fix(env): assign window.__ENV directly instead of queueing it - #6494
Conversation
`<EnvScript>` defaults to Next's `<Script strategy='beforeInteractive'>`, which does not assign `window.__ENV` — it pushes the assignment onto `self.__next_s`. That queue has one consumer, `appBootstrap`, which reads it once and short-circuits to `hydrate()` when empty. The bootstrap chunk's `<script async>` tag sits ~13KB earlier in the document than the env tag, so when that chunk runs first the queue drains empty, nothing drains it again, and `window.__ENV` stays undefined for the life of the document — every `getEnv` read empty until a reload wins the race. `disableNextScript` emits a plain inline `<script>` that assigns unconditionally, so a lost race costs a few milliseconds instead of the session. Also records whether the assignment was still missing at module-init so the residual (module-scope reads in `env-flags`, which freeze what they see) is measured rather than assumed.
|
The latest updates on your projects. Learn more about Vercel for GitHub. |
PR SummaryMedium Risk Overview
Adds Tests now assert rendered markup contains a direct Reviewed by Cursor Bugbot for commit d80e45b. Configure here. |
Greptile SummaryThis PR changes hosted and self-hosted public-environment injection to emit a direct inline
Confidence Score: 5/5The PR appears safe to merge, with no concrete changed-code defects identified. Both deployment paths use the library-supported direct-script option, the repository CSP permits the resulting inline script, and the telemetry addition does not establish a reachable application failure.
|
| Filename | Overview |
|---|---|
| apps/sim/app/_shell/public-env-script.tsx | Hosted environment output now uses the library-supported plain-script mode to assign the global directly. |
| apps/sim/app/layout.tsx | The self-hosted runtime environment component now uses the same direct-assignment mode. |
| apps/sim/lib/core/config/env.ts | Adds a browser-only module-initialization snapshot indicating whether the public environment global was absent. |
| apps/sim/app/_shell/providers/posthog-provider.tsx | Emits telemetry after PostHog initialization when the module-initialization snapshot indicates the environment was missing. |
| apps/sim/app/_shell/public-env-script.test.tsx | Replaces component-implementation assertions with emitted-markup checks for direct assignment and queue avoidance. |
Sequence Diagram
sequenceDiagram
participant Parser as HTML Parser
participant Env as Inline Env Script
participant Boot as Next Bootstrap
participant App as Client App
Parser->>Env: Parse plain script
Env->>Env: Assign window.__ENV directly
Parser->>Boot: Load/execute async bootstrap
Boot->>App: Hydrate application
App->>Env: Read public environment values
Reviews (1): Last reviewed commit: "fix(env): assign window.__ENV directly i..." | Re-trigger Greptile
1 participant
Summary
<EnvScript>defaults to Next's<Script strategy='beforeInteractive'>, which never assignswindow.__ENV— it pushes the assignment ontoself.__next_s.appBootstrapis that queue's only consumer, reads it once, and short-circuits tohydrate()when it's empty.<script async>tag sits ~13KB earlier in the document than the env tag (byte ~790 vs ~13,900), so whenever that chunk runs first the queue drains empty, nothing drains it again, andwindow.__ENVstays undefined for the entire life of the document — everygetEnvread empty until a reload happens to win the race.disableNextScriptemits a plain inline<script>that assigns unconditionally. When it's parsed before the bootstrap chunk it lands strictly earlier than the drain would have; when it isn't, the value arrives a few milliseconds late instead of never.env-flags(isHostedet al) that freeze whatever they see — is measured rather than assumed.This is what killed the workflow editor: with
__ENVabsent,getBaseUrl()throws inside auseMemo(workflow-block.tsx:399for webhook trigger URLs,deploy-modal.tsx:237), taking the route down. The misrouted websocket in the report —wss://www.sim.ai/socket.io/instead ofNEXT_PUBLIC_SOCKET_URL— is the same missing global, and is the cheapest tell that it happened.Render-phase reads are safe once the assignment is unconditional: nothing renders before the RSC payload, which streams from
<body>— after the<head>script. Only module-scope reads lack that ordering, which is what the metric measures.Type of Change
Testing
public-env-script.test.tsxasserts the emitted markup assignswindow.__ENVand contains no__next_spush; verified it fails whendisableNextScriptis removed. Type-check green, lint clean, 974 tests passing across the touched areas.Checklist