sync-js-deps assumes host/client_app/ layout (parent.parent walk) — fails ENOENT on flat sm new scaffold

[antosubash]

Summary

simple_module_hosting's sync-js-deps command (used by the new make install target the scaffold ships) hardcodes client_app.parent.parent as the workspace root. That heuristic matches the framework's own repo layout (<repo>/host/client_app/) but is wrong for the flat scaffold sm new produces (<repo>/client_app/), where there's only one parent above client_app/. Result: make install fails with ENOENT reading a package.json two levels above the worktree.

Reproduction

After fixing #126, #127, #128:

$ make install
uv sync
...
Audited 74 packages in 0.07ms
cd client_app && npm install
...
make sync-js-deps
uv run python -m simple_module_hosting sync-js-deps --host-client-app=client_app
INFO: Discovered module: Hello (v0.1.0)
INFO: Discovered module: Settings (v1.0.0)
INFO: Discovered module: Dashboard (v1.0.0)
INFO: Discovered module: Auth (v1.0.0)
INFO: Discovered module: Permissions (v1.0.0)
INFO: Discovered module: Users (v1.0.0)
No module JS dependencies declared.
npm error code ENOENT
npm error syscall open
npm error path /Volumes/ext1/Sandbox/simple_module_chat/package.json
npm error errno -2
npm error enoent Could not read package.json: Error: ENOENT: no such file or directory, open '/Volumes/ext1/Sandbox/simple_module_chat/package.json'
make[1]: *** [sync-js-deps] Error 254
make: *** [install] Error 2

(The actual worktree is /Volumes/ext1/Sandbox/simple_module_chat/confident-lovelace-210ce5/; the heuristic walked up to its parent.)

Root cause

simple_module_hosting/manifest.py:

def repo_root_from_client_app(client_app_dir: Path) -> Path:
    \"\"\"Repo root is two levels above ``host/client_app/``.

    Both ``write_module_pages_manifest`` and the ``sync-js-deps`` CLI
    derive the workspace root from the host's client_app directory.
    Centralized here so the heuristic lives in exactly one place.
    \"\"\"
    return client_app_dir.resolve().parent.parent

Then in host_cli.sync_js_deps:

repo_root = repo_root_from_client_app(host_client_app)
...
result = subprocess.run(cmd, cwd=repo_root, check=False)  # cwd is wrong

npm is invoked from the grandparent of client_app/. In the framework repo that's <repo>/host/client_app/ → <repo>/. In the flat scaffold that's <repo>/client_app/ → <repo>/.., which has no package.json.

Why this matters more than "just an ENOENT"

The npm-workspace shape from the new sm new scaffold requires the root package.json to be at <scaffold_root>/package.json (that's where \"workspaces\": [\"client_app\", \"modules/*\"] is declared). But repo_root_from_client_app is hardcoded to skip past it. So sync-js-deps would fail in any scaffold that uses the flat-with-workspaces shape — even if there were JS deps to install.

Right now the fix that lets npm run dev work end-to-end (verified locally) is the workspace structure itself: with a root package.json declaring workspaces, vite can walk up from .venv/.../site-packages/<mod>/*.tsx and find the workspace root node_modules. So sync-js-deps may not even be load-bearing for the bundled modules. But the broken heuristic still kills make install.

Suggested fix

Replace the hardcoded walk with a proper search. Walk up from client_app/ looking for the first ancestor that has a package.json declaring workspaces (or, failing that, the first ancestor with any package.json):

def repo_root_from_client_app(client_app_dir: Path) -> Path:
    here = client_app_dir.resolve()
    for parent in (here.parent, *here.parents):
        pkg = parent / \"package.json\"
        if pkg.is_file():
            try:
                data = json.loads(pkg.read_text())
            except json.JSONDecodeError:
                continue
            if \"workspaces\" in data:
                return parent
    # Fallback: keep current behavior so the framework repo still works.
    return here.parent.parent

That handles both layouts correctly:

• Framework repo: host/client_app/ → walks up to repo root with workspaces.
• Flat sm new scaffold: client_app/ → walks up one level to scaffold root with workspaces.

Workaround

Comment out sync-js-deps from the Makefile's install target, or run make install with make sync-js-deps -i to ignore the failure. The @simple-module-py/ui@0.0.8 package brings the bundled modules' transitive deps anyway, so sync-js-deps finding nothing to install (No module JS dependencies declared.) is fine — the failure is purely in the npm-cwd, not in the dep resolution.

Related

• sm new should scaffold host + a working sample module in a uv/npm workspace, matching the framework repo's own layout #117 — workspace-shaped scaffold; this issue is what you hit because the new scaffold is workspace-shaped, but the framework code wasn't updated to match.
• Module wheels declare empty 'dependencies' but their .tsx imports lucide-react/sonner directly; Makefile never runs sm host sync-js-deps #116 — original sync-js-deps issue (now mostly moot, but this would unblock its happy path too).

Environment

• simple_module_hosting 0.0.8
• simple_module_cli 0.0.8
• The new flat-with-workspaces sm new scaffold output

[antosubash]

Fixed in #130.

[antosubash]

Verified in 0.0.10. New scaffold layout puts client_app/ under host/, so client_app.parent.parent correctly lands on the workspace root. Makefile invokes cd host && python -m simple_module_hosting sync-js-deps. Clean run:

Installing module JS deps:
  lucide-react@^1.8.0
  sonner@^2.0.0
added 1 package in 352ms