[openid-client] Add more detailed types to introspection response as per RFC7662 (#37319)

* [openid-client] add more detailed types to introspection respose

* [openid-client] scope type as string

* Make additional responses unknown, and make types readonly

types/openid-client/index.d.ts

@@ -2,6 +2,7 @@
 // Project: https://github.com/panva/node-openid-client
 // Definitions by: ulrichb <https://github.com/ulrichb>
 //                 Brandon Shelton <https://github.com/YangusKhan>
+//                 Richard Honor <https://github.com/RMHonor>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 3.0
 
@@ -89,6 +90,22 @@ export interface EndSessionUrlParameters {
     readonly state?: string;
 }
 
+export interface IntrospectionResponse {
+    readonly active: boolean;
+    readonly scope?: string;
+    readonly client_id?: string;
+    readonly username?: string;
+    readonly token_type?: string;
+    readonly exp?: number;
+    readonly iat?: number;
+    readonly nbf?: number;
+    readonly sub?: string;
+    readonly aud?: string;
+    readonly iss?: string;
+    readonly jti?: string;
+    readonly [key: string]: unknown;
+}
+
 export class Client {
     static [custom.http_options]: CustomHttpOptionsProvider;
 
@@ -127,7 +144,7 @@ export class Client {
         token: string,
         tokenTypeHint?: string,
         extras?: { readonly introspectBody?: object }
-    ): Promise<{ readonly [name: string]: {} | null | undefined }>;
+    ): Promise<IntrospectionResponse>;
 }
 
 export class TokenSet {

types/openid-client/openid-client-tests.ts

@@ -1,5 +1,9 @@
 import { IncomingMessage } from 'http';
-import { Issuer, generators, custom } from 'openid-client';
+import {
+  custom,
+  generators,
+  Issuer,
+} from 'openid-client';
 
 async (req: IncomingMessage) => {
     // Custom HTTP options on the `Issuer` _c'tor_ (e.g. used for `Issuer.discover()`):
@@ -90,6 +94,7 @@ async (req: IncomingMessage) => {
     //
 
     const introspectResponse = await client.introspect('token');
+    const active: boolean = introspectResponse.active;
     console.log(introspectResponse['some claim name']);
 
     client.introspect('token', 'tokenTypeHint');