feat(apps): create githubWebhook function

Create initial function for handling githubWebhooks to store pull request information.

apps/functions/BUILD.bazel

@@ -17,6 +17,7 @@ ts_library(
         "index.ts",
     ],
     deps = [
+        "//apps/functions/githubWebhook",
         "@npm//firebase-functions",
     ],
 )
@@ -26,7 +27,7 @@ esbuild(
     entry_points = [
         "index.ts",
     ],
-    format = "cjs",
+    format = "esm",
     visibility = ["//apps:__pkg__"],
     deps = [
         ":functions",

apps/functions/githubWebhook/BUILD.bazel

@@ -0,0 +1,29 @@
+load("//tools:defaults.bzl", "ts_library")
+
+package(default_visibility = ["//visibility:private"])
+
+ts_library(
+    name = "githubWebhook",
+    srcs = [
+        "index.ts",
+    ],
+    visibility = [
+        "//apps/functions:__pkg__",
+    ],
+    deps = [
+        ":webhooks",
+        "@npm//firebase-admin",
+        "@npm//firebase-functions",
+    ],
+)
+
+ts_library(
+    name = "webhooks",
+    srcs = [
+        "pull-request.ts",
+    ],
+    deps = [
+        "//apps/shared/models:server",
+        "@npm//@octokit/webhooks-types",
+    ],
+)

apps/functions/githubWebhook/index.ts

@@ -0,0 +1,34 @@
+import * as functions from 'firebase-functions';
+import * as admin from 'firebase-admin';
+import {handlePullRequestEvent} from './pull-request';
+
+admin.initializeApp({...functions.firebaseConfig()});
+
+/**
+ * Firebase function to handle all incoming webhooks from Github. This function checks the incoming
+ * webhook to ensure it is a valid request from Github, and then delegates processing of a payload
+ * to one of the other githubWebhook functions.
+ */
+export const githubWebhook = functions
+  .runWith({invoker: 'public', timeoutSeconds: 30, minInstances: 1})
+  .https.onRequest(async (request, response) => {
+    if (request.method !== 'POST') {
+      response.status(405);
+      response.send('Requests must be made using the POST method.');
+      return;
+    }
+    if (request.headers['content-type'] !== 'application/json') {
+      response.status(415);
+      response.send('Request payloads must be "application/json".');
+      return;
+    }
+
+    if (request.get('X-GitHub-Event') === 'pull_request') {
+      await handlePullRequestEvent(request.body);
+      response.send(`Handled pull request update for pr #${request.body.pull_request.number}`);
+      response.end();
+      return;
+    }
+
+    response.end();
+  });

apps/functions/githubWebhook/pull-request.ts

@@ -0,0 +1,8 @@
+import {PullRequestEvent} from '@octokit/webhooks-types';
+import {PullRequest} from '../../shared/models/server-models';
+
+export async function handlePullRequestEvent(event: PullRequestEvent) {
+  const docRef = PullRequest.converter.getFirestoreRefForGithubModel(event.pull_request);
+  const pullRequest = PullRequest.converter.fromGithub(event.pull_request);
+  await docRef.set(pullRequest);
+}

apps/functions/index.ts

@@ -1 +1 @@
-import * as functions from 'firebase-functions';
+export {githubWebhook} from './githubWebhook/index';

apps/shared/models/app-models.ts

@@ -21,7 +21,6 @@ export const Status = forApp(GithubStatus);
 export const Team = forApp(GithubTeam);
 export const Check = forApp(GithubCheck);
 
-
 /**
  * Mixin for models, allowing them to be used in web app environments leveraging Firestore. This
  * mixin provides the `converter` object used for reading and writing to Firestore, using the

apps/shared/models/base.ts

@@ -1,4 +1,3 @@
-
 /**
  * Because it is less expensive to store strings than Firestore references, with no change in the
  * value it provides, we have this local type to express this usage.
@@ -21,4 +20,3 @@ export abstract class GithubBaseModel<T> extends BaseModel<T> {
   /** Helper functions for translating Github objects to Firestore. */
   protected static githubHelpers: GithubHelperFunctions<any, any> | undefined;
 }
-

apps/shared/models/pull-request.ts

@@ -6,7 +6,7 @@ import {GithubTeam} from './team';
 import {GithubUser, isUserFromGithub} from './user';
 
 interface FirestorePullRequest {
-  owner:  FirestoreReference<GithubUser>;
+  owner: FirestoreReference<GithubUser>;
   repo: string;
   node: string;
   state: PullRequest['state'];

apps/shared/models/server-models.ts

@@ -31,7 +31,7 @@ type WithAdminFirestoreDataConverter<Model> = Model & {
 /**
  * A model which has been setup for usage in a Firebase functions (firebase-admin) environment,
  * with additional expectation/support for converting from a Github webhook payload.
-*/
+ */
 type WithAdminFirestoreDataConverterAndGithub<Model, GithubModel> = Model & {
   converter: AdminFirestoreDataConverter<Model> & {
     fromGithub: (model: GithubModel) => Model;