Option to update the PR comment

Author: oacik

action.yml

@@ -16,6 +16,10 @@ inputs:
     description: 'Set the GitHub token to have the action comment the coverage summary in the pull request. This token is provided by Actions, you do not need to create your own token. Optional. Default: ``'
   working-directory:
     description: 'The working directory containing the source files referenced in the LCOV files. Optional. Default: `./`'
+  update-comment:
+    description: Update the existing comment if it exists instead of creating a new one
+    required: false
+    default: false
 runs:
   using: 'node12'
   main: 'dist/main/index.js'

src/main.js

@@ -7,6 +7,10 @@ const lcovTotal = require("lcov-total");
 const os = require('os');
 const path = require('path');
 
+function commentIdentifier(workflowName) {
+	return `### [LCOV](https://github.com/marketplace/actions/report-lcov) of commit`
+}
+
 async function run() {
   try {
     await exec.exec('sudo apt-get install -y lcov');
@@ -15,6 +19,7 @@ async function run() {
     const coverageFilesPattern = core.getInput('coverage-files');
     const globber = await glob.create(coverageFilesPattern);
     const coverageFiles = await globber.glob();
+    const updateComment = core.getInput('update-comment');
 
     await genhtml(coverageFiles, tmpPath);
 
@@ -37,6 +42,33 @@ async function run() {
         body += `\n:no_entry: ${errorMessage}`;
       }
 
+      const updateGitHubComment = commentId =>
+          octokit.issues.updateComment({
+            repo: github.context.repo.repo,
+            owner: github.context.repo.owner,
+            comment_id: commentId,
+            body,
+          })
+
+      if (updateComment == "true") {
+        const issueComments = await octokit.issues.listComments({
+          repo: github.context.repo.repo,
+          owner: github.context.repo.owner,
+          issue_number: github.context.payload.pull_request.number,
+        })
+
+        const existingComment = issueComments.data.find(comment =>
+            comment.body.includes(commentIdentifier(process.env.GITHUB_WORKFLOW)),
+        )
+
+        if (existingComment) {
+          console.log('Update Comment ID: ' + existingComment.id);
+          await updateGitHubComment(existingComment.id);
+          return
+        }
+        console.log('Comment does not exist, create a new one');
+      }
+
       core.debug("Creating a comment in the PR.")
       await octokit.issues.createComment({
         owner: github.context.repo.owner,