Pin es2020 browser target for IIFE/ESM bundles (fix streamed chat turn) → 0.5.2

[brentrager]

Problem

The deployed <script src=\"chat-widget.global.js\"> embed could fail on the streamed chat turn: it connects + creates a session (greeting shows, status "ready" — single-await calls work) but throws "Connection issue" on send_message, while the ESM build of the same version works. The raw operator protocol, src/conversation.ts, and the protocol client are all correct — it's a build-output issue isolated to the streaming path (MessageTurn async-iterator / for await).

Root cause (build setting)

tsdown derived a Node transpile target (target: node22.0.0) from the package engines for all outputs — including the browser <script> IIFE globals. A Node target is wrong for a browser embed and is exactly the class of setting that can silently downlevel the smooth-operator client's async generators / for await over the streaming MessageTurn (Symbol.asyncIterator) into regenerator/helper shims, mangling the stream in stricter engines. The ESM build keeps the client external (the host supplies it), so it's unaffected — which is why ESM worked and the IIFE didn't.

Fix

Pin an explicit es2020 browser target on all three outputs (ESM + both IIFE globals), so native async iteration is preserved and the IIFE global bundle stays byte-faithful to the ESM build on the streaming path. The bundle keeps native Symbol.asyncIterator / for await (verified in the emitted output — no regenerator/helper shims).

Verification

• Built bundle streams a full grounded turn against the live prod operator (wss://ai.smoo.ai/ws, agent 2590dfd6-…, Origin spoofed to https://smoo.ai) in headless Chromium — multiple runs, full multi-sentence grounded reply renders.
• pnpm check (typecheck + 30 unit tests + build) green.
• Added two regression specs:
  • e2e/repro-stream-mock.spec.ts — CI-safe; drives the real shadow-DOM UI through a deterministic mock WS replaying the operator frame sequence (immediate_response{202} → stream_token×N → eventual_response).
  • e2e/repro-prod.spec.ts — gated on SMOOTH_AGENT_PROD_E2E=1; hits live prod.

Publish version

0.5.2 (patch; changeset included).

🤖 Generated with Claude Code

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