Add plain HTML frontend served by the API at /app

README.md

@@ -131,6 +131,20 @@ Get-Content env.dev.example | ForEach-Object {
 Start-Process "http://localhost:8080"
 ```
 
+### Plain HTML frontend (no Node needed)
+
+`web/index.html` is a single-file frontend with no build step. The API serves
+it at `/app`, so it needs no CORS setup and no second terminal. After step 5:
+
+```powershell
+Start-Process "http://localhost:8000/app"
+```
+
+It covers import (preview, column types, new table or T&E table, skip or
+replace duplicates), migrated files with a row viewer and delete, T&E table
+row counts, and the deletion log. If the API runs with `API_KEY` set, enter
+the same key with the key button in the page header.
+
 ---
 
 ## API Surface

api/main.py

@@ -9,11 +9,13 @@
 
 import logging
 from contextlib import asynccontextmanager
+from pathlib import Path
 
 import psycopg2.pool
 from fastapi import FastAPI, Request
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse
+from fastapi.staticfiles import StaticFiles
 
 from api import db
 from api.config import settings
@@ -72,6 +74,12 @@ async def lifespan(app: FastAPI):
 app.include_router(te_routes.router)
 app.include_router(audit_routes.router)
 
+# Plain HTML frontend (web/index.html), served same-origin at /app so it needs
+# no CORS setup. Skipped when web/ isn't shipped (e.g. an API-only image).
+WEB_DIR = Path(__file__).resolve().parent.parent / "web"
+if WEB_DIR.is_dir():
+    app.mount("/app", StaticFiles(directory=WEB_DIR, html=True), name="web")
+
 
 @app.exception_handler(psycopg2.pool.PoolError)
 def pool_exhausted_handler(request: Request, exc: psycopg2.pool.PoolError) -> JSONResponse:

tests/test_api_unit.py

@@ -153,3 +153,14 @@ def test_identifiers_are_never_string_formatted(self):
                     offenders.append(f"{path.name}:{node.lineno}")
         self.assertEqual(offenders, [],
                          f"execute() called with an f-string at {offenders}")
+
+
+@pytest.mark.unit
+class WebFrontend(unittest.TestCase):
+    """The plain HTML frontend in web/ is served same-origin at /app."""
+
+    def test_app_serves_index_html(self):
+        r = client.get("/app/")
+        self.assertEqual(r.status_code, 200)
+        self.assertIn("text/html", r.headers["content-type"])
+        self.assertIn("<title>CSV Migrator</title>", r.text)