token-exchange.ts

import {throwFailedRequest} from '../../clients/common';
import {decodeSessionToken} from '../../session/decode-session-token';
import {sanitizeShop} from '../../utils/shop-validator';
import {ConfigInterface} from '../../base-types';
import {Session} from '../../session/session';
import {DataType} from '../../clients/types';
import {fetchRequestFactory} from '../../utils/fetch-request';

import {createSession} from './create-session';
import {AccessTokenResponse} from './types';

export enum RequestedTokenType {
  OnlineAccessToken = 'urn:shopify:params:oauth:token-type:online-access-token',
  OfflineAccessToken = 'urn:shopify:params:oauth:token-type:offline-access-token',
}

const TokenExchangeGrantType =
  'urn:ietf:params:oauth:grant-type:token-exchange';
const IdTokenType = 'urn:ietf:params:oauth:token-type:id_token';

export interface TokenExchangeParams {
  shop: string;
  sessionToken: string;
  requestedTokenType: RequestedTokenType;
}

export type TokenExchange = (
  params: TokenExchangeParams,
) => Promise<{session: Session}>;

export function tokenExchange(config: ConfigInterface): TokenExchange {
  return async ({
    shop,
    sessionToken,
    requestedTokenType,
  }: TokenExchangeParams) => {
    await decodeSessionToken(config)(sessionToken);

    const body = {
      client_id: config.apiKey,
      client_secret: config.apiSecretKey,
      grant_type: TokenExchangeGrantType,
      subject_token: sessionToken,
      subject_token_type: IdTokenType,
      requested_token_type: requestedTokenType,
    };

    const cleanShop = sanitizeShop(config)(shop, true)!;

    const postResponse = await fetchRequestFactory(config)(
      `https://${cleanShop}/admin/oauth/access_token`,
      {
        method: 'POST',
        body: JSON.stringify(body),
        headers: {
          'Content-Type': DataType.JSON,
          Accept: DataType.JSON,
        },
      },
    );

    if (!postResponse.ok) {
      throwFailedRequest(await postResponse.json(), false, postResponse);
    }

    return {
      session: createSession({
        accessTokenResponse: await postResponse.json<AccessTokenResponse>(),
        shop: cleanShop,
        // We need to keep this as an empty string as our template DB schemas have this required
        state: '',
        config,
      }),
    };
  };
}