smart-git-commit/suggestCommit/buildPrompt.js

AI-powered smart commit message generator for Git diffs.

export default function buildPrompt(fileChanges) {
  let prompt =
    "You are a helpful AI that writes conventional git commit messages.\n\n";

  prompt +=
    "Based on the following code changes, suggest a concise, single-line commit message following the Conventional Commits format:\n";
  prompt += "Format: <type>(<scope>): <short description>\n";
  prompt +=
    "Where <type> is one of: feat, fix, chore, refactor, docs, test, ci, build\n\n";

  const maxFiles = 10;
  const maxLinesPerFile = 2;

  fileChanges.slice(0, maxFiles).forEach((file) => {
    prompt += `File: ${file.file} | Change: ${file.changeType}\n`;

    const sampleAdditions = file.additions.slice(0, maxLinesPerFile);
    const sampleDeletions = file.deletions.slice(0, maxLinesPerFile);

    if (sampleAdditions.length > 0) {
      prompt += `+ ${sampleAdditions.join("\n+ ")}\n`;
    }
    if (sampleDeletions.length > 0) {
      prompt += `- ${sampleDeletions.join("\n- ")}\n`;
    }

    prompt += "\n";
  });

  if (fileChanges.length > maxFiles) {
    prompt += `...and ${fileChanges.length - maxFiles} more files changed.\n`;
  }

  prompt +=
    "\nRespond ONLY with the commit message in the correct Conventional Commits format.";
  return prompt;
}