feat(auth): add auth module

.gitignore

@@ -4,5 +4,6 @@
 /test-results/
 
 # modules
+/auth/
 /firestore/
 /storage/

package.json

@@ -10,6 +10,10 @@
             "require": "./lib/cjs/index.js",
             "default": "./lib/esm/index.js"
         },
+        "./auth": {
+            "require": "./lib/cjs/auth/index.js",
+            "default": "./lib/esm/auth/index.js"
+        },
         "./firestore": {
             "require": "./lib/cjs/firestore/index.js",
             "default": "./lib/esm/firestore/index.js"
@@ -21,6 +25,7 @@
     },
     "files": [
         "lib",
+        "auth",
         "firestore",
         "storage"
     ],

scripts/create-modules.js

@@ -1,6 +1,6 @@
 const fs = require("fs");
 
-const modules = ["firestore", "storage"];
+const modules = ["auth", "firestore", "storage"];
 for (const module of modules) {
     const packageJson = {
         main: `../lib/cjs/${module}/index.js`,

src/auth/index.ts

@@ -0,0 +1 @@
+export * from "./useAuthState";

src/auth/useAuthState.ts

@@ -0,0 +1,20 @@
+import { Auth, AuthError, onAuthStateChanged, User } from "firebase/auth";
+import { useEffect, useMemo } from "react";
+import { ValueHookResult } from "../common";
+import { useLoadingValue } from "../util/useLoadingValue";
+
+export type UseAuthStateResult = ValueHookResult<User | null, AuthError>;
+
+export function useAuthState(auth: Auth): UseAuthStateResult {
+    const { error, loading, setError, setValue, value } = useLoadingValue<User | null, AuthError>(auth.currentUser);
+
+    useEffect(() => {
+        const unsubscribe = onAuthStateChanged(auth, setValue, (e) => setError(e as AuthError));
+
+        return () => {
+            unsubscribe();
+        };
+    }, [auth]);
+
+    return useMemo(() => [value, loading, error], [value, loading, error]);
+}

src/index.ts

@@ -1,3 +1,4 @@
+export * from "./auth";
 export * from "./common";
 export * from "./firestore";
 export * from "./storage";