@rushstack/package-deps-hash

What is @rushstack/package-deps-hash?

@rushstack/package-deps-hash is a utility for computing a hash based on the contents of a package and its dependencies. This is particularly useful for build systems and caching mechanisms where you need to determine if a package or its dependencies have changed.

What are @rushstack/package-deps-hash's main functionalities?

Compute Package Hash

This feature allows you to compute a hash for a given package directory. The hash is based on the contents of the package and its dependencies, which can be used to determine if any changes have occurred.

const { getPackageDeps } = require('@rushstack/package-deps-hash');
const path = require('path');

async function computeHash() {
  const packagePath = path.resolve(__dirname, 'path/to/your/package');
  const packageDeps = await getPackageDeps(packagePath);
  console.log(packageDeps);
}

computeHash();

Custom File Globs

This feature allows you to specify custom file globs to include in the hash computation. This can be useful if you want to include or exclude specific files or types of files in the hash calculation.

const { getPackageDeps } = require('@rushstack/package-deps-hash');
const path = require('path');

async function computeHashWithGlobs() {
  const packagePath = path.resolve(__dirname, 'path/to/your/package');
  const customGlobs = ['**/*.js', '**/*.json'];
  const packageDeps = await getPackageDeps(packagePath, { globs: customGlobs });
  console.log(packageDeps);
}

computeHashWithGlobs();

Other packages similar to @rushstack/package-deps-hash

hasha

hasha is a package for hashing files and strings using various algorithms. It is more general-purpose compared to @rushstack/package-deps-hash, which is specifically designed for hashing package dependencies.

crypto

crypto is a built-in Node.js module that provides cryptographic functionality, including hashing. While it can be used to hash files and strings, it does not provide the same level of convenience for hashing package dependencies as @rushstack/package-deps-hash.

webpack

webpack is a module bundler that includes functionality for hashing the contents of bundles. While it can be used to achieve similar goals, it is a much larger and more complex tool compared to @rushstack/package-deps-hash.

README

@rushstack/package-deps-hash

The package-deps-hash library generates a JSON object containing the git hashes of all files used to produce a given package. This is useful for scenarios where you want to define a "change receipt" file to be published with a package. The Rush tool uses this library to implement incremental build detection.

Only files in a git repo that are not in .gitignore will be considered in building the hash. The file content and the current state of the package can be compared then to determine whether the package needs to be rebuilt.

Internally it uses the GIT hashes to derive the hashes for package content. This allows the process to leverage Git's hash optimizations, as opposed to creating a more elaborate diffing scheme.

NOTE: Git is required to be accessible in the command line path.

Usage

let _ = require('lodash');
let { getPackageDeps } = require('@rushstack/package-deps-hash');

// Gets the current deps object for the current working directory
let deps = getPackageDeps();
let existingDeps = JSON.parse(fs.readFileSync('package-deps.json'));

if (_.isEqual(deps, existingDeps)) {
  // Skip re-building package.
} else {
  // Rebuild package.
}

Links

• CHANGELOG.md - Find out what's new in the latest version
• API Reference

@rushstack/package-deps-hash is part of the Rush Stack family of projects.