Generate commit messages using Completion API

generate-commit-message.mjs

#!/bin/node
/*

How to use this shit?

1. Install llama.cpp
2. Download the completion DB from https://huggingface.co/
3. Start local server: `llama-server -m ~/Downloads/Qwen2.5-7B-Instruct-Q8_0.gguf`
4. Stage your diff changes and don't commit yet: `git add .`
5. Run this file `node generate-commit-message.mjs`

*/

import { execSync } from 'child_process'
import http from 'http'

const diff = execSync('git diff --staged').toString().trim();
const payload = JSON.stringify({
    messages: [
        { 
            role: "system",
            content: `Please write me Git commit message based on the diff given by user
            adhering to the following requirements:
            - Header: Start message title with appropriate emoji (Gitmoji);
            - Title should be imperative;
            - title and message separated by empty line
            - message body should describe the changes in the diff;
            - message uses bulleted lists if necessary.
            Please start answering to user with commit message already,
            without explanations, or citing code from the diff - just the commit message.
            Now the diff is this: ` + diff
        },
    ]
});

const options = {
    hostname: '127.0.0.1',
    port: 8080,
    path: '/v1/chat/completions',
    method: 'POST',
    headers: {
        'Content-type': 'application/json',
        'Content-Length': Buffer.byteLength(payload)
    }
}
const req = http.request(options, (res) => {
    let data = '';

    res.on('data', (chunk) => {
        data += chunk;
    });

    res.on('end', () => {
        let jsonResponse;
        try {
            jsonResponse = JSON.parse(data);
        } catch (error) {
            console.error('Error parsing JSON: ', data, error.message)
        }
        try {
            const answer = jsonResponse.choices[0].message.content;
            console.log(answer);
            process.exit(0);
        } catch (error) {
            console.error("cannot find the answer in response");
            process.exit(1);
        }
    });

    res.on('error', (error) => {
        console.error('Erro making a call to completion endpoint', error.message);
        process.exit(1);
    });
});

req.write(payload)
req.end();

generate-commit.mjs

import { spawn } from 'child_process';
import { execSync } from 'child_process';

// === CONFIG ===
const MODEL_PATH = '/Users/lape/Models/Qwen2.5-7B-Instruct-Q8_0.gguf';

// === SYSTEM PROMPT ===
const systemPrompt = `
Please write me a Git commit message based on the diff given by user
adhering to the following requirements:
- Header: Start message title with appropriate emoji (Gitmoji),
  in the same line as the rest of the title;
- Title should be imperative;
- Title and message should be separated by an empty line;
- Message body should describe the changes in the diff;
- Message uses bulleted lists if necessary.
Please start answering to user with commit message already,
without explanations, or citing any code from the diff – just the commit message.
`.trim();

// === LOAD DIFF FILE ===
let userPrompt;
const diff = execSync('git diff --staged').toString().trim();
userPrompt = diff;

// === CONSTRUCT CHATML PROMPT ===
const chatmlPrompt = `
<|im_start|>system
${systemPrompt}<|im_end|>
<|im_start|>user
${userPrompt}<|im_end|>
<|im_start|>assistant
`.trim();

// === SPAWN LLAMA-CLI SAFELY ===
const llama = spawn('llama-cli', [
  '--model', MODEL_PATH,
  '--n-predict', '-1',
  '--ctx-size', '6500',
  '--prompt', chatmlPrompt,
],
);

llama.stdout.on('data', (data) => {
  process.stdout.write(data);
  if (data.equals(Buffer.from([0x0a, 0x0a, 0x3e, 0x20]))) {
    console.log("EOM");
    process.exit(0);
  }
});

llama.stderr.on('data', (data) => {
  process.stderr.write(data);
});

llama.on('exit', (code) => {
  if (code !== 0) {
    console.error(`\n❌ llama-cli exited with code ${code}`);
  } else {

    console.error(`\n❌ llama-cli exited with code ${code}`);
  }
});