Show error in PackageDetailView when network is unavailable and package is not in cache

[izuzak]

This fixes #634. It seems that AtomIoClient.fetchFromCache calls the callback with a special combination of values in case the network is unavailable and the package was not found in cache. This special value was handled elsewhere, but needed to be handled in PackageDetailView as well.

068ce24 adds a failing spec, which triggers this error:

PackageDetailView
  it shows an error when package metadata cannot be loaded from the cache and the network is unavailable
    TypeError: Cannot read property 'on' of undefined
      at PackageCard.module.exports.PackageCard.handleButtonEvents (/Users/izuzak/github/settings-view/lib/package-card.coffee:157:17)
      at PackageCard.module.exports.PackageCard.initialize (/Users/izuzak/github/settings-view/lib/package-card.coffee:69:6)
      at PackageCard.View (/Users/izuzak/github/settings-view/node_modules/atom-space-pen-views/node_modules/space-pen/lib/space-pen.js:184:25)
      at new PackageCard (/Users/izuzak/github/settings-view/lib/package-card.coffee:11:3)
      at PackageDetailView.module.exports.PackageDetailView.completeInitialzation (/Users/izuzak/github/settings-view/lib/package-detail-view.coffee:63:26)
      at /Users/izuzak/github/settings-view/lib/package-detail-view.coffee:98:10
      at /Users/izuzak/github/settings-view/lib/atom-io-client.coffee:32:9
      at AtomIoClient.<anonymous> (/Users/izuzak/github/settings-view/spec/package-detail-view-spec.coffee:69:7)
      at AtomIoClient.module.exports.AtomIoClient.package (/Users/izuzak/github/settings-view/lib/atom-io-client.coffee:30:6)
      at PackageDetailView.module.exports.PackageDetailView.fetchPackage (/Users/izuzak/github/settings-view/lib/package-detail-view.coffee:89:5)
      at PackageDetailView.module.exports.PackageDetailView.loadPackage (/Users/izuzak/github/settings-view/lib/package-detail-view.coffee:83:10)
      at PackageDetailView.module.exports.PackageDetailView.initialize (/Users/izuzak/github/settings-view/lib/package-detail-view.coffee:59:6)
      at PackageDetailView.View (/Users/izuzak/github/settings-view/node_modules/atom-space-pen-views/node_modules/space-pen/lib/space-pen.js:184:25)
      at new PackageDetailView (/Users/izuzak/github/settings-view/lib/package-detail-view.coffee:22:3)
      at [object Object].<anonymous> (/Users/izuzak/github/settings-view/spec/package-detail-view-spec.coffee:71:16)

d8cc61f fixes the problem by checking the data returned by AtomIoClient and verifying that it has at least the package's name property before showing the package card.

cc @kevinsawicki and @thedaniel for 👀

[thedaniel]

AtomIoClient.fetchFromCache calls the callback with a special combination of values in case the network is unavailable and the package was not found in cache.

CLASSIC @thedaniel! Anyway, this seems fine for a quick fix, but if we're going to show an error, maybe we should just pass in an error instead of an imaginary value, and things will work in a more predictable way. Of course, that requires updating the other callers that special case {}

[izuzak]

Anyway, this seems fine for a quick fix, but if we're going to show an error, maybe we should just pass in an error instead of an imaginary value, and things will work in a more predictable way. Of course, that requires updating the other callers that special case {}

Yep, definitely agree with you. I'm intentionally going for a quick fix until I get a better understanding of this package's crazy complexity (I'm fixing small issues here and there for now). I'll open a new issue so that we don't forget to refactor this. 👍