Pull the static file server into the CRA proxy as well

With this, the outer npm-project is finally obsolete.
See the updated `README` for how to use it and the proxy server.
I abstained from restructuring the project any further
to keep the PR focused, but a PR that will do nothing
but move things around is in the pipeline.

Note, this is based on opencast#394.

.github/dependabot.yml

@@ -8,14 +8,6 @@ updates:
       interval: monthly
 
   # Javascript
-  - package-ecosystem: npm
-    directory: "/"
-    schedule:
-      interval: monthly
-      time: "04:00"
-    open-pull-requests-limit: 15
-    labels:
-      - dependencies
   - package-ecosystem: npm
     directory: "/app"
     schedule:

.github/workflows/test.yml

@@ -18,9 +18,6 @@ jobs:
         with:
           node-version: 20
 
-      - name: download tooling dependencies
-        run: npm ci
-
       - name: download dependencies
         working-directory: ./app
         run: npm ci

README.md

@@ -13,10 +13,8 @@ To get a local copy of the admin UI to test or develop on, you can do the follow
 git clone [email protected]:opencast/opencast-admin-interface.git opencast-admin-interface-demo
 cd opencast-admin-interface-demo
 git switch my-branch  # or otherwise check out, pull, merge, etc. whatever branch you want to test/hack on
-npm ci
 cd app
 npm ci
-cd ..
 ```
 
 You can now run a local instance of the UI by saying
@@ -25,17 +23,29 @@ You can now run a local instance of the UI by saying
 npm start
 ```
 
-This runs a static file server in the background replying mock data to the various requests
+This runs a development server at `http://localhost:3000`, serving a development build
+of the admin UI, and automatically opens a browser tab pointed to it.
+The build and the browser tab should automatically refresh on every change you make
+to the codebase.
+By default, this server also replies mock data to the various requests
 the UI would normally send to the Opencast backend.
-It also runs an autoreloading development server delivering the admin UI itself,
-and automatically open a browser tab pointing to it.
 
-Not all functionality of the admin UI works in this mode. If you need to test with real data,
-or need the ability to change it, you can rely on the proxy functionality of said development server,
-instead of running the static file server. Run:
+Not all functionality of the admin UI works in this mode. If you need to test
+with real data, or need the ability to change it, you can rely on the
+proxy functionality of said development server, instead of running the static file server. Run:
 
 ```sh
-PROXY_TARGET=https://develop.opencast.org npm run client
+PROXY=1 npm start
+```
+
+This assumes you have an Opencast instance running at `http://localhost:8080`
+to which the development server will then proxy all the backend request,
+authenticating them as user `admin` with password `opencast`.
+
+If you want to work with a different Opencast and/or user, you can change the command thusly:
+
+```sh
+PROXY_TARGET=https://develop.opencast.org npm start
 ```
 
 Here, `PROXY_TARGET` is the target URL of the Opencast instance you want to test against.
@@ -50,22 +60,10 @@ in the `PROXY_AUTH` variable in the format `user:password`, as in
 PROXY_TARGET=http://localhost:8080 PROXY_AUTH=jdoe:aligator3 npm run client
 ```
 
-### Ports
-
-By default, the development server runs on port `3000`, and the static server on port `5000`.
-If you need to change these ports, you have to do the following:
-
-```sh
-PORT=5001 npm run server
-```
-
-This runs the static server only, serving assets under `http://localhost:5001`. Now, in a second terminal, run:
-
-```sh
-PORT=3001 PROXY_TARGET=http://localhost:5001 npm run client
-```
+Note that `PROXY=1` is not required if you specify either `PROXY_TARGET` or `PROXY_AUTH`.
 
-This runs the development server on port `3001` and tells it about the alternative file server location.
+Similarly, if you want to change the port the development server itself runs at,
+you can specify an alternative port in the `PORT` environment variable.
 
 How to cut a release for Opencast
 ---------------------------------

app/src/setupProxy.js

@@ -1,21 +1,40 @@
 const { createProxyMiddleware } = require("http-proxy-middleware");
+const express = require("express");
+const path = require("path");
 
 module.exports = app => {
-    app.use(
-        [
-            "/acl-manager",
-            "/admin-ng",
-            "/api",
-            "/info",
-            "/services",
-            "/staticfiles",
-            "/sysinfo",
-            "/ui",
-        ],
-        createProxyMiddleware({
-            target: process.env.PROXY_TARGET || "http://localhost:8080",
-            changeOrigin: true,
-            auth: process.env.PROXY_AUTH || "admin:opencast",
-        }),
-    );
+    app.use([
+        "/acl-manager",
+        "/admin-ng",
+        "/api",
+        "/info",
+        "/services",
+        "/staticfiles",
+        "/sysinfo",
+        "/ui",
+    ], middleware);
 };
+
+const middleware = process.env.PROXY || process.env.PROXY_TARGET || process.env.PROXY_AUTH
+    ? createProxyMiddleware({
+        target: process.env.PROXY_TARGET || "http://localhost:8080",
+        changeOrigin: true,
+        auth: process.env.PROXY_AUTH || "admin:opencast",
+    })
+    : (req, res, next) => {
+        if (req.method === "POST") {
+            res.status(201);
+        }
+
+        req.url = `/${req.method}${req.originalUrl}`;
+
+        if (req.method !== "GET") {
+            req.originalMethod = req.method;
+            req.method = "GET";
+            setTimeout(testFiles, 1000, req, res, next);
+        } else {
+            testFiles(req, res, next);
+        }
+    };
+
+const testFiles = express.static(`${__dirname}/../../test/app`);