add comment deduplication feature

This feature will allow to create a comment and perform a deduplication
of previous comments that match a deduplication key

action.yml

@@ -15,6 +15,9 @@ inputs:
   number:
     description: The number of the issue or pull request.
     required: false
+  deduplicate:
+    description: Value to deduplicate comment
+    required: false
 runs:
   using: node12
   main: dist/index.js

src/main.ts

@@ -5,6 +5,7 @@ async function run(): Promise<void> {
   try {
     const githubToken = core.getInput('github_token', { required: true });
     const body = core.getInput('body', { required: true });
+    const deduplicate = core.getInput('deduplicate', { required: false });
 
     const octokit = github.getOctokit(githubToken);
 
@@ -18,6 +19,23 @@ async function run(): Promise<void> {
         ? github.context.issue.number
         : parseInt(core.getInput('number'));
 
+    if (deduplicate) {
+      const comments = await octokit.issues.listComments({
+        owner,
+        repo,
+        issue_number: number
+      })
+      const comment_ids = comments.filter(comment => comment.body.includes(deduplicate))
+      for (const comment_id of comment_ids) {
+        await octokit.issues.deleteComment({
+          owner,
+          repo,
+          issue_number: number,
+          comment_id,
+        })
+      }
+    }
+
     await octokit.issues.createComment({
       owner,
       repo,