This Pull request implement the authentication feature in the project; using the github oauth, our primary goal is to get and hold users github accessToken in cookies for performing specific functionality. It is important to state that this feature does not take store this user's accessToken to any remote server, this token and any other information that was retrieved using the token are all saved securely on the users' end through usage of cookies.

• Implemented the github oauth callback handler at /api/github/oauth/callback - this handler's main functionality is to receive github's authorization code and state to perform either of the following operations

  • Redirect to the path stated in the state params with the authorization code concatenated to it using the Astro.context.redirect method
  • or If a redirect=true value if found in the state param, then we redirect to the the path stated in the state params with the authorization code and redirect=true value concatenated to it using Astro.context.redirect method

• Implemented the github oauth authorization handler at /api/github/oauth/authorization - this handler is a helper that primarily exchanges the authorization code for tokens and returns it in a json object.

• Created a singleton instance of our github app at lib/octokit/app

• Added a new crypto util function which provides encrypt and decrypt helper function has exports; it is intended to be used for securing the users related cookies

• Implemented the doAuth action function - this function take the Astro global object as argument and performs the operations stated below

  /**
   * Authentication action with GitHub OAuth
   * @param {import("astro").AstroGlobal} astroGlobal 
   */
  export default async function doAuth(astroGlobal) {
    const { url: { searchParams }, cookies } = astroGlobal;
    const code = searchParams.get("code");
    const accessToken = cookies.get("jargons.dev:token", {
      decode: value => decrypt(value)
    });
  
    /**
     * Generate OAuth Url to start authorization flow
     * @todo make the `parsedState` data more predictable (order by path, redirect)
     * @todo improvement: store `state` in cookie for later retrieval in `github/oauth/callback` handler for cleaner url
     * @param {{ path?: string, redirect?: boolean }} state 
     */
    function getAuthUrl(state) {
      const parsedState = String(Object.keys(state).map(key => key + ":" + state[key]).join("|"));
      const { url } = app.oauth.getWebFlowAuthorizationUrl({
        state: parsedState
      });
      return url;
    }
  
    try {
      if (!accessToken && code) {
        const response = await GET(astroGlobal);
        const responseData = await response.json();
    
        if (responseData.accessToken && responseData.refreshToken) {
          cookies.set("jargons.dev:token", responseData.accessToken, {
            expires: resolveCookieExpiryDate(responseData.expiresIn),
            encode: value => encrypt(value)
          });
          cookies.set("jargons.dev:refresh-token", responseData.refreshToken, {
            expires: resolveCookieExpiryDate(responseData.refreshTokenExpiresIn),
            encode: value => encrypt(value)
          });
        }
      }
    
      const userOctokit = await app.oauth.getUserOctokit({ token: accessToken.value });
      const { data } = await userOctokit.request("GET /user");
    
      return {
        getAuthUrl,
        isAuthed: true,
        authedData: data
      }
    } catch (error) {
      return {
        getAuthUrl,
        isAuthed: false,
        authedData: null
      }
    }
  }
  • it provides (in its returned object) a helper function that can be used to generate a new github oauth url, this helper consumes our github app instance and it accepts a state object with path and redirectproperty to build out thestate` value that is held within the oauth url
  • it sets cookies data for tokens - it does this when it detects the presence of the authorization code in the Astro.url.searchParams and reads the absense no project related accessToken in cookie; this assumes that there's a new oauth flow going through it; It performs this operation by first calling the github oauth authorization handler at /api/github/oauth/authorization where it gets the tokens data that it adds to cookie and ensure its securely store by running the encrypt helper to encode it value
  • In cases where there's no authorization code in the Astro.url.searchParams and finds a project related token in cookie, It fetches users's data and provides it in its returned object for consumptions; it does this by getting the users octokit instance from our github app instance using the getUserOctokit method and the user's neccesasry tokens present in cookie; this users octokit instance is then used to request for user's data which is in turn returned
  • It also returns a boolean isAuthed property that can be used to determine whether a user is authenticated; this property is a statically computed property that only always returns turn when all operation reaches final execution point in the try block of the doAuth action function and it returns false when an error occurs anywhere in the operation to trigger the catch block of the doAuth action function

• Added the login page which stands as place where where unauthorised users witll be redirected to; this page integrates the doAuth action, destruing out the getAuthUrl helper and the isAuthed property, it uses them as follows

  const { getAuthUrl, isAuthed } = await doAuth(Astro);
  
  if (isAuthed) return redirect(searchParams.get("redirect"));
  
  const authUrl = getAuthUrl({
    path: searchParams.get("redirect"),
    redirect: true
  });
  • isAuthed - this property is check on the server-side on the page to check if a user is already authenticated from within the doAuth and redirects to the value stated the page's Astro.url.searchParams.get("redirect")
  • When a user is not authenticated, it uses the getAuthUrl to generate a new github oauth url and imperatively set the argument state.redirect to true
  • Implemented a new user store with a Map store value $userData to store user data to state

// pages/sandbox.astro

---
import BaseLayout from "../layouts/base.astro";
import doAuth from "../lib/actions/do-auth.js";
import { $userData } from "../stores/user.js";

const { url: { pathname }, redirect } = Astro;
const { isAuthed, authedData } = await doAuth(Astro);

if (!isAuthed) return redirect(`/login?redirect=${pathname}`);

$userData.set(authedData);
---

<BaseLayout pageTitle="Dictionary">
  <main class="flex flex-col max-w-screen-lg p-5 justify-center mx-auto min-h-screen">
    <div class="w-fit p-4 ring-2 rounded-full ring-gray-500 m-auto flex items-center space-x-3">
      <img class="w-10 h-10 p-1 rounded-full ring-2 ring-gray-500" 
        src={authedData.avatar_url} 
        alt={authedData.login}
      >
      <p>Hello, { authedData.login }</p>      
    </div>
  </main>
</BaseLayout>

Explainer

• We destructure isAuthed and authedData from the doAuth action
• Check whether a user is not authenticated? and do a redirect to login page stating the current pathname as value for the redirect search param (a data used in state to dictate where to redirect to after authentication complete) if no user is authenticated
• or Proceed to consuming the authedData which will be available when a isAuthed is true. by setting it to the $userData map store property

screencast-bpconcjcammlapcogcnnelfmaeghhagj-2024.03.29-20_36_15.webm

• Added new node package https://www.npmjs.com/package/@astrojs/node for SSR adapter intergation

This PR implements some improvement to mark the second iteration of the auth feature in the project. Follow-up to #8

• Addressed "todo make the parsedState data more predictable (order by path, redirect)" by implementing more predicatable manner of generating the state string for the oauth url; this is done by individually looking for the required state object key to fill in the parsedState string in required order. Leaving the new getAuthUrl helper function looking like so...

function getAuthUrl(state) {
  let parsedState = "";

  if (!isObjectEmpty(state)){
    if (state.path) parsedState += `path:${state.path}`;
    const otherStates = String(Object.keys(state)
      .filter(key => key !== "path" && key !== "redirect")
      .map(key => key + ":" + state[key]).join("|"));
    if (otherStates.length > 0) parsedState += `|${otherStates}`;
  }

  const { url } = app.oauth.getWebFlowAuthorizationUrl({
    state: parsedState
  });

  return url;
}

• Implemented a new utility function isObjectEmpty to check if an object has value or not
• Removed usage of redirect property in state object; its redundant 😮‍💨
• Renamed login redirect path params property name to return_to from redirect for readability reasons
• Implemented encodeURIComponent in login redirect path params value to stop its part on the url from looking like weird 😃;
  • Takes the example url from looking like this... /login?return_to=/editor to looking like so... /login?return_to=%2Feditor

Resolves #15

This Pull request refactors the authentication system, replacing the usage of github-app-oauth with classic github oauth app. This decision was taken because of the limitations discovered using the Pull Request endpoint (implementation in #25); the github-app-oauth uses permissions which requires a user to have write access to the upstream (i.e. write access to atleast pull-requests on our/this project repo) before a pull request can created from their forked repo branch to the main project repo.

This PR goes to implement classis oauth app, which uses scopes and allows user access to create the pull request to upstream repo on the public_repo scope. The changes made in this PR was done to mimic the normal Octokit.App's methods/apis as close as possible to allow compatibility with the implementation in #8 and #28 (or for cases when we revert back to using the github-app-oauth in the future --- maybe we end up finding a solution because honestly I really prefer the github-app-oauth 😉).

It is also important to state that this oauth app option doesn't offer a short lived token (hence we only have an accessToken without expiry and No refreshToken), but I have configured the token to expire out of cookie in 8hours; even though we might be getting exactly thesame token back from github after this expires and we re-authorize the flow, I just kinda like that feeling of the cookies expiring after some hours and asking user to re-auth.

• Initialized a new app object that returns few methods and objects

  • octokit - the main octokit instance of the oauth app

    /**
     * OAuth App's Octokit instance
     */
    const octokit = new Octokit({
      authStrategy: createOAuthAppAuth,
      auth: {
        clientId: import.meta.env.GITHUB_OAUTH_APP_CLIENT_ID,
        clientSecret: import.meta.env.GITHUB_OAUTH_APP_CLIENT_SECRET
      },
    });

  • oauth

    • getWebFlowAuthorizationUrl - method that generates the oauth flow url

      /**
       * Generate a Web Flow/OAuth authorization url to start an OAuth flow
       * @param {import("@octokit/oauth-authorization-url").OAuthAppOptions} options
       * @returns 
       */
      function getWebFlowAuthorizationUrl({state, scopes = ["public_repo"], ...options }) {
        return oauthAuthorizationUrl({
          clientId: import.meta.env.GITHUB_OAUTH_APP_CLIENT_ID,
          state,
          scopes,
          ...options
        });
      }

    • exchangeWebFlowCode - method that exchanges oauth web flow returned code for accessToken; this functionality was extracted from the github/oauth/authorize endpoint to have all auth related function packed in one place

      /**
       * Exchange Web Flow Authorization `code` for an `access_token` 
       * @param {string} code 
       * @returns {Promise<{access_token: string, scope: string, token_type: string}>}
       */
      async function exchangeWebFlowCode(code) {
        const queryParams = new URLSearchParams();
        queryParams.append("code", code);
        queryParams.append("client_id", import.meta.env.GITHUB_OAUTH_APP_CLIENT_ID);
        queryParams.append("client_secret", import.meta.env.GITHUB_OAUTH_APP_CLIENT_SECRET);
      
        const response = await fetch("https://github.com/login/oauth/access_token", {
            method: "POST",
            body: queryParams
          });
        const responseText = await response.text();
        const responseData = new URLSearchParams(responseText);
      
        return responseData;
      }

  • getUserOctokit - method that gets an octokit instance of a user.

    /**
     * Get a User's Octokit instance
     * @param {Omit<OctokitOptions, "auth"> & { token: string }} options
     * @returns {Octokit}
     */
    function getUserOctokit({ token, ...options }) {
      return new Octokit({
        auth: token,
        ...options
      });
    };
• Integrated the app.oauth.exchangeWebFlowCode method into the github/oauth/authorize endpoint handler
• Removed the refreshToken and refreshTokenExpiresIn from github/oauth/authorize endpoint response object.
• Modified doAuth actions
  • Removed jargons.dev:refresh_token value set to cookie;
  • Corrected computation of userOctokit to use app.getUserOctokit from app.oauth.getUserOctokit (even though I could just move the getUserOctokit method to the app.oauth object in the new implmentation, I just prefer it this way 😉).

📖

screencast-bpconcjcammlapcogcnnelfmaeghhagj-2024.04.07-07_37_31.webm