@jpfulton/node-license-auditor-cli

node-license-auditor-cli

A CLI designed to list and audit licenses in project dependencies in node projects. The CLI can output both markdown reports and CSV files and is designed to run in CI workflows. Included in the package is a DangerJS plugin that can be used to audit licenses in the PR process.

Installation of the CLI

You can install this tool globally, using the following yarn command:

yarn global add @jpfulton/node-license-auditor-cli

Local Configuration

To override the default configuration, which is extremely minimal, place a .license-checker.json file in the root directory of your project with the following format:

{
  "blackList": ["blacklisted-license"],
  "whiteList": ["whitelisted-license"]
}

Licenses in the blackList array will generate errors in the report. Licenses in the whiteList array will generate information lines and licenses types that exist in neither array generate warnings for further investigation.

License Identification Algorithm

The license identification algorithm uses a series of sources to identify the license type for each dependency. The algorithm uses the following sources in order:

1. The license field in the dependency's package.json file
2. The licenses field in the dependency's package.json file
3. A LICENSE file (or variation of that filename) in the dependency's root directory
4. A README file (or variation of that filename) in the dependency's root directory

Parsing of the package.json license and licenses fields respects the various formats in which those fields can be specified. For example, the license field can be specified as a string, an array of strings, or an object with a type field. Similarly, the licenses field can be specified as an array of strings or an array of objects with a type field. For more information on the license and licenses fields, see the package.json documentation.

If the license type cannot be identified using the above sources, the license type will be listed as UNKNOWN. The mechanism for identifying the license type is most accurate when the license or licenses field is present in the package.json file. Parsing of the LICENSE and README files is done using regular expressions and is not guaranteed to be as reliable as the package.json file.

For an understanding of the file name variations that are supported for LICENSE and README files, see the constants.ts file.

Licenses that cannot be identified

When a license for a dependency cannot be identified by the project, the license will be listed as UNKNOWN. It is useful to blacklist UNKNOWN licenses to ensure that all licenses are identified through a manual process. In some cases, UNKOWN licenses indicate that the project has no license and may be in the public domain. In other cases, UNKNOWN licenses indicate that the license simply could not be identified by the tool. In either case, it is useful to investigate the license and be selective about which dependencies are used in the project.

Remote Configurations

Remote configurations can be used to override the default configuration. To use a remote configuration, specify the URL to the configuration file using the --remote-config flag. Remote configurations are useful when applying the same configuration to multiple projects to avoid the need to copy the configuration file to each project and maintain the configurations in multiple places.

node-license-auditor-cli csv --remote-config https://raw.githubusercontent.com/jpfulton/node-license-auditor-cli/main/.license-checker.json . > report.csv

node-license-auditor-cli markdown --remote-config https://raw.githubusercontent.com/jpfulton/node-license-auditor-cli/main/.license-checker.json . > report.md

Usage as a DangerJS Plugin

This project can be used as a DangerJS plugin. To use the plugin, install the plugin using the following command:

yarn add -D danger @jpfulton/node-license-auditor-cli

Then, add the following to your dangerfile.ts:

import { licenseAuditor } from "@jpfulton/node-license-auditor-cli";

export default async () => {
  // Run the license auditor plugin
  await licenseAuditor({
    // optionally choose to fail the build if a blacklisted license is found
    failOnBlacklistedLicense: false,
    // specify the path to the project's package.json file, useful in a monorepo
    // defaults to the current working directory
    projectPath: ".",
    // optionally specify a remote configuration file
    // useful when applying the same configuration to multiple projects
    // defaults to usage of a local configuration file found at the root of the project repo
    remoteConfigurationUrl:
      "https://raw.githubusercontent.com/jpfulton/jpfulton-license-audits/main/.license-checker.json",
    // show a summary of the license audit in the PR comment
    // includes the number of unique dependencies and counts for each category of license found
    showMarkdownSummary: true,
    // show details of the license audit in the PR comment
    // includes a table with the name, version and license of each dependency
    // that was discovered that was not explicitly whitelisted in the configuration
    showMarkdownDetails: true,
  });
};