#!/usr/bin/env node
/**
* Auto-generate Changesets from conventional commits
*
* Analyzes commits since last release and creates changeset files.
* Every merge to main triggers a release.
*
* Version bump rules for 0.x.x releases:
* - Breaking changes (feat!, BREAKING CHANGE) â minor bump (0.x.0)
* - All other commits â patch bump (0.0.x)
*/
import { execSync } from 'node:child_process';
import { randomBytes } from 'node:crypto';
import { existsSync, readdirSync, writeFileSync, readFileSync } from 'node:fs';
import { join } from 'node:path';
interface ParsedCommit {
type: string;
scope?: string;
breaking: boolean;
message: string;
body?: string;
hash: string;
}
function exec(command: string): string {
try {
return execSync(command, { encoding: 'utf-8' }).trim();
} catch (_error) {
return '';
}
}
function getPackageName(): string {
const pkgPath = join(process.cwd(), 'package.json');
const pkg = JSON.parse(readFileSync(pkgPath, 'utf-8'));
return pkg.name;
}
function getCommitsSinceLastRelease(): string[] {
const lastTag = exec('git describe --tags --abbrev=0 2>/dev/null');
let range: string;
if (lastTag) {
range = `${lastTag}..HEAD`;
} else {
range = 'HEAD';
}
const commits = exec(
`git log ${range} --pretty=format:"%H|||%s|||%b" --no-merges`,
);
if (!commits) return [];
return commits.split('\n').filter(Boolean);
}
function parseConventionalCommit(commitLine: string): ParsedCommit | null {
const [hash, subject, body] = commitLine.split('|||');
if (!subject) {
console.log(
`Skipping commit with empty subject: ${hash?.substring(0, 7) || 'unknown'}`,
);
return null;
}
const match = subject.match(/^(\w+)(?:\(([^)]+)\))?(!)?:\s*(.+)$/);
if (!match) {
console.log(`Skipping non-conventional commit: ${subject}`);
return null;
}
const [, type, scope, breaking, message] = match;
const hasBreakingInBody = body?.includes('BREAKING CHANGE') || false;
return {
type,
scope,
breaking: !!breaking || hasBreakingInBody,
message: message.trim(),
body,
hash: hash.substring(0, 7),
};
}
function determineVersionBump(
commits: ParsedCommit[],
): 'major' | 'minor' | 'patch' {
const hasBreaking = commits.some((c) => c.breaking);
return hasBreaking ? 'minor' : 'patch';
}
function generateChangesetContent(
packageName: string,
commits: ParsedCommit[],
bump: 'major' | 'minor' | 'patch',
): string {
const breaking = commits.filter((c) => c.breaking);
const features = commits.filter((c) => c.type === 'feat' && !c.breaking);
const fixes = commits.filter((c) => c.type === 'fix' && !c.breaking);
const other = commits.filter(
(c) => !c.breaking && c.type !== 'feat' && c.type !== 'fix',
);
let content = `---\n`;
content += `"${packageName}": ${bump}\n`;
content += `---\n\n`;
if (breaking.length > 0) {
content += `### Breaking Changes\n\n`;
breaking.forEach((c) => {
content += `- ${c.message}${c.scope ? ` (${c.scope})` : ''}\n`;
});
content += `\n`;
}
if (features.length > 0) {
content += `### Features\n\n`;
features.forEach((c) => {
content += `- ${c.message}${c.scope ? ` (${c.scope})` : ''}\n`;
});
content += `\n`;
}
if (fixes.length > 0) {
content += `### Bug Fixes\n\n`;
fixes.forEach((c) => {
content += `- ${c.message}${c.scope ? ` (${c.scope})` : ''}\n`;
});
content += `\n`;
}
if (other.length > 0) {
content += `### Other Changes\n\n`;
other.forEach((c) => {
content += `- ${c.type}: ${c.message}${c.scope ? ` (${c.scope})` : ''}\n`;
});
}
return `${content.trim()}\n`;
}
function hasExistingChangesets(): boolean {
const changesetDir = join(process.cwd(), '.changeset');
if (!existsSync(changesetDir)) return false;
const files = readdirSync(changesetDir);
return files.some(
(f) => f.endsWith('.md') && f !== 'README.md' && f !== 'config.json',
);
}
function main() {
console.log('đ Checking for conventional commits...');
if (hasExistingChangesets()) {
console.log('â
Existing changesets found, skipping auto-generation');
return;
}
const commitLines = getCommitsSinceLastRelease();
if (commitLines.length === 0) {
console.log('âšī¸ No commits found since last release');
return;
}
console.log(`đ Analyzing ${commitLines.length} commits...`);
const parsedCommits = commitLines
.map(parseConventionalCommit)
.filter((c): c is ParsedCommit => c !== null);
if (parsedCommits.length === 0) {
console.log('âšī¸ No conventional commits found');
return;
}
const packageName = getPackageName();
const bump = determineVersionBump(parsedCommits);
console.log(`đĻ Version bump: ${bump}`);
console.log(` - ${parsedCommits.length} conventional commits`);
console.log(
` - ${parsedCommits.filter((c) => c.breaking).length} breaking changes`,
);
const changesetId = randomBytes(8).toString('hex');
const changesetPath = join(
process.cwd(),
'.changeset',
`auto-${changesetId}.md`,
);
const changesetContent = generateChangesetContent(packageName, parsedCommits, bump);
writeFileSync(changesetPath, changesetContent);
console.log(`â
Generated changeset: .changeset/auto-${changesetId}.md`);
console.log('');
console.log('Changeset content:');
console.log('---');
console.log(changesetContent);
console.log('---');
}
main();
