ci(react-sdk): add contract tests by joker23 · Pull Request #1160 · launchdarkly/js-core

joker23 · 2026-03-06T17:57:27Z

This PR will add the initial contract tests for react sdk

Current limitation of the contract tests is that they are basically just testing the underlying browser sdk. We will iterate these tests to be more idiomatic to the react SDK.

Note

Medium Risk
Moderate risk due to new CI execution steps (Playwright install, background services, harness integration) that can introduce flakiness or longer runtimes, though runtime SDK code is largely untouched.

Overview
Adds React SDK contract tests by introducing a new packages/sdk/react/contract-tests workspace that runs a Next.js “entity” controlled via a WebSocket bridge, executes core SDK commands (flag evaluation, identify/track/flush), and supports hook callbacks for test verification.

Updates the React GitHub Actions workflow to install/build the adapter + contract-test workspace, install Playwright Chromium, start adapter/entity/browser processes, run the shared contract-tests action with a suppressions.txt, and always clean up background services. Also adds React contract-test-specific ESLint/TS config and bumps React SDK dev typings to React 19 (@types/react, @types/react-dom).

^{Written by Cursor Bugbot for commit c6c4040. This will update automatically on new commits. Configure here.}

github-actions · 2026-03-06T17:58:55Z

@launchdarkly/js-sdk-common size report
This is the brotli compressed size of the ESM build.
Compressed size: 25566 bytes
Compressed size limit: 26000
Uncompressed size: 125383 bytes

github-actions · 2026-03-06T17:59:14Z

@launchdarkly/browser size report
This is the brotli compressed size of the ESM build.
Compressed size: 172130 bytes
Compressed size limit: 200000
Uncompressed size: 800872 bytes

github-actions · 2026-03-06T17:59:15Z

@launchdarkly/js-client-sdk size report
This is the brotli compressed size of the ESM build.
Compressed size: 24212 bytes
Compressed size limit: 25000
Uncompressed size: 83755 bytes

github-actions · 2026-03-06T17:59:21Z

@launchdarkly/js-client-sdk-common size report
This is the brotli compressed size of the ESM build.
Compressed size: 21281 bytes
Compressed size limit: 24000
Uncompressed size: 110213 bytes

joker23 · 2026-03-09T18:15:41Z

@cursor review

cursor

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, have a team admin enable autofix in the Cursor dashboard.}

cursor · 2026-03-09T18:19:32Z

packages/sdk/react/contract-tests/app/ClientRoot.tsx

+            record.client.close();
+          }
+          return prev.filter((r) => r.id !== id);
+        });


Side effect in state updater causes double-close

Medium Severity

The onDeleteClient callback calls record.client.close() inside the setClients state updater function. This is a side effect in what React expects to be a pure function. Since the contract tests run via next dev (React Strict Mode is enabled by default), React will double-invoke the updater function during development, causing close() to be called twice on the same client. The side effect (close()) needs to be performed outside the state updater.

packages/sdk/react/contract-tests/app/ClientRoot.tsx

joker23 · 2026-03-09T19:02:43Z

@cursor review

joker23 · 2026-03-09T19:11:37Z

packages/sdk/react/contract-tests/app/ClientEntity.ts

+
+// NOTE: we can make this more idiomatic to React by creating a useCommand hook and reading return values from
+// a rendered component. But for now, this is just a simple way to get the tests running.
+export async function doCommand(client: LDReactClient, params: CommandParams): Promise<unknown> {


Right now this is more or less the same as the browser contract test

joker23 · 2026-03-09T19:12:34Z

packages/sdk/react/contract-tests/app/CommandParams.ts

@@ -0,0 +1,176 @@
+import { LDContext, LDEvaluationReason } from '@launchdarkly/react-sdk';


Right now this is more or less the same as the browser contract test

joker23 · 2026-03-09T19:12:52Z

packages/sdk/react/contract-tests/app/ConfigParams.ts

@@ -0,0 +1,90 @@
+import { LDContext } from '@launchdarkly/react-sdk';
