Use yarn for plugin installation

[karaggeorge]

Fixes #753

Uses yarn for plugin installation. Unfortunately yarn doesn't support prune, so I kept the npm binary as well.

I tested locally can didn't get any errors. There wasn't specific STR, it just happened sometimes, so I'll do some more testing to make sure the issue is resolved

[sindresorhus]

I could reliably reproduce this issue in master, but it works perfectly now with this PR.

[Codelica]

Just an FYI, as I was trying to debug issues with kap-nextcloud and my NextCloud server this morning and failing. :) This move to yarn will probably require an update to the docs here as npm link won't help.

For some reason yarn link wasn't working for me either though, not exactly sure why yet. I ran yarn link in my plugin directory, and can see the link via ls -al ~/.config/yarn/link/kap-nextcloud-dev, yet when Kap starts yarn errors. The following is in the yarn-error.log. It's as though the embedded yarn isn't respecting local system links.

Arguments:
  /Applications/Kap.app/Contents/MacOS/Kap /Applications/Kap.app/Contents/Resources/app.asar/node_modules/yarn/bin/yarn.js install --no-lockfile --registry https://registry.npmjs.org

PATH:
  /usr/bin:/bin:/usr/sbin:/sbin

Yarn version:
  1.19.1

Node version:
  12.4.0

Platform:
  darwin x64

Trace:
  Error: https://registry.npmjs.org/kap-nextcloud-dev: Not found
      at Request.params.callback [as _callback] (/Applications/Kap.app/Contents/Resources/app.asar/node_modules/yarn/lib/cli.js:66926:18)
      at Request.self.callback (/Applications/Kap.app/Contents/Resources/app.asar/node_modules/yarn/lib/cli.js:140564:22)
      at Request.emit (events.js:200:13)
      at Request.<anonymous> (/Applications/Kap.app/Contents/Resources/app.asar/node_modules/yarn/lib/cli.js:141536:10)
      at Request.emit (events.js:200:13)
      at IncomingMessage.<anonymous> (/Applications/Kap.app/Contents/Resources/app.asar/node_modules/yarn/lib/cli.js:141458:12)
      at Object.onceWrapper (events.js:288:20)
      at IncomingMessage.emit (events.js:205:15)
      at endReadableNT (_stream_readable.js:1154:12)
      at processTicksAndRejections (internal/process/task_queues.js:84:9)

npm manifest:
  {"dependencies":{"kap-nextcloud-dev":"latest","kap-gifski":"latest"}}

yarn manifest:
  No manifest

Lockfile:
  No lockfile

[karaggeorge]

@Codelica , when you run Kap built (prod mode) it runs npm prune and yarn install when it starts. If you want to test/develop plugins, my advice would be clone the kap repo, and run it in dev mode (yarn start). Then you should be able to follow the steps. I think npm link should still work, as long as you don't install/uninstall plugins from the UI while you are developing one locally.

[Codelica]

Ahh... thanks!

[karaggeorge]

@Codelica Thinking about it, there should be a workaround using the built app. If you open Kap, then run npm link and add the plugin to the package.json, after the app has started, you should be able to open the preferences and see it there (again as long as you don't install/uninstall a plugin)

[connor4312]

Should probably update the plugins.md doc. I was trying this tonight and running into the same error that Codelica pointed out.