Authsession

auth-session.tsx

async function authorize(
): Promise<Token> {
        const authReqConfig: AuthSession.AuthRequestConfig = {
            clientId: CONST.AUT.CLIENT_ID,
            codeChallengeMethod: CodeChallengeMethod.S256,
            extraParams: {
                realm: CONST.AUT.REALM,
                acr_values: CONST.AUT.ACR,
                prompt: "Login",
            },
            redirectUri: CONST.AUT.REDIRECT_URI,
            scopes: ["openid", "scopes"],
            usePKCE: true,
        };

        const discoveryConfig: AuthSession.DiscoveryDocument = {
            authorizationEndpoint: CONST.AUT.AUTENDPOINT,
            tokenEndpoint: CONST.AUT.TOKENENDPOINT,
        };

        const request = new AuthSession.AuthRequest(authReqConfig);
        return request
            .promptAsync(discoveryConfig,  {
                // @ts-expect-error
                preferEphemeralSession: true,
                createTask: false,
              })
            .then(async (response) => {
                switch (response.type) {
                    case "success": {
                        const { code } = response.params;
                        const accessTokenReq: AuthSession.AccessTokenRequest =
                            new AuthSession.AccessTokenRequest({
                                clientId: CONST.AUT.CLIENT_ID,
                                code: code,
                                redirectUri: CONST.AUT.REDIRECT_URI,
                                extraParams: {
                                    code_verifier: request?.codeVerifier
                                        ? request.codeVerifier
                                        : "",
                                },
                            });

                        const responseToken: AuthSession.TokenResponse =
                            await AuthSession.exchangeCodeAsync(accessTokenReq, {
                                tokenEndpoint: discoveryConfig.tokenEndpoint,
                            });
                        return responseToken;
                    }
                    case "dismiss": {
                        throw new Error("User dismissed the login prompt")
                    }
                    case "error": {
                        throw new Error("Error during login");
                    }
                }
            })
            .catch((error) => {
                throw new Error("Error during login", error);
            });
}