fix: remove auto request reviewers

The auto request reviewers feature never really worked well. The problem
is that it tries to copy the current open review requests, but when a PR
is merged, most of those reviews have already been completed. When
completed, they are no longer in the review request list.

The feature became problematic for users when using a bot user (PAT)
that does not have admin rights to the repository. Those rights are
necessary to request reviewers in some repos.

Multiple solutions were possible, but as this feature doesn't behave
as wanted, and might even be unexpected to some users (breaking the
principle of least astonishment), I believe it should simply be removed.
We can always re-introduce it with a configuration option at a later
time.

src/backport.ts

@@ -1,11 +1,7 @@
 import * as core from "@actions/core";
 import dedent from "dedent";
 
-import {
-  CreatePullRequestResponse,
-  RequestReviewersResponse,
-  PullRequest,
-} from "./github";
+import { CreatePullRequestResponse, PullRequest } from "./github";
 import { GithubApi } from "./github";
 import * as git from "./git";
 import * as utils from "./utils";
@@ -56,7 +52,6 @@ export class Backport {
       const headref = mainpr.head.sha;
       const baseref = mainpr.base.sha;
       const labels = mainpr.labels;
-      const reviewers = mainpr.requested_reviewers?.map((r) => r.login) ?? [];
 
       console.log(
         `Detected labels on PR: ${labels.map((label) => label.name)}`
@@ -171,27 +166,6 @@ export class Backport {
           }
           const new_pr = new_pr_response.data;
 
-          const review_response = await this.github.requestReviewers({
-            owner,
-            repo,
-            pull_number: new_pr.number,
-            reviewers,
-          });
-          if (review_response.status != 201) {
-            console.error(JSON.stringify(review_response));
-            const message = this.composeMessageForRequestReviewersFailed(
-              review_response,
-              target
-            );
-            await this.github.createComment({
-              owner,
-              repo,
-              issue_number: pull_number,
-              body: message,
-            });
-            continue;
-          }
-
           const message = this.composeMessageForSuccess(new_pr.number, target);
           await this.github.createComment({
             owner,
@@ -285,18 +259,6 @@ export class Backport {
                 (see action log for full response)`;
   }
 
-  private composeMessageForRequestReviewersFailed(
-    response: RequestReviewersResponse,
-    target: string
-  ): string {
-    return dedent`${this.composeMessageForSuccess(response.data.number, target)}
-                But, request reviewers was rejected with status ${
-                  response.status
-                }.
-
-                (see action log for full response)`;
-  }
-
   private composeMessageForSuccess(pr_number: number, target: string) {
     return dedent`Successfully created backport PR #${pr_number} for \`${target}\`.`;
   }

src/test/backport.test.ts

@@ -110,7 +110,7 @@ describe("the backport action", () => {
           config.pwd
         );
       });
-      it("creates a pull request and requests reviewers", async () => {
+      it("creates a pull request", async () => {
         mockedGit.push.mockResolvedValue(0);
         await backport.run();
         expect(
@@ -124,14 +124,6 @@ describe("the backport action", () => {
           body: `Backport of #1347 to \`stable/0.25\`.`,
           maintainer_can_modify: true,
         });
-        expect(
-          mockedDefaultGithubWithBackportLabel.requestReviewers
-        ).toHaveBeenCalledWith({
-          owner: "octocat",
-          repo: "Hello-World",
-          pull_number: 9000,
-          reviewers: ["other_user"],
-        });
       });
     });
   });