slow-deps to Measure NPM Install Time

The ability to quickly add dependencies to an npm project is a gift a curse -- the curse being you oftentimes have no control over those dependencies being available (i.e. the left-pad situation) and the have the potential to bloat your application or even increase project download time.  The truth is we should really be careful about what we depend on.

I recently found an awesome utility for measuring dependency download time and dependencies to dependencies:  slow-deps.  Start by installing slow-deps:

npm install -g slow-deps

After installed, navigate to the directory which hosts package.json and run slow-deps; the result will look something like this:

# Test Repo:  aframe

$ slow-deps
Analyzing 45 dependencies...
[====================] 100% 0.0s
---------------------------------------------------------------
| Dependency                    | Time     | Size    | # Deps |
---------------------------------------------------------------
| semistandard                  | 1m 14.4s | 24 MB   | 242    |
| tween.js                      | 1m 10.7s | 22 MB   | 250    |
| budo                          | 1m 1.4s  | 14 MB   | 275    |
| mozilla-download              | 49.3s    | 26 MB   | 194    |
| karma                         | 39.8s    | 16 MB   | 153    |
| snazzy                        | 36.2s    | 9.7 MB  | 146    |
| karma-coverage                | 26.7s    | 8.0 MB  | 99     |
| browserify                    | 23s      | 6.4 MB  | 118    |
| codecov                       | 17.8s    | 3.9 MB  | 73     |
| istanbul                      | 12.1s    | 6.5 MB  | 55     |
| minifyify                     | 11.4s    | 4.8 MB  | 48     |
| browserify-css                | 10.7s    | 4.0 MB  | 29     |
| document-register-element     | 9.7s     | 62 KB   | 0      |
| browserify-derequire          | 9.5s     | 1.7 MB  | 42     |
| mocha                         | 7.2s     | 1.3 MB  | 34     |
| gh-pages                      | 6.2s     | 3.7 MB  | 22     |
| three                         | 5.5s     | 10.0 MB | 0      |
| sinon                         | 5.3s     | 1.0 MB  | 5      |
| karma-browserify              | 5.2s     | 1.0 MB  | 9      |
| webvr-polyfill                | 4.2s     | 898 KB  | 2      |
| karma-mocha-reporter          | 4s       | 104 KB  | 7      |
| uglifyjs                      | 3.9s     | 752 KB  | 6      |
| rimraf                        | 3.6s     | 157 KB  | 11     |
| karma-sinon-chai              | 3.2s     | 146 KB  | 1      |
| replace                       | 3s       | 341 KB  | 7      |
| chai                          | 2.8s     | 438 KB  | 3      |
| karma-mocha                   | 2.8s     | 18 KB   | 0      |
| karma-chrome-launcher         | 2.6s     | 56 KB   | 5      |
| browserify-istanbul           | 2.5s     | 84 KB   | 5      |
| exorcist                      | 2.5s     | 143 KB  | 6      |
| lolex                         | 2.3s     | 122 KB  | 0      |
| karma-env-preprocessor        | 2.2s     | 5.8 KB  | 0      |
| mkdirp                        | 2s       | 47 KB   | 2      |
| chai-shallow-deep-equal       | 2s       | 17 KB   | 0      |
| husky                         | 2s       | 14 KB   | 1      |
| karma-firefox-launcher        | 1.9s     | 13 KB   | 0      |
| deep-assign                   | 1.9s     | 11 KB   | 1      |
| sinon-chai                    | 1.9s     | 18 KB   | 0      |
| debug                         | 1.5s     | 37 KB   | 1      |
| object-assign                 | 1.3s     | 7.4 KB  | 0      |
| open                          | 1.3s     | 26 KB   | 0      |
| karma-chai-shallow-deep-equal | 1.2s     | 6.8 KB  | 0      |
| present                       | 1.1s     | 12 KB   | 0      |
| promise-polyfill              | 1.1s     | 17 KB   | 0      |
| style-attr                    | 1s       | 6.5 KB  | 0      |
---------------------------------------------------------------
Total time (non-deduped): 9m 2s
Total size (non-deduped): 167 MB

You can see that there are a few dependencies which really slow down the install process due to a massive amount of its own dependencies.  Yikes!

So what can you do?  You can look for alternative packages which perform the same function but possible more dependencies.  If you aren't running npm install often (i.e. not deploying often), maybe this install time isn't a big deal; if you are, however, it's good to know the bottlenecks!