Changelog

Keep a Changelog library for Node & Deno

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

Usage in Node

import { parser } from "keep-a-changelog";
import fs from "fs";

//Parse a changelog file
const changelog = parser(fs.readFileSync("CHANGELOG.md", "UTF-8"));

//Generate the new changelog string
console.log(changelog.toString());

Usage in Deno

import { parser } from "https://deno.land/x/changelog@v2.2.1/mod.ts";

//Parse a changelog file
const changelog = parser(await Deno.readTextFile("CHANGELOG.md"));

//Generate the new changelog string
console.log(changelog.toString());

Create a new changelog

import {
  Changelog,
  Release,
} from "https://deno.land/x/changelog@v2.2.1/mod.ts";

const changelog = new Changelog("My project")
  .addRelease(
    new Release("0.1.0", "2017-12-06")
      .added("New awesome feature")
      .added("New other awesome feature")
      .fixed("Bug #3")
      .removed("Drop support for X"),
  )
  .addRelease(
    new Release("0.2.0", "2017-12-09")
      .security("Fixed security vulnerability")
      .deprecated("Feature X is deprecated"),
  );

console.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:

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

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:

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

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

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

class CustomRelease extends Release {
  constructor(version, date, description) {
    super(version, date, description);
    // add whatever types you want - in lowercase
    const newChangeTypes = [
      ["maintenance", []],
    ];

    this.changes = new Map([...this.changes, ...newChangeTypes]);
  }
  // for convenience, add a new method to add change of type 'maintanance'
  maintenance(change) {
    return this.addChange("maintenance", change);
  }
}

And once you want to use the parser:

const releaseCreator = (ver, date, desc) => new CustomRelease(ver, date, desc);
const 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:

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

Node:

npm install keep-a-changelog -g

Run the script:

changelog

To use other file name:

changelog --file=History.md

To generate an empty new CHANGELOG.md file:

changelog --init

You can release automatically the latest “Unreleased” version:

changelog --release

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

changelog --release 2.0.0

And return the latest released version:

changelog --latest-release
> 2.0.0

Available options:

Option Description
--format The output format for the generated markdown. It can be markdownlint or compact. The default value is compact.
--file The markdown file of the changelog. The default value is CHANGELOG.md.
--url The base url used to build the diff urls of the different releases. It is taken from the existing diff urls in the markdown. If no urls are found, try to catch it using the url of the git remote repository.
--https Set to false to use http instead https in the url (--https=false).
--init Init a new empty changelog file.
--latest-release Print the latest release version.
--release Updated the latest unreleased version with the current date. Use --release=X.Y.Z to set a number if the version doesn’t have it.
--create Create a new Unreleased version. Use --create=X.Y.Z to specify a version number or just --create for a version without number.
--quiet Do not output error messages
--head Customize the head reference