How to test flag evaluation

const client = createFlagFix({
  serverKey: "test-server-key",
  apiHost: "https://api.flagfix.io",
  fetchImpl: async () =>
    new Response(
      JSON.stringify({
        flags: [{ key: "new_checkout", enabled: true, value: null, configurationVersion: 1 }],
        matchedSegments: [],
        configurationVersion: 1,
      }),
      { status: 200, headers: { "content-type": "application/json" } },
    ),
});

Pass fetchImpl so the test never calls the real API. Keep the JSON aligned with the evaluate-all response: flags, matchedSegments, and configurationVersion. The fuller example is Unit testing.

React tests should set lifecycle: false.