Fix outstanding frontend_path issues by masenf · Pull Request #6328 · reflex-dev/reflex

masenf · 2026-04-14T20:10:57Z

Summary

Fixes outstanding issues with the frontend_path config option and adds comprehensive integration tests to prevent regressions.

When frontend_path is set (e.g. frontend_path="/app"), the Reflex app is served from a subpath instead of the root. This PR ensures that assets, stylesheets, links, redirects, uploads, on_load events, and 404 pages all work correctly under a configured frontend_path.

Changes

Integration tests (tests/integration/tests_playwright/test_frontend_path.py): Comprehensive playwright tests covering links (static and dynamic routes), redirects (event handler and on_load), assets (local and shared), uploaded files (rx.get_upload_url), CSS url() references, on_load event firing, and 404 pages. Tests are parametrized over dev/prod mode and with/without frontend_path.
Shared asset fix (reflex/assets.py): rx.asset(shared=True) now calls prepend_frontend_path on its return value, matching the existing behavior for local assets.
testing.py: Fix AppHarnessProd to locate 404.html under the frontend_path subdirectory when set, matching real prod deployment behavior.
CI workflow (.github/workflows/integration_app_harness.yml): Run playwright tests in a separate job from other integration tests. The pytest-playwright plugin keeps an asyncio event loop running on the main thread for the session, which is incompatible with pytest-asyncio tests in the same process.

Closes

Supersedes

Add integration tests for frontend path #5712 — The integration tests from that PR are incorporated and expanded here.

Test plan

uv run pytest tests/integration/tests_playwright/test_frontend_path.py -v passes in both dev and prod modes, with and without frontend_path
Existing integration tests still pass: uv run pytest tests/integration --ignore=tests/integration/tests_playwright -v
Playwright tests are isolated from pytest-asyncio tests in CI

* also initialize vite.config.js during compile, in case user has set a different runtime frontend path * remove assetsDir workaround (base handles this case)

Add `prepend_frontend_path` to `rx.Config` to make it easy to handle the contract in current and future APIs. Use `prepend_frontend_path` in: * rx.get_upload_url * rx.asset * vite config * react router config

codspeed-hq · 2026-04-14T20:13:45Z

Merging this PR will not alter performance

✅ 9 untouched benchmarks

_{Comparing masenf/fx-frontend-path (12cfd39) with main (4c53848)}

greptile-apps · 2026-04-14T20:16:16Z

Greptile Summary

This PR fixes frontend_path subpath deployments by introducing a central prepend_frontend_path utility on Config and wiring it through assets, Vite config, React Router basename, static file mounts, and the prod test harness. It also replaces the assetsDir workaround in the Vite template with the proper base option, and separates playwright tests into their own CI job to avoid event-loop conflicts with pytest-asyncio.

Confidence Score: 5/5

Safe to merge — all remaining findings are P2 style/edge-case items that don't affect any realistic user configuration.

Both findings are P2: a commented-out decorator (style/rule violation) and a double-slash edge case in prepend_frontend_path that only triggers when frontend_path="/" — a configuration no user would intentionally set. The core logic is correct, well-refactored, and backed by comprehensive integration tests covering dev/prod × prefix/no-prefix.

packages/reflex-base/src/reflex_base/config.py — the prepend_frontend_path utility could be tightened to strip before the truthiness check.

Important Files Changed

Filename	Overview
packages/reflex-base/src/reflex_base/config.py	Adds `prepend_frontend_path` utility method centralizing all subpath logic; has an edge case where `frontend_path="/"` produces double-slash paths.
packages/reflex-base/src/reflex_base/compiler/templates.py	Replaces the workaround `assetsDir: "{base}assets".slice(1)` with Vite's canonical `base` option — cleaner and more correct for subpath deployments.
reflex/assets.py	Both local and shared `rx.asset` return values now call `prepend_frontend_path`, fixing shared-asset URLs under a configured frontend_path.
reflex/testing.py	`AppHarnessProd` correctly computes the 404 page path and `frontend_url` including the configured prefix using the new `prepend_frontend_path` utility.
reflex/utils/frontend_skeleton.py	Both `_update_react_router_config` (basename) and `_compile_vite_config` (base) now use `prepend_frontend_path`, eliminating duplicated path-assembly logic.
reflex/utils/exec.py	Mount path now uses `prepend_frontend_path`; functionally equivalent because Starlette internally strips trailing slashes from Mount paths.
reflex/app.py	Adds a recompile of the Vite config during the build pipeline so environment-variable-driven `frontend_path` is always picked up; step counter correctly bumped to 8.
tests/integration/tests_playwright/test_frontend_path.py	Comprehensive playwright tests parametrized over dev/prod and with/without prefix; has a commented-out `@pytest.mark.ignore_console_error` decorator that should be removed.
.github/workflows/integration_app_harness.yml	Correctly splits playwright tests into their own job to avoid event-loop conflicts with pytest-asyncio; the non-playwright job keeps its split_index matrix while playwright omits it.
tests/units/test_prerequisites.py	Unit test expectations updated from `assetsDir` to `base` to match the new Vite config format; all three cases (empty, `/test`, `/test/`) are covered.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[frontend_path config\ne.g. '/prefix'] --> B[prepend_frontend_path\nConfig method]

    B --> C[Vite config\nbase: '/prefix/']
    B --> D[React Router\nbasename: '/prefix/']
    B --> E[Starlette Mount\n'/prefix/']
    B --> F[rx.asset local\n'/prefix/image.png']
    B --> G[rx.asset shared\n'/prefix/external/...']
    B --> H[AppHarnessProd\n404 path + frontend_url]

    C --> I[Vite builds assets\nwith correct public URLs]
    D --> J[Client-side nav\nstays under /prefix]
    E --> K[Static file server\nserves from /prefix]
    F & G --> L[Asset URLs\nresolvable by browser]
    H --> M[Test harness\nserves 404.html correctly]

_{Reviews (2): Last reviewed commit: "fix frontend path for shared assets" | Re-trigger Greptile}

playwright uses a session scope fixture which creates an event loop for the session, so subsequent tests using pytest_asyncio fixture cannot start their own loop and fail

include updated test case

masenf · 2026-04-15T18:09:17Z

@greptile-apps re-review this PR

masenf added 3 commits April 13, 2026 16:36

Plumb frontend_path into vite.config.js base option

ede3201

* also initialize vite.config.js during compile, in case user has set a different runtime frontend path * remove assetsDir workaround (base handles this case)

Add test_frontend_path and make sure APIs respect it

bcdc4b1

Add `prepend_frontend_path` to `rx.Config` to make it easy to handle the contract in current and future APIs. Use `prepend_frontend_path` in: * rx.get_upload_url * rx.asset * vite config * react router config

consolidate boilerplate logic in test_frontend_path

caa4fd4

greptile-apps bot reviewed Apr 14, 2026

View reviewed changes

Comment thread tests/integration/tests_playwright/test_frontend_path.py

masenf added 2 commits April 14, 2026 18:09

Always run playwright tests in separate CI job

1b9c8cb

playwright uses a session scope fixture which creates an event loop for the session, so subsequent tests using pytest_asyncio fixture cannot start their own loop and fail

fix frontend path for shared assets

12cfd39

include updated test case

adhami3310 approved these changes Apr 15, 2026

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Fix outstanding frontend_path issues#6328

Fix outstanding frontend_path issues#6328
masenf wants to merge 5 commits intomainfrom
masenf/fx-frontend-path

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Summary

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Test plan

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Merging this PR will not alter performance

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Greptile Summary

Confidence Score: 5/5

Important Files Changed

Flowchart

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masenf commented Apr 15, 2026

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masenf commented Apr 14, 2026 •

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