Chore: Add release script (#25)

CONTRIBUTING.md

@@ -19,3 +19,13 @@ npm test
 This is an [ESLint](http://eslint.org) plugin. Documentation for the APIs that it uses can be found on ESLint's [Working with Plugins](http://eslint.org/docs/developer-guide/working-with-plugins) page.
 
 This plugin is used to lint itself. The style is checked when `npm test` is run, and the build will fail if there are any linting errors. You can use `npm run lint -- --fix` to fix some linting errors. To run the tests without running the linter, you can use `node_modules/.bin/mocha`.
+
+## Publishing
+
+```bash
+node build/release.js
+git push --follow-tags
+npm publish
+```
+
+`build/release.js` will generate a commit and tag like https://github.com/prettier/eslint-plugin-prettier/commit/56873bf2.

build/release.js

@@ -0,0 +1,97 @@
+'use strict';
+
+const fs = require('fs');
+const childProcess = require('child_process');
+const path = require('path');
+const semver = require('semver');
+const moment = require('moment');
+const PACKAGE_JSON_PATH = path.join(process.cwd(), 'package.json');
+const CHANGELOG_PATH = path.join(process.cwd(), 'CHANGELOG.md');
+const packageFile = require(PACKAGE_JSON_PATH);
+
+function exec(command) {
+  return childProcess.execSync(command).toString().slice(0, -1);
+}
+
+const githubRepoUrl = exec('git config --get remote.origin.url').replace(
+  /\.git$/,
+  ''
+);
+
+function updatePackageJson(version) {
+  fs.writeFileSync(
+    PACKAGE_JSON_PATH,
+    JSON.stringify(Object.assign({}, packageFile, { version }), null, 2) + '\n'
+  );
+}
+
+function updateChangelog(newText) {
+  fs.writeFileSync(CHANGELOG_PATH, newText);
+}
+
+function createGitCommit(version) {
+  exec(
+    `git commit -am 'Build: update package.json and changelog for v${version}'`
+  );
+}
+
+function createGitTag(version) {
+  exec(`git tag v${version}`);
+}
+
+function getCommitSubject(commitHash) {
+  return exec(`git --no-pager show -s --oneline --format=%s ${commitHash}`);
+}
+
+function getAbbreviatedCommitHash(commitHash) {
+  return exec(`git --no-pager show -s --oneline --format=%h ${commitHash}`);
+}
+
+function getCommitLink(commitHash) {
+  return `[${getAbbreviatedCommitHash(commitHash)}](${githubRepoUrl}/commit/${commitHash})`;
+}
+
+function replaceIssueLinks(message) {
+  return message.replace(/#(\d+)/g, `[#$1](${githubRepoUrl}/issues/$1)`);
+}
+
+const commitHashes = exec(`git log --format=%H v${packageFile.version}...HEAD`)
+  .split('\n')
+  .filter(hash => hash);
+
+if (!commitHashes.length) {
+  throw new RangeError('No commits since last release');
+}
+
+const commitSubjects = commitHashes.map(getCommitSubject);
+let newVersion;
+
+if (commitSubjects.some(subject => subject.startsWith('Breaking'))) {
+  newVersion = semver.inc(packageFile.version, 'major');
+} else if (
+  commitSubjects.some(
+    subject => subject.startsWith('Update') || subject.startsWith('New')
+  )
+) {
+  newVersion = semver.inc(packageFile.version, 'minor');
+} else {
+  newVersion = semver.inc(packageFile.version, 'patch');
+}
+
+const newChangelogHeader = `## v${newVersion} (${moment
+  .utc()
+  .format('YYYY[-]MM[-]DD')})`;
+const commitLines = commitHashes.map(
+  hash =>
+    `* ${replaceIssueLinks(getCommitSubject(hash))} (${getCommitLink(hash)})`
+);
+const oldChangelog = fs.readFileSync(CHANGELOG_PATH).toString();
+const newChangelog = oldChangelog.replace(
+  /^(# Changelog\n\n)/,
+  `$1${newChangelogHeader}\n\n${commitLines.join('\n')}\n\n`
+);
+
+updatePackageJson(newVersion);
+updateChangelog(newChangelog);
+createGitCommit(newVersion);
+createGitTag(newVersion);

package.json

@@ -40,7 +40,9 @@
     "eslint-plugin-eslint-plugin": "^0.7.1",
     "eslint-plugin-node": "^4.2.2",
     "mocha": "^3.1.2",
-    "prettier": "^1.3.1"
+    "moment": "^2.18.1",
+    "prettier": "^1.3.1",
+    "semver": "^5.3.0"
   },
   "engines": {
     "node": ">=4.0.0"

yarn.lock

@@ -727,6 +727,10 @@ mocha@^3.1.2:
     mkdirp "0.5.1"
     supports-color "3.1.2"
 
+moment@^2.18.1:
+  version "2.18.1"
+  resolved "https://registry.yarnpkg.com/moment/-/moment-2.18.1.tgz#c36193dd3ce1c2eed2adb7c802dbbc77a81b1c0f"
+
 [email protected]:
   version "0.7.2"
   resolved "https://registry.yarnpkg.com/ms/-/ms-0.7.2.tgz#ae25cf2512b3885a1d95d7f037868d8431124765"
@@ -901,7 +905,7 @@ rx-lite@^3.1.2:
   version "3.1.2"
   resolved "https://registry.yarnpkg.com/rx-lite/-/rx-lite-3.1.2.tgz#19ce502ca572665f3b647b10939f97fd1615f102"
 
-[email protected]:
+[email protected], semver@^5.3.0:
   version "5.3.0"
   resolved "https://registry.yarnpkg.com/semver/-/semver-5.3.0.tgz#9b2ce5d3de02d17c6012ad326aa6b4d0cf54f94f"