"""Tests for Cache-Control headers on static assets (Sprint 84-B).
Verifies that the _add_static_cache_headers after_request hook:
- Sets long-lived cache headers on CSS and JS responses
- Sets long-lived cache headers on image and font responses
- Does NOT set Cache-Control on HTML page responses
- Only activates for /static/ path prefix
- Does NOT set Cache-Control on non-200 responses
Tests exercise the hook function directly within a test request context to
avoid the need for static files to exist on disk.
"""
import pytest
from flask import Response as FlaskResponse
@pytest.fixture(scope="module")
def flask_app():
"""Import the Flask app and configure for testing."""
from web.app import app
app.config["TESTING"] = True
return app
def _find_hook(flask_app):
"""Return the _add_static_cache_headers after_request hook from the app."""
hooks = flask_app.after_request_funcs.get(None, [])
hook = next(
(f for f in hooks if f.__name__ == "_add_static_cache_headers"),
None,
)
assert hook is not None, "_add_static_cache_headers hook not registered on app"
return hook
def _run_hook(flask_app, path: str, content_type: str, status_code: int = 200) -> str | None:
"""Exercise the hook inside a fake request context; return Cache-Control value."""
hook = _find_hook(flask_app)
with flask_app.test_request_context(path):
response = FlaskResponse(
response=b"fake content",
status=status_code,
content_type=content_type,
)
result = hook(response)
return result.headers.get("Cache-Control")
# ---------------------------------------------------------------------------
# CSS
# ---------------------------------------------------------------------------
def test_static_css_has_cache_control(flask_app):
"""CSS files served from /static/ get a 1-day cache with 7-day SWR."""
cc = _run_hook(flask_app, "/static/style.css", "text/css; charset=utf-8")
assert cc is not None, "Cache-Control header missing on CSS response"
assert "public" in cc
assert "max-age=86400" in cc
assert "stale-while-revalidate=604800" in cc
def test_static_css_no_cache_on_non_200(flask_app):
"""Cache-Control is NOT set on CSS 404 responses."""
cc = _run_hook(flask_app, "/static/missing.css", "text/css", status_code=404)
assert cc is None, "Cache-Control should not be set on non-200 responses"
# ---------------------------------------------------------------------------
# JavaScript
# ---------------------------------------------------------------------------
def test_static_js_has_cache_control(flask_app):
"""JS files served from /static/ get a 1-day cache with 7-day SWR."""
cc = _run_hook(flask_app, "/static/app.js", "application/javascript; charset=utf-8")
assert cc is not None, "Cache-Control header missing on JS response"
assert "public" in cc
assert "max-age=86400" in cc
assert "stale-while-revalidate=604800" in cc
def test_static_js_text_javascript_content_type(flask_app):
"""text/javascript content-type also gets the CSS/JS cache policy."""
cc = _run_hook(flask_app, "/static/app.js", "text/javascript")
assert cc is not None
assert "max-age=86400" in cc
# ---------------------------------------------------------------------------
# Images
# ---------------------------------------------------------------------------
def test_static_image_png_has_cache_control(flask_app):
"""PNG images get a 7-day cache."""
cc = _run_hook(flask_app, "/static/logo.png", "image/png")
assert cc is not None, "Cache-Control header missing on PNG response"
assert "public" in cc
assert "max-age=604800" in cc
def test_static_image_svg_has_cache_control(flask_app):
"""SVG files get the long-lived image cache via content-type."""
cc = _run_hook(flask_app, "/static/icon.svg", "image/svg+xml")
assert cc is not None
assert "max-age=604800" in cc
def test_static_image_extension_fallback(flask_app):
"""PNG files get the cache even if content-type is generic."""
cc = _run_hook(flask_app, "/static/icon.png", "application/octet-stream")
assert cc is not None
assert "max-age=604800" in cc
# ---------------------------------------------------------------------------
# Fonts
# ---------------------------------------------------------------------------
def test_static_font_woff2_by_content_type(flask_app):
"""WOFF2 fonts get the long-lived font cache via content-type."""
cc = _run_hook(flask_app, "/static/font.woff2", "font/woff2")
assert cc is not None, "Cache-Control header missing on WOFF2 response"
assert "public" in cc
assert "max-age=604800" in cc
def test_static_font_woff2_by_path_extension(flask_app):
"""WOFF2 fonts get the cache even if content-type is application/octet-stream."""
cc = _run_hook(flask_app, "/static/font.woff2", "application/octet-stream")
assert cc is not None
assert "max-age=604800" in cc
# ---------------------------------------------------------------------------
# HTML pages — the static hook must be a no-op for HTML
# ---------------------------------------------------------------------------
def test_html_page_no_cache_control(flask_app):
"""HTML responses from non-/static/ paths do NOT get Cache-Control from the static hook."""
cc = _run_hook(flask_app, "/search", "text/html; charset=utf-8")
assert cc is None, (
"HTML page responses must not receive Cache-Control from the static hook"
)
def test_static_html_no_cache_control(flask_app):
"""HTML files under /static/ get no cache header (not CSS/JS/image/font)."""
cc = _run_hook(flask_app, "/static/some.html", "text/html; charset=utf-8")
assert cc is None, "HTML files under /static/ should not be cached by this hook"
# ---------------------------------------------------------------------------
# Non-/static/ paths — hook must be a no-op regardless of content type
# ---------------------------------------------------------------------------
def test_api_json_endpoint_no_static_cache(flask_app):
"""/api/ JSON responses are unaffected by the static cache hook."""
cc = _run_hook(flask_app, "/api/permits", "application/json")
assert cc is None, "/api/ paths must not be touched by the static asset cache hook"
