
+    collection = client.db('decimal128').collection('decimal128');
+  });
+
+  afterEach(async function () {
+    await client.close();
+  });
+
+  it('should correctly insert decimal128 value', async function () {
+    const object = {
+      id: 1,
+      value: Decimal128.fromString('1.28')
+    };
+    await collection.insertOne(object);
+    const doc = await collection.findOne({
+      id: 1
+    });
+
+    expect(doc.value).to.be.instanceof(Decimal128);
+    expect(doc.value.toString()).to.equal('1.28');
+  });
+});