qdd

Example

npm i -g qdd
# And now, in a directory with a package-lock.json
qdd

Description

qdd is short for quickly download dependencies. That's all it does. It's meant as a replacement for npm ci in situations where:

• You don't need install scripts. (Note: this means no compiled modules.)
• You don't need the node_modules/.bin directory.

These two corners are cut in order to deliver modules to you at high speed. See the Benchmarks section below for more details.

This tool, qdd, is not meant as a replacement for npm or even for npm ci. npm is a full-featured JavaScript project management tool, and qdd is not. npm ci isn't a full-featured tool, but still is subject to some overhead in order to maintain levels of compatibility that we're completely ignoring.

All software is about tradeoffs. In this case, we're making the tradeoff that this tool is only useful if all your dependencies are install-script-free, and that you don't need the .bin directory. These are some pretty severe limitations, but in many situations, this is still good enough to get the job done.

Can I Use It?

To get an idea whether qdd might be appropriate for your project, check that the following are true:

• You don't rely on any dependencies' executables in your project's "scripts" in package.json.
• Your project operates just fine if you pass --ignore-scripts to npm or yarn when you install dependencies.
• Your operating system is UNIXey (*).

(*) Note: For the moment, Windows is not supported. This will change real soon, I swear!

Usage

In a directory containing a package-lock.json, run qdd on its own to install the dependencies into $PWD/node_modules/. The node_modules directory must not exist prior to running qdd. It will not be deleted automatically, as it would in npm ci.

To skip installing devDependencies, set the environment variable QDD_PROD to 1.

qdd will download dependencies with 10 sockets by default. You can change this number by setting the environment variable QDD_CONCURRENCY.

You can get some (very) verbose logging of what's happening inside qdd by setting the environment variable QDD_DEBUG to 1.

You can skip the usage of the cache directory entirely by setting the environment variable QDD_NOCACHE to 1.

Benchmarks

You can run the benchmarks with npm run bench. This will run both npm ci and qdd, both with primed caches and fresh caches, 10x for each case, and output the averages.

On my machine (a Lenovo X1 Carbon from mid 2016), this gives the following output:

 fresh cache npm ci (avg): 7.5899417363 seconds
    fresh cache qdd (avg): 3.9653772702 seconds
primed cache npm ci (avg): 5.4712137427 seconds
   primed cache qdd (avg): 0.4172178746 seconds

It's pretty quick, but remember that speed like this comes with tradeoffs.

Contributing

See CONTRIBUTING.md.

This project uses the Developer's Certificate of Origin. See DCO.txt.

Code of Conduct

See CODE_OF_CONDUCT.md.

License

MIT License. See LICENSE.txt.