Append Jira issue number to every commit

prepare-commit-msg

#!/usr/bin/env node
const { exec } = require('child_process');
const { readFile, writeFile } = require('fs');
const { EOL } = require('os');

const CURRENT_BRANCH_JIRA_ISSUE_EXP = /[a-zA-Z]+[-][0-9]+/;
const messageFile = process.argv[2];

/**
 * We need the message file to append.
 * If we can not find it -> abort.
 */
if(!/COMMIT_EDITMSG/i.test(messageFile)) {
  return process.exit(0);
}

exec('git rev-parse --abbrev-ref HEAD', (err, stdout) => {
  // Command will fail if there are no commits yet.
  if (err) { return process.exit(0); }

  // Extract Jira issue number from current branch.
  const issue = (CURRENT_BRANCH_JIRA_ISSUE_EXP.exec(stdout)||[])[0];

  // Could not find an issue number.
  if (!issue) { return process.exit(0); }

  // Read commit message file
  readFile(messageFile, (err, data) => {
    if (err) { return process.exit(0) };

    // Append issue number to file content and write back.
    writeFile(messageFile, `${data}${EOL}${EOL}Issue: ${issue.toUpperCase()}`, () => {
      process.exit(0);
    });
  });
});

Make sure it is executable -> chmod u+x .git/hooks/prepare-commit-msg