ci(docs-infra): change AIO preview server stuff to pull builds from CircleCI

Previously, Travis pushed the build artitfacts to the preview server.
This required us to use JWT to secure the POST request from Travis, to
ensure we couldn't receive malicious builds.

JWT has been deprecated and we are moving our builds to CircleCI.

This commit rewrites the TypeScript part of the preview server that
handles converting build artifact into hosted previews of the docs.

aio/aio-builds-setup/dockerbuild/scripts-js/lib/common/github-teams.ts

@@ -1,45 +1,72 @@
-// Imports
 import {assertNotMissingOrEmpty} from '../common/utils';
 import {GithubApi} from './github-api';
 
-// Interfaces - Types
-interface Team {
+export interface Team {
   id: number;
   slug: string;
 }
 
-interface TeamMembership {
+export interface TeamMembership {
   state: string;
 }
 
-// Classes
-export class GithubTeams extends GithubApi {
-  // Constructor
-  constructor(githubToken: string, protected organization: string) {
-    super(githubToken);
-    assertNotMissingOrEmpty('organization', organization);
+export class GithubTeams {
+  /**
+   * Create an instance of this helper
+   * @param api An instance of the Github API helper.
+   * @param githubOrg The organisation on GitHub whose repo we will interrogate.
+   */
+  constructor(private api: GithubApi, protected githubOrg: string) {
+    assertNotMissingOrEmpty('githubOrg', githubOrg);
   }
 
-  // Methods - Public
-  public fetchAll(): Promise<Team[]> {
-    return this.getPaginated<Team>(`/orgs/${this.organization}/teams`);
+  /**
+   * Request information about all the organisation's teams in GitHub.
+   * @returns A promise that is resolved with information about the teams.
+   */
+  public fetchAll() {
+    return this.api.getPaginated<Team>(`/orgs/${this.githubOrg}/teams`);
   }
 
-  public isMemberById(username: string, teamIds: number[]): Promise<boolean> {
-    const getMembership = (teamId: number) =>
-      this.get<TeamMembership>(`/teams/${teamId}/memberships/${username}`).
-        then(membership => membership.state === 'active').
-        catch(() => false);
-    const reduceFn = (promise: Promise<boolean>, teamId: number) =>
-      promise.then(isMember => isMember || getMembership(teamId));
+  /**
+   * Check whether the specified username is a member of the specified team.
+   * @param username The usernane to check for in the team.
+   * @param teamIds The team to check for the username.
+   * @returns a Promise that resolves to `true` if the username is a member of the team.
+   */
+  public async isMemberById(username: string, teamIds: number[]) {
 
-    return teamIds.reduce(reduceFn, Promise.resolve(false));
+    const getMembership = async (teamId: number) => {
+      try {
+        const {state} = await this.api.get<TeamMembership>(`/teams/${teamId}/memberships/${username}`);
+        return state === 'active';
+      } catch (error) {
+        return false;
+      }
+    };
+
+    for (const teamId of teamIds) {
+      if (await getMembership(teamId)) {
+        return true;
+      }
+    }
+
+    return false;
   }
 
-  public isMemberBySlug(username: string, teamSlugs: string[]): Promise<boolean> {
-    return this.fetchAll().
-      then(teams => teams.filter(team => teamSlugs.includes(team.slug)).map(team => team.id)).
-      then(teamIds => this.isMemberById(username, teamIds)).
-      catch(() => false);
+  /**
+   * Check whether the given username is a member of the teams specified by the team slugs.
+   * @param username The username to check for in the teams.
+   * @param teamSlugs A collection of slugs that represent the teams to check for the the username.
+   * @returns a Promise that resolves to `true` if the usernane is a member of at least one of the specified teams.
+   */
+  public async isMemberBySlug(username: string, teamSlugs: string[]) {
+    try {
+      const teams = await this.fetchAll();
+      const teamIds = teams.filter(team => teamSlugs.includes(team.slug)).map(team => team.id);
+      return await this.isMemberById(username, teamIds);
+    } catch (error) {
+      return false;
+    }
   }
 }