tern-node

The napi binding between Deno/Node.js and tern-core. JS code (the reconciler in packages/core) constructs a scene with create_node / NodeHandle, and a TuiRenderer owns the terminal lifecycle and paint loop.

Building

The binding is a Rust cdylib compiled by napi-rs v3 (napi + napi-derive), built with @napi-rs/cli:

cd src/bindings/tern-node
npm install              # fetches @napi-rs/cli
npm run build            # release profile (default): napi build --platform --release && node fix-dts.mjs
npm run build:debug      # debug profile, fast local iteration: napi build --platform && node fix-dts.mjs

This produces, in this directory:

• index.js — the JS loader that requires the platform addon
• index.d.ts — TypeScript declarations for the exported surface
• tern-node.<platform>-<arch>.node — the native addon (e.g. tern-node.darwin-arm64.node on macOS arm64)

API surface

class TuiRenderer {
  constructor(options?: { exit_on_ctrl_c?: boolean });
  root(): NodeHandle;
  poll_events(timeout_ms: number): KeyEvent[]; // { name, char?, ctrl, alt, shift }
  render(): void;
  destroy(): void;
  get destroyed(): boolean;
}

function create_node(type: "box" | "text", props?: Record<string, unknown>): NodeHandle;

class NodeHandle {
  add_child(child: NodeHandle): NodeHandle;
  remove(): boolean;
  set_props(props: Record<string, unknown>): void;
  set_prop(key: string, value: unknown): void; // single-key (style keys merge)
}

TuiRenderer enters raw mode + the alternate screen on construction and restores the terminal on destroy() (or automatically on Ctrl+C when exit_on_ctrl_c: true).

Smoke test

Deno-first (the primary runtime target): the addon is loaded through node:module createRequire, which Deno 2.x supports for Node-API addons with --allow-all (includes --allow-ffi). If Deno addon loading fails, the smoke falls back to node and prints the limitation.

# inside this directory (built addon required):
printf 'q' | script -q /dev/null deno run --allow-all smoke.mjs   # PTY smoke: renders, quits on 'q'
# from the repo root:
printf 'q' | script -q /dev/null deno run --allow-all src/bindings/tern-node/smoke.mjs

Exit code 0 means: addon loaded, typeof TuiRenderer === 'function', the scene rendered, and the piped 'q' was received as a key event.