fix(app): normalize subpath imports to install base npm package

[BABTUNA]

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Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
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Changes To Core Features:

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Description

Fixes frontend package installation when component import keys include package subpaths.

Before this change, _get_frontend_packages attempted to install subpath keys directly (for example
eact-map-gl/maplibre), which is not an installable npm package name.

This patch adds package-name normalization in App._get_frontend_packages:

• Converts unscoped subpaths like
  eact-map-gl/maplibre to
  eact-map-gl.
• Converts scoped subpaths like @scope/pkg/subpath to @scope/pkg.
• Preserves pinned version info when present.

Tests

Added regression test:

• est_get_frontend_packages_maps_subpath_imports_to_installable_package_names

Validation run:

• uv run pytest tests/units/test_app.py -k "maps_subpath_imports_to_installable_package_names" -q
• uv run ruff check reflex/app.py tests/units/test_app.py

Closes #6234

[greptile-apps]

Greptile Summary

This PR fixes frontend package installation for components that use npm subpath imports (e.g. react-map-gl/maplibre) by extracting a _get_frontend_package_name helper that normalises both unscoped and scoped subpaths down to their installable base package name.

• P1 regression: URL-based import keys (CDN-style imports starting with https) are not excluded early; format_library_name returns them unchanged but the subsequent .split("/", maxsplit=1)[0] reduces them to "https:", which is passed to install_frontend_packages instead of the original URL.
• P2 edge case: imports combining a version pin and a subpath (e.g. react-map-gl@1.0.0/maplibre) hit the if package_name == library_name: return import_name short-circuit because format_library_name already strips @1.0.0/maplibre, so the full subpath string is returned unchanged.

Confidence Score: 3/5

Not safe to merge as-is — introduces a regression for https:// URL imports that was absent before this change.

The P1 finding is a concrete behavioural regression: any component whose import key starts with https:// will now attempt to install a package named 'https:' instead of the original URL. This replaces working behaviour with a silent mis-install. The P2 versioned-subpath edge case is lower risk but also untested.

reflex/app.py — _get_frontend_package_name needs an early-return for https:// URL imports and a fix for the versioned+subpath case.

Important Files Changed

Filename	Overview
reflex/app.py	Adds _get_frontend_package_name static method for subpath normalization; regression for https:// URL imports and edge-case bug with versioned+subpath imports.
tests/units/test_app.py	New regression test covers the primary unscoped and scoped subpath cases; missing coverage for versioned+subpath and https:// URL imports.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["import_name"] --> B{"empty or starts\nwith /, $/, .?"}
    B -- yes --> C["return None"]
    B -- no --> D["format_library_name(import_name)\n→ strips @version suffix"]
    D --> E{"starts with '@'?\n(scoped package)"}
    E -- yes --> F["Extract @scope/pkg\nfrom @scope/pkg/subpath"]
    E -- no --> G["Split on first '/'\n→ base package name"]
    F --> H{"package_name\n== library_name?"}
    G --> H
    H -- yes --> I["return import_name\n⚠️ BUG if versioned+subpath\n⚠️ BUG if https:// URL"]
    H -- no --> J{"import_name has\npinned version?"}
    J -- yes --> K["return package_name@version"]
    J -- no --> L["return package_name"]

Loading

_{Reviews (1): Last reviewed commit: "fix(app): install base npm package for s..." | Re-trigger Greptile}

[greptile-apps]

https:// URL imports mangled to "https:"

format_library_name short-circuits for https://… URLs and returns the full URL unchanged. That URL then falls through to the unscoped branch where .split("/", maxsplit=1)[0] produces "https:", which is returned as the package name and later passed to install_frontend_packages.

The original code passed such URL imports through intact; this PR introduces a regression for any component whose import key starts with https:// (e.g. Skypack CDN imports). An early-return for https:// in _get_frontend_package_name would restore the previous behaviour:

if import_name == "" or any(
    import_name.startswith(prefix) for prefix in ("/", "$/", ".", "https://")
):
    return None

[greptile-apps]

Versioned + subpath imports returned unchanged

When an import carries both a version pin and a subpath, e.g. react-map-gl@1.0.0/maplibre, format.format_library_name strips @1.0.0/maplibre entirely via rpartition("@"), yielding library_name = "react-map-gl". At that point package_name (also "react-map-gl") equals library_name, so the guard if package_name == library_name: return import_name fires and returns "react-map-gl@1.0.0/maplibre" — the original subpath-containing string — defeating the fix.

The condition is meant to short-circuit when there is no subpath to strip, but it does not account for format_library_name having already consumed the subpath as part of the version segment. Checking whether the original import_name contains a / after the version separator would close the gap.

[BABTUNA]

Addressed both review points in 7516516:

• Fixed URL import regression: _get_frontend_package_name now preserves https:///http:// imports instead of mangling to https:.
• Fixed versioned+subpath normalization: imports like react-map-gl@1.0.0/maplibre and @scope/pkg@2.0.0/subpath now normalize to react-map-gl@1.0.0 and @scope/pkg@2.0.0.

Added regression tests:

• test_get_frontend_packages_keeps_https_imports_unchanged
• test_get_frontend_packages_maps_versioned_subpath_imports_to_pinned_base

Validation:

• uv run pytest tests/units/test_app.py -k "maps_subpath_imports_to_installable_package_names or keeps_https_imports_unchanged or maps_versioned_subpath_imports_to_pinned_base" -q
• uv run ruff check reflex/app.py tests/units/test_app.py