Make reassign reviewer only work for core contributors (GoogleCloudPlatform#13361)

Author: trodge

.ci/magician/cmd/reassign_reviewer.go

@@ -32,14 +32,15 @@ var reassignReviewerCmd = &cobra.Command{
 
 	The command expects the following PR details as arguments:
 	1. PR_NUMBER
-	2. REVIEWER (optional)
+	2. COMMENT_AUTHOR
+	3. REVIEWER (optional)
 
 
 	It then performs the following operations:
 	1. Updates the reviewer comment to reflect the new primary reviewer.
 	2. Requests a review from the new primary reviewer.
 	`,
-	Args: cobra.MinimumNArgs(1),
+	Args: cobra.MinimumNArgs(2),
 	RunE: func(cmd *cobra.Command, args []string) error {
 		prNumber := args[0]
 		fmt.Println("PR Number: ", prNumber)
@@ -49,9 +50,15 @@ var reassignReviewerCmd = &cobra.Command{
 			return fmt.Errorf("did not provide GITHUB_TOKEN environment variable")
 		}
 		gh := github.NewClient(githubToken)
+
+		author := args[1]
+		if gh.GetUserType(author) != github.CoreContributorUserType {
+			return fmt.Errorf("comment author is not a core contributor")
+		}
+
 		var newPrimaryReviewer string
-		if len(args) > 1 {
-			newPrimaryReviewer = args[1]
+		if len(args) > 2 {
+			newPrimaryReviewer = args[2]
 		}
 		return execReassignReviewer(prNumber, newPrimaryReviewer, gh)
 	},

.github/workflows/reassign-reviewer.yml

@@ -42,4 +42,4 @@ jobs:
           go build .
       - name: Run command
         if: steps.read-comment.outputs.match != ''
-        run: .ci/magician/magician reassign-reviewer ${{ github.event.issue.number }} ${{ steps.read-comment.outputs.group1 }}
+        run: .ci/magician/magician reassign-reviewer ${{ github.event.issue.number }} ${{ github.event.comment.user.login }} ${{ steps.read-comment.outputs.group1 }}