feat: allow inheriting or overwriting assignee

action.yml

@@ -27,7 +27,7 @@ inputs:
     pr-assignee:
         description:
             '(optional) User ID to be assigned to the created PR. Will use the
-            author of the original PR by default'
+            assignee of the original PR by default'
         required: false
         default: ''
     pr-labels:

src/main.ts

@@ -1,7 +1,7 @@
 import * as core from '@actions/core'
 import * as github from '@actions/github'
 import { Label, PullRequest } from '@octokit/webhooks-types'
-import { addLabels, createPullRequest } from './pr'
+import { addAssignee, addLabels, createPullRequest } from './pr'
 import {
     cherryPickChangesToNewBranch,
     configureGitUser,
@@ -37,9 +37,9 @@ export async function run(): Promise<void> {
         const githubToken = core.getInput('pr-creator-token')
         const submoduleName = core.getInput('submodule-name')
         let prAssignee = core.getInput('pr-assignee')
-        if (prAssignee === '') {
-            // Use the author of the original PR as the assignee of the cherry-pick
-            prAssignee = mergedPR.user.login
+        if (prAssignee === '' && mergedPR.assignee != null) {
+            // Use the assignee of the original PR as the assignee of the cherry-pick
+            prAssignee = mergedPR.assignee.login
         }
         const labelsInput = core.getInput('pr-labels')
         let addedLabels: string[] = []
@@ -112,6 +112,8 @@ export async function run(): Promise<void> {
             inheritedLabels.concat(addedLabels)
         )
 
+        await addAssignee(githubToken, resultPrNumber, prAssignee)
+
         core.setOutput('pr-number', resultPrNumber)
     } catch (error) {
         // Fail the workflow run if an error occurs

src/pr.ts

@@ -55,3 +55,23 @@ export async function addLabels(
         labels: labelsToAdd
     })
 }
+
+export async function addAssignee(
+    githubToken: string,
+    issueNumber: number,
+    assigneeUserName: string
+): Promise<void> {
+    if (assigneeUserName.length === 0) {
+        console.info('Skipping addition of assignee, as passed value is empty')
+        return
+    }
+    const octokit = github.getOctokit(githubToken)
+    const repoOwner = github.context.repo.owner
+    const repoName = github.context.repo.repo
+    await octokit.rest.issues.addAssignees({
+        owner: repoOwner,
+        repo: repoName,
+        issue_number: issueNumber,
+        assignees: [assigneeUserName]
+    })
+}