[WIP] Add rule for closing new pull requests to starter repos

peril.settings.json

@@ -15,6 +15,15 @@
     "repos": {
         "gatsbyjs/gatsby" : {
             "pull_request": ["gatsbyjs/peril-gatsbyjs@rules/validate-yaml.ts"]
+        },
+        "gatsbyjs/gatsby-starter-default" : {
+            "pull_request.opened": ["gatsbyjs/peril-gatsbyjs@rules/pull-request-on-starter.ts"]
+        },
+        "gatsbyjs/gatsby-starter-hello-world" : {
+            "pull_request.opened": ["gatsbyjs/peril-gatsbyjs@rules/pull-request-on-starter.ts"]
+        },
+        "gatsbyjs/gatsby-starter-blog" : {
+            "pull_request.opened": ["gatsbyjs/peril-gatsbyjs@rules/pull-request-on-starter.ts"]
         }
     },
     "tasks": {

rules/pull-request-on-starter.ts

@@ -0,0 +1,39 @@
+import { danger, markdown } from "danger"
+
+// TODO: Improve comment
+export const comment = (username: string) => `
+Hey, @${username}
+
+Thank you for your pull request!
+
+ We've moved all our starters over to https://github.com/gatsbyjs/gatsby. Please reopen this there. 
+
+Thanks again!
+`
+
+export const closePullRequestAndComment = async () => {
+  const gh = danger.github
+  const api = gh.api
+
+  // Details about the repo.
+  const owner = gh.thisPR.owner
+  const repo = gh.thisPR.repo
+  const number = gh.thisPR.number
+
+  // Details about the collaborator.
+  const username = gh.pr.user.login
+
+  // Leave a comment redirecting the collaborator to the monorepo
+  markdown(comment(username))
+  // Close this pull request
+  await api.pullRequests.update({
+    owner,
+    repo,
+    number,
+    state: "closed",
+  })
+}
+
+export default async () => {
+  await closePullRequestAndComment()
+}

tests/pull-request-on-starter.test.ts

@@ -0,0 +1,47 @@
+jest.mock("danger", () => jest.fn())
+import * as danger from "danger"
+
+const dm = danger as any
+
+import {
+  closePullRequestAndComment,
+  comment,
+} from "../rules/pull-request-on-starter"
+
+beforeEach(() => {
+  dm.danger = {
+    github: {
+      thisPR: {
+        owner: "gatsbyjs",
+        repo: "peril-gatsbyjs",
+        number: 1,
+      },
+      pr: {
+        user: {
+          login: "someUser",
+        },
+      },
+      api: {
+        pullRequests: {
+          update: jest.fn(),
+        },
+      },
+    },
+  }
+  dm.markdown = jest.fn()
+})
+
+describe("an opened pull request", () => {
+  it("was closed with a comment", async () => {
+    await closePullRequestAndComment()
+
+    expect(dm.danger.github.api.pullRequests.update).toBeCalledWith({
+      owner: "gatsbyjs",
+      repo: "peril-gatsbyjs",
+      number: 1,
+      state: "closed",
+    })
+
+    expect(dm.markdown).toBeCalledWith(comment("someUser"))
+  })
+})