feat: add comment-body output

Author: rzzf

action.yml

@@ -50,6 +50,10 @@ inputs:
     description: 'The column and direction to sort the results by. The format is "column:direction", where column is one of "Filename", "Size", or "Change" and direction is "asc" or "desc". For example, "Size:desc" sorts the table by file size in descending order.'
     default: 'Filename:asc'
 
+outputs:
+  comment-body:
+    description: 'The full Markdown body the action posts to the PR, including the size report, footer, and hidden marker comment: "<!-- compressed-size-action -->" or "<!-- compressed-size-action::KEY -->" when comment-key is set.'
+
 runs:
   using: 'node24'
   main: 'index.js'

package-lock.json

@@ -8,7 +8,7 @@
   },
   "license": "MIT",
   "devDependencies": {
-    "@actions/core": "^1.2.6",
+    "@actions/core": "^1.10.0",
     "@actions/exec": "^1.0.4",
     "@actions/github": "^4.0.0",
     "@babel/core": "^7.29.0",

package.json

@@ -1,4 +1,4 @@
-import { getInput, setFailed, startGroup, endGroup, debug } from '@actions/core';
+import { getInput, setFailed, setOutput, startGroup, endGroup, debug } from '@actions/core';
 import { context, getOctokit } from '@actions/github';
 import { exec } from '@actions/exec';
 import { SizePlugin } from '@rschristian/size-plugin';
@@ -167,9 +167,12 @@ async function run(octokit, context, token) {
 		...commentInfo,
 		body:
 			markdownDiff +
-			`\n\n<a href="https://github.com/preactjs/compressed-size-action"><sub>compressed-size-action${commentKey ? `::${commentKey}` : ''}</sub></a>`
+			`\n\n<a href="https://github.com/preactjs/compressed-size-action"><sub>compressed-size-action${commentKey ? `::${commentKey}` : ''}</sub></a>` +
+			`\n<!-- compressed-size-action${commentKey ? `::${commentKey}` : ''} -->`
 	};
 
+	setOutput('comment-body', comment.body);
+
 	if (context.eventName !== 'pull_request' && context.eventName !== 'pull_request_target') {
 		console.log('No PR associated with this action run. Not posting a check or comment.');
 		outputRawMarkdown = false;