add test for IdGenerator

javascript/test/IdGeneratorTest.ts

@@ -0,0 +1,17 @@
+import assert from "node:assert"
+import {IdGenerator} from "../src/index.js"
+
+describe('IdGenerator', () => {
+  it('generates uuids', () => {
+    const generator = IdGenerator.uuid()
+    const result = generator()
+    assert.equal(result.length, 36)
+  });
+
+  it('increments ids', () => {
+    const generator = IdGenerator.incrementing()
+    assert.equal(generator(), '0')
+    assert.equal(generator(), '1')
+    assert.equal(generator(), '2')
+  })
+})