fix(File): Don’t exceed the max allowed length for issue titles (256 characters) (#69)

Fixes #61

Author: smockle

.github/actions/file/src/openIssue.ts

@@ -3,12 +3,28 @@ import type { Finding } from './types.d.js';
 import * as url from 'node:url'
 const URL = url.URL;
 
+/** Max length for GitHub issue titles */
+const GITHUB_ISSUE_TITLE_MAX_LENGTH = 256;
+
+/**
+ * Truncates text to a maximum length, adding an ellipsis if truncated.
+ * @param text Original text
+ * @param maxLength Maximum length of the returned text (including ellipsis)
+ * @returns Either the original text or a truncated version with an ellipsis
+ */
+function truncateWithEllipsis(text: string, maxLength: number): string {
+  return text.length > maxLength ? text.slice(0, maxLength - 1) + '…' : text;
+}
+
 export async function openIssue(octokit: Octokit, repoWithOwner: string, finding: Finding) {
   const owner = repoWithOwner.split('/')[0];
   const repo = repoWithOwner.split('/')[1];
 
   const labels = [`${finding.scannerType} rule: ${finding.ruleId}`, `${finding.scannerType}-scanning-issue`];
-  const title = `Accessibility issue: ${finding.problemShort[0].toUpperCase() + finding.problemShort.slice(1)} on ${new URL(finding.url).pathname}`;
+  const title = truncateWithEllipsis(
+    `Accessibility issue: ${finding.problemShort[0].toUpperCase() + finding.problemShort.slice(1)} on ${new URL(finding.url).pathname}`,
+    GITHUB_ISSUE_TITLE_MAX_LENGTH
+  );
   const solutionLong = finding.solutionLong
     ?.split("\n")
     .map((line) =>