Changelog

Keep a Changelog library for Node & Deno

Deno package to parse and generate changelogs following the keepachangelog format.

Usage in Node

1import { parser } from "keep-a-changelog";
2import fs from "fs";
3
4//Parse a changelog file
5const changelog = parser(fs.readFileSync("CHANGELOG.md", "UTF-8"));
6
7//Generate the new changelog string
8console.log(changelog.toString());

Usage in Deno

1import { parser } from "https://deno.land/x/changelog@v2.2.1/mod.ts";
2
3//Parse a changelog file
4const changelog = parser(await Deno.readTextFile("CHANGELOG.md"));
5
6//Generate the new changelog string
7console.log(changelog.toString());

Create a new changelog

1import {
2  Changelog,
3  Release,
4} from "https://deno.land/x/changelog@v2.2.1/mod.ts";
5
6const changelog = new Changelog("My project")
7  .addRelease(
8    new Release("0.1.0", "2017-12-06")
9      .added("New awesome feature")
10      .added("New other awesome feature")
11      .fixed("Bug #3")
12      .removed("Drop support for X"),
13  )
14  .addRelease(
15    new Release("0.2.0", "2017-12-09")
16      .security("Fixed security vulnerability")
17      .deprecated("Feature X is deprecated"),
18  );
19
20console.log(changelog.toString());

Custom output format

By default, the output format of the markdown is "compact", that removes the space after the headings. You can change it to follow the markdownlint rules:

1const changelog = new Changelog();
2changelog.format = "markdownlint";

Custom bullet style

By default, the bullet style of the markdown is "-". You can change it to use other styles of bullet points:

1const changelog = new Changelog();
2changelog.bulletStyle = "*";

Custom tag names

By default, the tag names are v + version number. For example, the tag for the version 2.4.9 is v2.4.9. To change this behavior, set a new tagNameBuilder:

1const changelog = new Changelog();
2changelog.tagNameBuilder = (release) => `version-${release.version}`;

Custom compare links

By default, compare links are build compliant with GitHub format. To change this behavior, set a new compareLinkBuilder:

1const changelog = new Changelog();
2changelog.url = "https://bitbucket.org/oscarotero/keep-a-changelog";
3changelog.compareLinkBuilder = (previous, release) =>
4  `${this.url}/branches/compare/${release.version}%0D${previous.version}`;

Custom Change Types

By default and according to the keepachangelog format, the change types are Added, Changed, Deprecated, Removed, Fixed, and Security.

In case you'd like add another type, you need to extend the Release class to support new types. Additionally, you have to tell the parser that it should create instances of your new extended Release in order to parse your changelog correctly.

For example, we would like to add a type Maintenance. Extend the provided Release class:

1class CustomRelease extends Release {
2  constructor(version, date, description) {
3    super(version, date, description);
4    // add whatever types you want - in lowercase
5    const newChangeTypes = [
6      ["maintenance", []],
7    ];
8
9    this.changes = new Map([...this.changes, ...newChangeTypes]);
10  }
11  // for convenience, add a new method to add change of type 'maintanance'
12  maintenance(change) {
13    return this.addChange("maintenance", change);
14  }
15}

And once you want to use the parser:

1const releaseCreator = (ver, date, desc) => new CustomRelease(ver, date, desc);
2const changelog = parser(changelogTextContent, { releaseCreator });

Cli

This library provides the changelog command to normalize the changelog format. It reads the CHANGELOG.md file and override it with the new format:

Install the library as script

Deno:

1deno install --global --allow-read --allow-write -fr --name changelog https://deno.land/x/changelog/bin.ts

Node:

1npm install keep-a-changelog -g

Run the script:

1changelog

To use other file name:

1changelog --file=History.md

To generate an empty new CHANGELOG.md file:

1changelog --init

You can release automatically the latest "Unreleased" version:

1changelog --release

If your "Unreleased" section has no version, you can specify it as an argument:

1changelog --release 2.0.0

Print the latest released version:

1changelog --latest-release
2> 2.0.0

Print the latest release:

1changelog --latest-release-full
2## 2.6.1 - 2025-02-24
3### Fixed
4- NPM publishing [#55], [#56].

See available options:

1changelog --help