refactor: add type tests

Author: John Doe

packages/utils/src/lib/user-timing-extensibility-api.type.unit.test.ts

@@ -0,0 +1,44 @@
+import { describe, expectTypeOf, it } from 'vitest';
+import type {
+  DevToolsColor,
+  MarkerPayload,
+  TrackEntryPayload,
+  WithDevToolsPayload,
+  WithErrorColor,
+} from './user-timing-extensibility-api.type.js';
+
+describe('TrackEntryPayload', () => {
+  it('TrackEntryPayload extends ExtensionTrackBase and TrackMeta', () => {
+    expectTypeOf<{
+      dataType?: 'track-entry';
+      track: string;
+    }>().toMatchTypeOf<TrackEntryPayload>();
+  });
+});
+
+describe('MarkerPayload', () => {
+  it('MarkerPayload extends ExtensionTrackBase with required dataType', () => {
+    expectTypeOf<{
+      dataType: 'marker';
+    }>().toMatchTypeOf<MarkerPayload>();
+  });
+});
+
+describe('WithErrorColor', () => {
+  it('WithErrorColor removes optional color and adds required error color', () => {
+    expectTypeOf<{
+      color: 'error';
+      otherProp: string;
+    }>().toMatchTypeOf<
+      WithErrorColor<{ color?: DevToolsColor; otherProp: string }>
+    >();
+  });
+});
+
+describe('WithDevToolsPayload', () => {
+  it('WithDevToolsPayload makes devtools optional', () => {
+    expectTypeOf<{
+      devtools?: TrackEntryPayload;
+    }>().toMatchTypeOf<WithDevToolsPayload<TrackEntryPayload>>();
+  });
+});