From e0a009c13fc204e01bb82dbecb1730d3ba98f4bb Mon Sep 17 00:00:00 2001
From: Joseph Garrone <joseph.garrone.gj@gmail.com>
Date: Tue, 24 Oct 2023 12:23:16 +0200
Subject: [PATCH] #3

---
 README.md   | 33 +++++++++++++++++++++++----------
 src/oidc.ts | 42 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 59 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index ec5b770..3265566 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,7 @@ import { createOidc, decodeJwt } from "oidc-spa";
         issuerUri: "https://auth.your-domain.net/auth/realms/myrealm",
         clientId: "myclient",
         // Optional, you can modify the url before redirection to the identity server
+        // Alternatively you can use: getExtraQueryParams: ()=> ({ ui_locales: "fr" })
         transformUrlBeforeRedirect: url => `${url}&ui_locales=fr`
         /**
          * This parameter have to be provided provide if your App is not hosted at the origin of the subdomain.
@@ -85,14 +86,18 @@ import { createOidc, decodeJwt } from "oidc-spa";
     });
 
     if (oidc.isUserLoggedIn) {
-        // This return a promise that never resolve. Your user will be redirected to the identity server.
-        // doesCurrentHrefRequiresAuth determines the behavior when a user gives up on loggin in and navigate back.
-        // We don't want to send him back to a authenticated route.
-        // If you are calling login because the user clicked
-        // on a 'login' button you should set doesCurrentHrefRequiresAuth to false.
-        // When you are calling login because your user navigated to a path that require authentication
-        // you should set doesCurrentHrefRequiresAuth to true
-        oidc.login({ doesCurrentHrefRequiresAuth: false });
+        oidc.login({
+            // This return a promise that never resolve. Your user will be redirected to the identity server.
+            // doesCurrentHrefRequiresAuth determines the behavior when a user gives up on loggin in and navigate back.
+            // We don't want to send him back to a authenticated route.
+            // If you are calling login because the user clicked
+            // on a 'login' button you should set doesCurrentHrefRequiresAuth to false.
+            // When you are calling login because your user navigated to a path that require authentication
+            // you should set doesCurrentHrefRequiresAuth to true
+            doesCurrentHrefRequiresAuth: false
+            //Optionally you can add some extra parameter to be added on the login url.
+            //extraQueryParams: { kc_idp_hint: "google" }
+        });
     } else {
         const {
             // The accessToken is what you'll use as a Bearer token to authenticate to your APIs
@@ -145,8 +150,16 @@ function App() {
         return (
             <>
                 You're not logged in.
-                <button onClick={() => oidc.login({ doesCurrentHrefRequiresAuth: false })}>
-                    Login now
+                <button
+                    onClick={() =>
+                        oidc.login({
+                            doesCurrentHrefRequiresAuth: false
+                            //Optionally you can add some extra parameter to be added on the login url.
+                            //extraQueryParams: { kc_idp_hint: "google" }
+                        })
+                    }
+                >
+                    Login
                 </button>
             </>
         );
diff --git a/src/oidc.ts b/src/oidc.ts
index 4b106f0..5d27745 100644
--- a/src/oidc.ts
+++ b/src/oidc.ts
@@ -18,7 +18,10 @@ export declare namespace Oidc {
 
     export type NotLoggedIn = Common & {
         isUserLoggedIn: false;
-        login: (params: { doesCurrentHrefRequiresAuth: boolean }) => Promise<never>;
+        login: (params: {
+            doesCurrentHrefRequiresAuth: boolean;
+            extraQueryParams?: Record<string, string>;
+        }) => Promise<never>;
     };
 
     export type LoggedIn = Common & {
@@ -45,6 +48,7 @@ export async function createOidc(params: {
     issuerUri: string;
     clientId: string;
     transformUrlBeforeRedirect?: (url: string) => string;
+    getExtraQueryParams?: () => Record<string, string>;
     /**
      * This parameter have to be provided provide if your App is not hosted at the origin of the subdomain.
      * For example if your site is hosted by navigating to `https://www.example.com`
@@ -60,7 +64,13 @@ export async function createOidc(params: {
      */
     publicUrl?: string;
 }): Promise<Oidc> {
-    const { issuerUri, clientId, transformUrlBeforeRedirect = url => url, publicUrl = "" } = params;
+    const {
+        issuerUri,
+        clientId,
+        transformUrlBeforeRedirect = url => url,
+        getExtraQueryParams,
+        publicUrl = ""
+    } = params;
 
     const configHash = fnv1aHashToHex(`${issuerUri} ${clientId}`);
     const configHashKey = "configHash";
@@ -75,10 +85,14 @@ export async function createOidc(params: {
         "silent_redirect_uri": `${window.location.origin}${publicUrl}/silent-sso.html?${configHashKey}=${configHash}`
     });
 
-    const login: Oidc.NotLoggedIn["login"] = async ({ doesCurrentHrefRequiresAuth }) => {
+    const login: Oidc.NotLoggedIn["login"] = async ({
+        doesCurrentHrefRequiresAuth,
+        extraQueryParams
+    }) => {
         //NOTE: We know there is a extraQueryParameter option but it doesn't allow
-        // to control the encoding so we have to hack the global URL Class that is
-        // used internally by oidc-client-ts
+        // to control the encoding so we have to highjack global URL Class that is
+        // used internally by oidc-client-ts. It's save to do so since this is the
+        // last thing that will be done before the redirect.
 
         const URL_real = window.URL;
 
@@ -88,7 +102,23 @@ export async function createOidc(params: {
             return new Proxy(urlInstance, {
                 "get": (target, prop) => {
                     if (prop === "href") {
-                        return transformUrlBeforeRedirect(urlInstance.href);
+                        let url = urlInstance.href;
+
+                        Object.entries({
+                            ...getExtraQueryParams?.(),
+                            ...extraQueryParams
+                        }).forEach(
+                            ([name, value]) =>
+                                (url = addQueryParamToUrl({
+                                    url,
+                                    name,
+                                    value
+                                }).newUrl)
+                        );
+
+                        url = transformUrlBeforeRedirect(url);
+
+                        return url;
                     }
 
                     //@ts-expect-error