feat: require clientSecret in getAccessToken (#2)

BREAKING CHANGE: now requires to set client secret as there is no support for PKCE with only client ID.

Author: Copilot

README.md

@@ -20,5 +20,5 @@ pnpm add @soliantconsulting/bitbucket-cloud-cli-auth
 ```typescript
 import { getAccessToken } from "@soliantconsulting/bitbucket-cloud-cli-auth";
 
-const accessToken = await getAccessToken(clientId, port);
+const accessToken = await getAccessToken(clientId, clientSecret, port);
 ```

src/index.ts

@@ -10,7 +10,7 @@ const generateCodeVerifier = (): string => randomBytes(32).toString("base64url")
 const generateCodeChallenge = (codeVerifier: string): string =>
     createHash("sha256").update(codeVerifier).digest("base64url");
 
-export const getAccessToken = async (clientId: string, port: number): Promise<string> => {
+export const getAccessToken = async (clientId: string, clientSecret: string, port: number): Promise<string> => {
     const codeVerifier = generateCodeVerifier();
     const codeChallenge = generateCodeChallenge(codeVerifier);
     const redirectUri = `http://localhost:${port}/`;
@@ -38,6 +38,7 @@ export const getAccessToken = async (clientId: string, port: number): Promise<st
                             grant_type: "authorization_code",
                             code,
                             client_id: clientId,
+                            client_secret: clientSecret,
                             code_verifier: codeVerifier,
                             redirect_uri: redirectUri,
                         }),