cli: add global cache for binaries

[maxime1992]

Global cache will speed up local development when running npm i or yarn.
It'll downloaded Cypress binaries once and if available, next time will only get the cached one.

I believe it might also be safer for projects using Cypress to cache only that global cache folder + yarn or npm cache on CI instead of the whole node_modules.

This closes #1188

[CLAassistant]

All committers have signed the CLA.

[maxime1992]

So, I think it's good now, just waiting for comments 😄!

One thing tho: I don't know how to test the functionality for real (which is not ideal of course).

[brian-mann]

pinging @bahmutov

My thoughts:

There are some existing node modules that handle the "global cache" like this - which prevents you from having to build up the homeDir/.cypress/ pathing. We've had so many issues with Windows that we internally always look for modules that have already solved this in a cross platform way. Although this is minor - you shouldn't ever build up path slashes like you're doing because of Windows - always go through path.join(...)

Alternatively - Cypress itself uses the "proper" application cache of the OS which we utilize here https://github.com/cypress-io/cypress/blob/develop/packages/server/lib/util/app_data.coffee. It may make more sense to store the binaries there since we also give you a way to "View App Data" from the "File" menu from the GUI itself. It would make things more consistent and that code is already cross platform ready and would not create two different areas where we store data on your system. We'd need to extract this file into something more generic to make it available to the CLI.

As for testing this code for real - you generally just start from another project and call directly into the CLI code by invoking cypress/cli/bin/cypress directly. That should make it behave as if it's been NPM installed. You could also take an existing installation and just copy/paste your updated code into the NPM module.

[brian-mann]

@bahmutov thinking about this further....

Maybe instead of caching the zipped Cypress globally and then unzipping it into the dist folder within the NPM module -- why wouldn't we unzip it into the global cache and then just point the CLI to use the global version?

This would save you from having Cypress (which is very large) installed on multiple projects. As long as they use the same version number they'd all use the exact binary.

We'd have to likely come up with some new CLI flags to clear the cache when you want to do reinstall the binary or maybe a --force flag which bypasses the cache... but this seems to not only solve this issue of caching, but also fixes other issues people have asked for (that Cypress takes up too much space across multiple project installations).

[paulfalgout]

While I like where this is headed and it will help the issue, it won't resolve #1188 which seems to be that cloudflare is abysmal in the eastern hemisphere. Not only does re-downloading Cypress take 30 minutes, but the docs take an enormous amount of time to load.

[bahmutov]

I'm all for unzipping into same folder by cypress version. Also finding a module that can help if possible because cross platform is a nightmare. NPM cache location by default ``` Default: ~/.npm on Posix, or %AppData%/npm-cache on Windows. ``` From https://docs.npmjs.com/cli/cache though we have to be careful about storing anything in the NPM's cache. It can disappear or be blown away at any second. And guess what - NPM already caches package tgz file for us by version :) ``` $ l -R ~/.npm/cypress total 0 drwxr-xr-x 4 gleb staff 136 Jan 1 16:21 1.4.1 drwxr-xr-x 4 gleb staff 136 Feb 4 21:52 1.4.2 /Users/gleb/.npm/cypress/1.4.1: total 64 drwxr-xr-x 3 gleb staff 102 Feb 5 21:45 package -rw-r--r-- 1 gleb staff 30327 Jan 1 16:21 package.tgz /Users/gleb/.npm/cypress/1.4.1/package: total 8 -rw-r--r-- 1 gleb staff 2135 Feb 5 21:45 package.json /Users/gleb/.npm/cypress/1.4.2: total 80 drwxr-xr-x 3 gleb staff 102 Feb 5 21:33 package -rw-r--r-- 1 gleb staff 37472 Feb 4 21:52 package.tgz /Users/gleb/.npm/cypress/1.4.2/package: total 8 -rw-r--r-- 1 gleb staff 2134 Feb 5 21:33 package.json ``` Proposal: create another folder under NPM cache folder named `app`. Inside store unzipped Cypress in folders by version ``` ~/.npm/cypress /1.4.1 (package) /1.4.2 (package) /app /1.4.1 /Cypress.app info.json /1.4.2 /Cypress.app info.json ``` Maybe even as a first step add a flag to CLI to check and load Cypress app from a given folder?

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On Feb 6, 2018, at 23:53, Paul Falgout ***@***.***> wrote: While I like where this is headed and it will help the issue, it won't resolve #1188 which seems to be that cloudflare is abysmal in the eastern hemisphere. Not only does re-downloading Cypress take 30 minutes, but the docs take an enormous amount of time to load. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[bahmutov]

we should never concatenate paths ourselves (Windows ...)

[bahmutov]

BTW last comment: I usually do not struggle with Cypress installs because I use https://github.com/bahmutov/have-it to pull an alias from some other project that already has it installed

$ have -D cypress

[bahmutov]

@maxime1992 I will close this request in favor of #1300 - reusing same binary from different projects. This will avoid custom code and will do the same caching as other projects are doing (like Electron).