Why does yarn install checkout a github repository dependency but npm install does not?

Question

I'm listing a github repository (TypeScript project if it matters) as a dependency in package.json:

"ethereumjs-vm": "git+https://github.com/ethereumjs/ethereumjs-vm.git#v4.0.0-beta.1"

I want to extend some of the classes of this public project in my own project. With yarn install the whole repository gets checked out/copied (not a real git clone, since I can't run git commands) into node_modules/ethereumjsvm which is fine.

With npm install https://github.com/ethereumjs/ethereumjs-vm/tarball/v4.0.0-beta.1 --save the code gets checked out too.

With npm install I only get 4 files in node_modules/ethereumjsvm : changelog, license, package.json and readme.

What's the difference? Why does npm install does not get the source code from the repository?

Answer 1

Aaron Bell provided me with the answer: The files property in the package.json of the github project I want to include only contains the dist folder:

"files": [
   "dist/**/*"
]

This means npm install will ignore all other files in the repository (except changelog, license, package.json and readme which are always installed, see package.json files docs ). yarn seems to have a bug where this files property is ignored ( issue ).

After this I tried npm install with a project from github without a files property in package.json and it worked - the source code was stored in node_modules .