A very very simple demo and guide for explaining package manager.

As a JavaScript developer, you may use package manager like npm or Yarn frequently.

However, do you know how a package manager works? Or, you may be curious about how to build a package manager.

Well, the purpose of this guide is not to let you re-invent a new wheel. There is no need to do that because both npm and Yarn are mature and stable enough. The purpose is just to explain how a package manager works under the hood. You can read the code, and the comments will explain how it works.

Note: To simplify the guide and make it as simple as possible, this demo doesn't handle some edge cases and catch errors and exceptions. If you are really curious about that, it's recommended to read the source code of npm or Yarn.

• Download packages to node_modules directory.
• Simple CLI.
• Simply resolve dependency conflicts.
• Flatten dependencies tree.
• Support lock file. (Like yarn.lock or package-lock.json)
• Add a new package through CLI. (Like yarn add or npm i <package> command)
• Run lifecycle scripts. (preinstall and postinstall)
• Symlink the bin files.

Read the source code in the src directory. You can read the src/index.ts file in the beginning.

If you would like to try this simple package manager, just install it globally:

Via Yarn:

$ yarn global add tiny-package-manager

Via npm:

$ npm i -g tiny-package-manager

Then just go to a directory which contains valid package.json and run:

$ tiny-pm

MIT License (c) 2018-present Pig Fang