conventional-changelog-lite

Parse Conventional Commits from raw git log text and render a CHANGELOG.md section with a suggested semver bump. Strict TypeScript, zero runtime dependencies.

Why

Most changelog generators want to shell out to git themselves. This one doesn't — you supply the log text (from whatever git command, CI log artifact, or file you like), and it hands back structured commits, grouped sections, and a bump suggestion. That keeps it usable in sandboxes, CI systems without a git binary, and anywhere else you don't want a library running child processes on your behalf.

Quickstart

import { parseCommits, suggestBump, renderChangelog, gitLogCommand } from "conventional-changelog-lite";
import { execSync } from "node:child_process";

const logText = execSync(gitLogCommand()).toString();
const commits = parseCommits(logText);

console.log(suggestBump(commits)); // "major" | "minor" | "patch" | "none"

console.log(
  renderChangelog(commits, {
    version: "2.0.0",
    repo: "your-org/your-repo",
    previousVersion: "1.4.0",
  })
);

API

gitLogCommand(): string

Returns the exact git log command this parser expects as input: git log --pretty=format:'commit %H%n%B%n===END==='. The parser also tolerates plain git log --pretty=%B output and default git log output as fallbacks.

parseCommits(logText: string): ParsedCommit[]

Splits log text into commit records and parses each as a Conventional Commit. Non-conforming commits are returned with type: "other" rather than dropped.

groupByType(commits): Record<CommitType, ParsedCommit[]>

Buckets parsed commits by type.

suggestBump(commits): "major" | "minor" | "patch" | "none"

Any breaking change → "major". Else any feat → "minor". Else any fix/perf → "patch". Else "none".

renderChangelog(commits, options): string

Renders a markdown changelog section. options.repo + options.previousVersion add a GitHub compare link to the heading and commit links.

Types

ParsedCommit, CommitType, SemverBump, RenderOptions — all exported.

Limits

• Text-based parsing only — it does not run git for you and cannot validate that the log text is complete or well-formed.
• The default marker-based split (===END===) is the most reliable format; plain git log output without markers is parsed best-effort.
• Scope detection assumes the standard type(scope): subject header shape; unusual header formats fall back to type: "other".

Part of the ferrow-toolkit collection · Sponsored by Ferrow