Add useGafaelfawrUser hook

This hook leverages swr to get a user's data from Gafaelfawr's
/auth/api/v1/user-info endpoint.

New dependencies:

- swr
- unfetch as a polyfill for fetch; this is needed because squared isn't
  inside a Next.js project that bakes the polyfill in for us.

.changeset/bright-sheep-poke.md

@@ -0,0 +1,5 @@
+---
+'@lsst-sqre/squared': minor
+---
+
+Add a useGafaelfawrUser hook.

packages/squared/package.json

@@ -12,8 +12,8 @@
     "dist/**"
   ],
   "scripts": {
-    "build": "tsup src/index.tsx --format esm,cjs --dts --external react",
-    "dev": "tsup src/index.tsx --format esm,cjs --watch --dts --external react",
+    "build": "tsup src/index.ts --format esm,cjs --dts --external react",
+    "dev": "tsup src/index.ts --format esm,cjs --watch --dts --external react",
     "lint": "eslint \"src/**/*.ts*\"",
     "clean": "rm -rf .turbo && rm -rf node_modules && rm -rf dist",
     "storybook": "storybook dev -p 6006",
@@ -25,11 +25,13 @@
   },
   "dependencies": {
     "@fontsource/source-sans-pro": "^4.5.11",
-    "@lsst-sqre/rubin-style-dictionary": "workspace:*",
     "@lsst-sqre/global-css": "workspace:*",
+    "@lsst-sqre/rubin-style-dictionary": "workspace:*",
     "react": "^17.0.2",
     "react-dom": "^17.0.2",
-    "styled-components": "^5.3.6"
+    "styled-components": "^5.3.6",
+    "swr": "^2.2.1",
+    "unfetch": "^5.0.0"
   },
   "devDependencies": {
     "@lsst-sqre/eslint-config": "workspace:*",

packages/squared/src/hooks/useGafaelfawrUser.ts

@@ -0,0 +1,58 @@
+import useSWR, { Fetcher } from 'swr';
+import fetch from 'unfetch';
+
+type GafaelfawrGroup = {
+  name: string;
+  id?: number;
+};
+
+type GafaelfawrApiQuota = {
+  [key: string]: number;
+};
+
+type GafaelfawrNotebookQuota = {
+  cpu: number;
+  memory: number;
+};
+
+type GafaelfawrQuota = {
+  api: GafaelfawrApiQuota;
+  notebook: GafaelfawrNotebookQuota;
+};
+
+type GafaelfawrUser = {
+  username: string;
+  name?: string;
+  email?: string;
+  uid?: number;
+  gid?: number;
+  groups?: GafaelfawrGroup[];
+  quota?: GafaelfawrQuota;
+};
+
+const fetcher: Fetcher<GafaelfawrUser, string> = (url: string) =>
+  fetch(url).then((res) => res.json());
+
+/**
+ * A React hook for getting data from Gafaelfawr's `/auth/user-info` endpoint
+ * and establishing in general whether the user is logged in.
+ */
+const useGafaelfawrUser = () => {
+  const { data, error, isLoading, isValidating } = useSWR(
+    '/auth/api/v1/user-info',
+    fetcher
+  );
+
+  const isLoggedIn = !error && data && data.hasOwnProperty('username');
+
+  return {
+    user: data,
+    isLoading,
+    isValidating,
+    isLoggedIn,
+    error,
+  };
+};
+
+export default useGafaelfawrUser;
+export type { GafaelfawrUser };

packages/squared/src/index.ts

@@ -0,0 +1,8 @@
+/* Components */
+export { Button, type ButtonProps } from './Button';
+
+/* Hooks */
+export {
+  default as useGafaelfawrUser,
+  type GafaelfawrUser,
+} from './hooks/useGafaelfawrUser';