Factor out firebase.tsx, FirebaseAppContext (#216)

This factors out a ` firebase.tsx` file and a `FirebaseAppContext` in preparation for gallery work (#26).

lib/auth-context.tsx

@@ -0,0 +1,38 @@
+import React from "react";
+
+/**
+ * Generic interface for authentication.
+ */
+export interface AuthContext {
+  /**
+   * The currently logged-in user. This will be
+   * null if the user isn't logged in, otherwise it will
+   * be their name.
+   */
+  loggedInUser: string | null;
+
+  /**
+   * The name of the authentication provider, e.g. "GitHub",
+   * or null if auth is disabled.
+   */
+  providerName: string | null;
+
+  /**
+   * If authentication failed for some reason, this will
+   * be a string describing the error.
+   */
+  error?: string;
+
+  /** Begin the login UI flow. */
+  login(): void;
+
+  /** Log out the user. */
+  logout(): void;
+}
+
+export const AuthContext = React.createContext<AuthContext>({
+  loggedInUser: null,
+  providerName: null,
+  login() {},
+  logout() {},
+});

lib/auth.tsx

@@ -1,105 +0,0 @@
-import { FirebaseApp, FirebaseOptions, initializeApp } from "firebase/app";
-import {
-  getAuth,
-  signInWithPopup,
-  GithubAuthProvider,
-  onAuthStateChanged,
-  signOut,
-  Auth,
-  User,
-} from "firebase/auth";
-import React, { useCallback, useEffect, useState } from "react";
-
-const DEFAULT_APP_CONFIG: FirebaseOptions = {
-  apiKey: "AIzaSyAV1kkVvSKEicEa8rLke9o_BxYBu1rb8kw",
-  authDomain: "mystic-addaf.firebaseapp.com",
-  projectId: "mystic-addaf",
-  storageBucket: "mystic-addaf.appspot.com",
-  messagingSenderId: "26787182745",
-  appId: "1:26787182745:web:e4fbd9439b9279fe966008",
-  measurementId: "G-JHKRSK1PR6",
-};
-
-/**
- * Generic interface for authentication.
- */
-export interface AuthContext {
-  /**
-   * The currently logged-in user. This will be
-   * null if the user isn't logged in, otherwise it will
-   * be their name.
-   */
-  loggedInUser: string | null;
-
-  /**
-   * The name of the authentication provider, e.g. "GitHub",
-   * or null if auth is disabled.
-   */
-  providerName: string | null;
-
-  /**
-   * If authentication failed for some reason, this will
-   * be a string describing the error.
-   */
-  error?: string;
-
-  /** Begin the login UI flow. */
-  login(): void;
-
-  /** Log out the user. */
-  logout(): void;
-}
-
-type FirebaseGithubAuthState = {
-  app: FirebaseApp;
-  auth: Auth;
-  provider: GithubAuthProvider;
-};
-
-/**
- * A Firebase GitHub authentication provider.
- *
- * Note this component is assumed to never be unmounted, nor
- * for its props to change.
- */
-export const FirebaseGithubAuthProvider: React.FC<{
-  config?: FirebaseOptions;
-}> = ({ config, children }) => {
-  const [state, setState] = useState<FirebaseGithubAuthState | null>(null);
-  const [user, setUser] = useState<User | null>(null);
-  const [error, setError] = useState<string | undefined>(undefined);
-
-  const handleError = (e: Error) => setError(e.message);
-
-  useEffect(() => {
-    const app = initializeApp(config || DEFAULT_APP_CONFIG);
-    const auth = getAuth(app);
-    const provider = new GithubAuthProvider();
-
-    setState({ app, auth, provider });
-    onAuthStateChanged(auth, setUser);
-  }, [config]);
-
-  const context: AuthContext = {
-    loggedInUser: user && user.displayName,
-    providerName: "GitHub",
-    error,
-    login: useCallback(() => {
-      setError(undefined);
-      state && signInWithPopup(state.auth, state.provider).catch(handleError);
-    }, [state]),
-    logout: useCallback(() => {
-      setError(undefined);
-      state && signOut(state.auth).catch(handleError);
-    }, [state]),
-  };
-
-  return <AuthContext.Provider value={context} children={children} />;
-};
-
-export const AuthContext = React.createContext<AuthContext>({
-  loggedInUser: null,
-  providerName: null,
-  login() {},
-  logout() {},
-});

lib/browser-main.tsx

@@ -1,6 +1,6 @@
 import React, { useCallback, useEffect, useState } from "react";
 import ReactDOM from "react-dom";
-import { FirebaseGithubAuthProvider } from "./auth";
+import { FirebaseAppProvider, FirebaseGithubAuthProvider } from "./firebase";
 import { PageContext, PAGE_QUERY_ARG } from "./page";
 import { pageNames, Pages, toPageName, DEFAULT_PAGE } from "./pages";
 
@@ -57,11 +57,13 @@ const App: React.FC<{}> = (props) => {
   };
 
   return (
-    <FirebaseGithubAuthProvider>
-      <PageContext.Provider value={ctx}>
-        <PageComponent />
-      </PageContext.Provider>
-    </FirebaseGithubAuthProvider>
+    <FirebaseAppProvider>
+      <FirebaseGithubAuthProvider>
+        <PageContext.Provider value={ctx}>
+          <PageComponent />
+        </PageContext.Provider>
+      </FirebaseGithubAuthProvider>
+    </FirebaseAppProvider>
   );
 };
 

lib/firebase.tsx

@@ -0,0 +1,92 @@
+import { FirebaseApp, FirebaseOptions, initializeApp } from "firebase/app";
+import {
+  getAuth,
+  signInWithPopup,
+  GithubAuthProvider,
+  onAuthStateChanged,
+  signOut,
+  Auth,
+  User,
+} from "firebase/auth";
+import React, { useCallback, useContext, useEffect, useState } from "react";
+import { AuthContext } from "./auth-context";
+
+const DEFAULT_APP_CONFIG: FirebaseOptions = {
+  apiKey: "AIzaSyAV1kkVvSKEicEa8rLke9o_BxYBu1rb8kw",
+  authDomain: "mystic-addaf.firebaseapp.com",
+  projectId: "mystic-addaf",
+  storageBucket: "mystic-addaf.appspot.com",
+  messagingSenderId: "26787182745",
+  appId: "1:26787182745:web:e4fbd9439b9279fe966008",
+  measurementId: "G-JHKRSK1PR6",
+};
+
+type FirebaseAppContext = {
+  app: FirebaseApp;
+  auth: Auth;
+  provider: GithubAuthProvider;
+};
+
+export const FirebaseAppContext =
+  React.createContext<FirebaseAppContext | null>(null);
+
+/**
+ * A Firebase app provider.  Any other components that use Firebase must
+ * be a child of this.
+ *
+ * Note this component is assumed to never be unmounted, nor
+ * for its non-children props to change.
+ */
+export const FirebaseAppProvider: React.FC<{ config?: FirebaseOptions }> = ({
+  config,
+  children,
+}) => {
+  const [value, setValue] = useState<FirebaseAppContext | null>(null);
+
+  useEffect(() => {
+    const app = initializeApp(config || DEFAULT_APP_CONFIG);
+    const auth = getAuth(app);
+    const provider = new GithubAuthProvider();
+
+    setValue({ app, auth, provider });
+  }, [config]);
+
+  return <FirebaseAppContext.Provider value={value} children={children} />;
+};
+
+/**
+ * A Firebase GitHub authentication provider.  Must be a child of a
+ * `FirebaseAppProvider`.
+ *
+ * Note this component is assumed to never be unmounted.
+ */
+export const FirebaseGithubAuthProvider: React.FC<{}> = ({ children }) => {
+  const appCtx = useContext(FirebaseAppContext);
+  const [user, setUser] = useState<User | null>(null);
+  const [error, setError] = useState<string | undefined>(undefined);
+
+  const handleError = (e: Error) => setError(e.message);
+
+  useEffect(() => {
+    if (!appCtx) return;
+
+    onAuthStateChanged(appCtx.auth, setUser);
+  }, [appCtx]);
+
+  const context: AuthContext = {
+    loggedInUser: user && user.displayName,
+    providerName: appCtx && "GitHub",
+    error,
+    login: useCallback(() => {
+      setError(undefined);
+      appCtx &&
+        signInWithPopup(appCtx.auth, appCtx.provider).catch(handleError);
+    }, [appCtx]),
+    logout: useCallback(() => {
+      setError(undefined);
+      appCtx && signOut(appCtx.auth).catch(handleError);
+    }, [appCtx]),
+  };
+
+  return <AuthContext.Provider value={context} children={children} />;
+};

lib/pages/debug-page.tsx

@@ -1,5 +1,5 @@
 import React, { useContext, useState } from "react";
-import { AuthContext } from "../auth";
+import { AuthContext } from "../auth-context";
 import { AutoSizingSvg } from "../auto-sizing-svg";
 import { CreatureContext, CreatureContextType } from "../creature-symbol";
 import { createCreatureSymbolFactory } from "../creature-symbol-factory";