Adds getGroupTreeIds(..) method to the Groups service + fixes

Author: birdofpreyru

CHANGELOG.md

@@ -1,10 +1,11 @@
 # Topcoder React Lib
 
-### v0.7.3
+### v0.7.4
 - Added `getTcM2mToken()` function to API service, to facilitate handling of
   TC M2M token;
-- Added `reduceGroupIds(..)` function to Groups service, to easily extract all
-  IDs from a group tree.
+- Added `getGroupTreeIds(..)`, `getTokenV3()`, and `reduceGroupIds(..)`
+  functions to the Groups service, to facilitate deduction of all IDs in a group
+  (sub-)tree, rooted at a specified group.
 
 ### v0.6.0
 A few changes related to fetch of projests visitble to users, and creation of

src/services/api.js

@@ -302,15 +302,17 @@ export async function getTcM2mToken() {
   const { cached } = getTcM2mToken;
   const { TC_M2M } = config.SECRET;
   if (!cached || cached.expires < now + getTcM2mToken.MIN_LIFETIME) {
-    const res = await fetch(`https://${config.AUTH0.DOMAIN}/oauth/token`, {
-      body: {
+    let res = await fetch(`https://${config.AUTH0.DOMAIN}/oauth/token`, {
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
         client_id: TC_M2M.CLIENT_ID,
         client_secret: TC_M2M.CLIENT_SECRET,
         audience: TC_M2M.AUDIENCE,
         grant_type: TC_M2M.GRANT_TYPE,
-      },
+      }),
       method: 'POST',
     });
+    res = await res.json();
     getTcM2mToken.cached = {
       expires: now + 1000 * res.expires_in, // [ms]
       token: res.access_token,

src/services/groups.js

@@ -191,8 +191,15 @@ class GroupService {
    * @param {String} tokenV3 Optional. Auth token for Topcoder API v3.
    */
   constructor(tokenV3) {
+    const now = Date.now();
     this.private = {
       api: getApiV3(tokenV3),
+      cache: {
+        groupTreeIds: {
+          lastCleanUp: now,
+          data: {},
+        },
+      },
       tokenV3,
     };
   }
@@ -269,6 +276,48 @@ class GroupService {
     return Promise.all(promises).then(() => res);
   }
 
+  /**
+   * Given a root group ID, returns an ID array that contains the root group ID,
+   * and IDs of all descendant groups in the group (sub-)tree rooted at the
+   * specified group.
+   *
+   * Results are cached inside the class instance to minimize the load on TC
+   * Group API. To take advantage of that, be sure to keep and reuse the same
+   * class instance.
+   *
+   * The reason to have such strange method and pay an extra attention to its
+   * optimization for smaller API load is that it is essential for authorization
+   * checks.
+   *
+   * @param {String} rootGroupId
+   * @param {Number} maxage Optional. Max age [ms] of records served from the
+   *  cache. Defaults to 5 minutes.
+   * @return {Promise} Resolves to ID array.
+   */
+  async getGroupTreeIds(rootGroupId, maxage = 5 * 60 * 1000) {
+    const now = Date.now();
+    const cache = this.private.cache.groupTreeIds;
+
+    /* Clean-up: removes stale records from the cache. */
+    const CLEAN_UP_INTERVAL = 24 * 60 * 60 * 1000; // 1 day in ms.
+    if (now - cache.lastCleanUp > CLEAN_UP_INTERVAL) {
+      _.forOwn(cache, ({ timestamp }, key) => {
+        if (now - timestamp > CLEAN_UP_INTERVAL) delete cache[key];
+      });
+      cache.lastCleanUp = now;
+    }
+
+    /* If result is found in cache, and is fresh enough, return it. */
+    const cached = cache[rootGroupId];
+    if (cached && now - cached.timestamp < maxage) return _.clone(cached.data);
+
+    /* Otherwise, fetch result from the API, write it to the cache, and
+     * finally return that. */
+    const res = reduceGroupIds(await this.getGroup(rootGroupId));
+    cache[rootGroupId] = { data: res, timestamp: now };
+    return _.clone(res);
+  }
+
   /**
    * Gets group members.
    * @param {String} groupId
@@ -296,6 +345,14 @@ class GroupService {
     if (!res.success) throw new Error(res.content);
     return Number(res.content);
   }
+
+  /**
+   * Returns TC Auth Token V3 used by the service instance.
+   * @return {String} Token.
+   */
+  getTokenV3() {
+    return this.private.tokenV3;
+  }
 }
 
 let lastInstance = null;