change(fastapi): centralize HTTPException

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/asgi.py

@@ -6,8 +6,8 @@ import typing
 
 from urllib.parse import quote_plus
 
-from fastapi import FastAPI, HTTPException, Request
-from fastapi.responses import HTMLResponse, RedirectResponse
+from fastapi import FastAPI, HTTPException, Request, Response
+from fastapi.responses import RedirectResponse
 from fastapi.staticfiles import StaticFiles
 from prometheus_client import multiprocess
 from sqlalchemy import and_, or_
@@ -21,10 +21,11 @@ from aurweb.auth import BasicAuthBackend
 from aurweb.db import get_engine, query
 from aurweb.models import AcceptedTerm, Term
 from aurweb.prometheus import http_api_requests_total, http_requests_total, instrumentator
-from aurweb.routers import accounts, auth, errors, html, packages, rpc, rss, sso, trusted_user
+from aurweb.routers import accounts, auth, html, packages, rpc, rss, sso, trusted_user
+from aurweb.templates import make_context, render_template
 
 # Setup the FastAPI app.
-app = FastAPI(exception_handlers=errors.exceptions)
+app = FastAPI()
 
 # Instrument routes with the prometheus-fastapi-instrumentator
 # library with custom collectors and expose /metrics.
@@ -93,14 +94,15 @@ def child_exit(server, worker):  # pragma: no cover
 
 
 @app.exception_handler(HTTPException)
-async def http_exception_handler(request, exc):
-    """
-    Dirty HTML error page to replace the default JSON error responses.
-    In the future this should use a proper Arch-themed HTML template.
-    """
+async def http_exception_handler(request: Request, exc: HTTPException) \
+        -> Response:
+    """ Handle an HTTPException thrown in a route. """
     phrase = http.HTTPStatus(exc.status_code).phrase
-    return HTMLResponse(f"<h1>{exc.status_code} {phrase}</h1><p>{exc.detail}</p>",
-                        status_code=exc.status_code)
+    context = make_context(request, phrase)
+    context["exc"] = exc
+    context["phrase"] = phrase
+    return render_template(request, "errors/detail.html", context,
+                           exc.status_code)
 
 
 @app.middleware("http")

aurweb/routers/errors.py

@@ -1,21 +0,0 @@
-from http import HTTPStatus
-
-from aurweb.templates import make_context, render_template
-
-
-async def not_found(request, exc):
-    context = make_context(request, "Page Not Found")
-    return render_template(request, "errors/404.html", context,
-                           HTTPStatus.NOT_FOUND)
-
-
-async def service_unavailable(request, exc):
-    context = make_context(request, "Service Unavailable")
-    return render_template(request, "errors/503.html", context,
-                           HTTPStatus.SERVICE_UNAVAILABLE)
-
-# Maps HTTP errors to functions
-exceptions = {
-    404: not_found,
-    503: service_unavailable
-}

templates/errors/404.html

@@ -1,8 +0,0 @@
-{% extends 'partials/layout.html' %}
-
-{% block pageContent %}
-  <div id="error-page" class="box 404">
-    <h2>404 - {% trans %}Page Not Found{% endtrans %}</h2>
-    <p>{% trans %}Sorry, the page you've requested does not exist.{% endtrans %}</p>
-  </div>
-{% endblock %}

templates/errors/503.html

@@ -1,8 +0,0 @@
-{% extends 'partials/layout.html' %}
-
-{% block pageContent %}
-  <div id="error-page" class="box 503">
-    <h2>503 - {% trans %}Service Unavailable{% endtrans %}</h2>
-    <p>{% trans %}Don't panic! This site is down due to maintenance. We will be back soon.{% endtrans %}</p>
-  </div>
-{% endblock %}

templates/errors/detail.html

@@ -0,0 +1,8 @@
+{% extends 'partials/layout.html' %}
+
+{% block pageContent %}
+    <div id="error-page" class="box">
+        <h2>{{ "%d" | format(exc.status_code) }} - {{ phrase }}</h2>
+        <p>{{ exc.detail }}</p>
+    </div>
+{% endblock %}

test/test_asgi.py

@@ -11,6 +11,8 @@ import aurweb.asgi
 import aurweb.config
 import aurweb.redis
 
+from aurweb.testing.requests import Request
+
 
 @pytest.mark.asyncio
 async def test_asgi_startup_session_secret_exception(monkeypatch):
@@ -42,9 +44,11 @@ async def test_asgi_startup_exception(monkeypatch):
 async def test_asgi_http_exception_handler():
     exc = HTTPException(status_code=422, detail="EXCEPTION!")
     phrase = http.HTTPStatus(exc.status_code).phrase
-    response = await aurweb.asgi.http_exception_handler(None, exc)
-    assert response.body.decode() == \
-        f"<h1>{exc.status_code} {phrase}</h1><p>{exc.detail}</p>"
+    response = await aurweb.asgi.http_exception_handler(Request(), exc)
+    assert response.status_code == 422
+    content = response.body.decode()
+    assert f"{exc.status_code} - {phrase}" in content
+    assert "EXCEPTION!" in content
 
 
 @pytest.mark.asyncio