client/web: add barebones vite dev setup

Currently just serving a "Hello world" page when running the web
cli in --dev mode.

Updates tailscale/corp#13775

Co-authored-by: Will Norris <will@tailscale.com>
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>

client/web/vite.config.ts

@@ -0,0 +1,69 @@
+/// <reference types="vitest" />
+import { createLogger, defineConfig } from "vite"
+import rewrite from "vite-plugin-rewrite-all"
+import svgr from "vite-plugin-svgr"
+import paths from "vite-tsconfig-paths"
+
+// Use a custom logger that filters out Vite's logging of server URLs, since
+// they are an attractive nuisance (we run a proxy in front of Vite, and the
+// tailscale web client should be accessed through that).
+// Unfortunately there's no option to disable this logging, so the best we can
+// do it to ignore calls from a specific function.
+const filteringLogger = createLogger(undefined, { allowClearScreen: false })
+const originalInfoLog = filteringLogger.info
+filteringLogger.info = (...args) => {
+  if (new Error("ignored").stack?.includes("printServerUrls")) {
+    return
+  }
+  originalInfoLog.apply(filteringLogger, args)
+}
+
+// https://vitejs.dev/config/
+export default defineConfig({
+  base: "/",
+  plugins: [
+    paths(),
+    svgr(),
+    // By default, the Vite dev server doesn't handle dots
+    // in path names and treats them as static files.
+    // This plugin changes Vite's routing logic to fix this.
+    // See: https://github.com/vitejs/vite/issues/2415
+    rewrite(),
+  ],
+  build: {
+    outDir: "build",
+    sourcemap: true,
+  },
+  esbuild: {
+    logOverride: {
+      // Silence a warning about `this` being undefined in ESM when at the
+      // top-level. The way JSX is transpiled causes this to happen, but it
+      // isn't a problem.
+      // See: https://github.com/vitejs/vite/issues/8644
+      "this-is-undefined-in-esm": "silent",
+    },
+  },
+  server: {
+    // This needs to be 127.0.0.1 instead of localhost, because of how our
+    // Go proxy connects to it.
+    host: "127.0.0.1",
+    // If you change the port, be sure to update the proxy in adminhttp.go too.
+    port: 4000,
+    // Don't proxy the WebSocket connection used for live reloading by running
+    // it on a separate port.
+    hmr: {
+      protocol: "ws",
+      port: 4001,
+    },
+  },
+  test: {
+    exclude: ["**/node_modules/**", "**/dist/**"],
+    testTimeout: 20000,
+    environment: "jsdom",
+    deps: {
+      inline: ["date-fns", /\.wasm\?url$/],
+    },
+  },
+  clearScreen: false,
+  customLogger: filteringLogger,
+})