Problem

Bundling web-tree-sitter@0.26.x for the browser fails because two await import() calls in environment-guarded branches are statically discoverable by bundlers:

• await import("fs/promises") at web-tree-sitter.js:1487 (inside Language.load — guarded by globalThis.process?.versions.node)
• await import("module") at web-tree-sitter.js:1527 (inside the emscripten module init — guarded by ENVIRONMENT_IS_NODE)

Even though those branches never execute in a browser, the bundler tries to resolve the specifiers at build time and errors out.

Minimal repro

package.json:

{
  "name": "wts-bundle-repro",
  "private": true,
  "type": "module",
  "scripts": {
    "repro": "esbuild --bundle --platform=browser --format=esm --outfile=out.js entry.js"
  },
  "dependencies": {
    "esbuild": "^0.27.0",
    "web-tree-sitter": "^0.26.6"
  }
}

entry.js:

import 'web-tree-sitter';

Run npm install && npm run repro:

✘ [ERROR] Could not resolve "fs/promises"

    node_modules/web-tree-sitter/web-tree-sitter.js:1487:31:
      1487 │       const fs2 = await import("fs/promises");
           ╵                                ~~~~~~~~~~~~~

  The package "fs/promises" wasn't found on the file system but is built into node. Are you trying to bundle for node? You can use "--platform=node" to do that, which will remove this error.

✘ [ERROR] Could not resolve "module"

    node_modules/web-tree-sitter/web-tree-sitter.js:1527:43:
      1527 │     const { createRequire } = await import("module");
           ╵                                            ~~~~~~~~

  The package "module" wasn't found on the file system but is built into node. Are you trying to bundle for node? You can use "--platform=node" to do that, which will remove this error.

2 errors

Tested with web-tree-sitter@0.26.8 and esbuild@0.27.7. Other bundlers (vite, webpack) likely fail similarly — see historical reports #466, #681, #1121.

Workaround

Mark them external:

esbuild --bundle --platform=browser --format=esm \
  --external:fs/promises --external:module --outfile=out.js entry.js

This succeeds (bundle ~150KB) and is safe at runtime: the imports stay as bare specifiers in the output but are guarded by Node-only checks that never fire in a browser.

Suggested fixes (any of)

1. Add a "browser" condition in package.json#exports pointing at a Node-stripped entry.
2. Add a top-level "browser" field mapping fs/promises and module to false.
3. Move the Node-only loader into a separate file imported through a specifier that bundlers can't statically resolve (e.g. await import(/* @vite-ignore */ nodeOnlyPath) with nodeOnlyPath a runtime-built string).

Environment

• web-tree-sitter 0.26.8
• esbuild 0.27.7
• macOS 24.6.0 (also reproduces on Linux)