Update existing comment if found

index.js

@@ -98,11 +98,28 @@ function tmpl(t, o) {
 
 async function exitWithError(exitType, octokit, shouldAddComment, message) {
   if (shouldAddComment) {
-    await octokit.rest.issues.createComment({
+    const matchToken = `<!-- reqlabelmessage -->`;
+    // Is there an existing comment?
+    const { data: existing } = await octokit.rest.issues.listComments({
       ...github.context.repo,
       issue_number: github.context.issue.number,
-      body: message,
     });
+
+    const generatedComment = existing.find((c) => c.body.includes(matchToken));
+
+    const params = {
+      ...github.context.repo,
+      issue_number: github.context.issue.number,
+      body: `${matchToken} ${message}`,
+    };
+
+    // If so, update it
+    let method = "createComment";
+    if (generatedComment) {
+      method = "updateComment";
+      params.comment_id = generatedComment.id;
+    }
+    await octokit.rest.issues[method](params);
   }
 
   core.setOutput("status", "failure");