Uncaught TypeError: Cannot read property 'dispose' of undefined

[benogle]

From @MichaelReeder on December 10, 2014 14:43

Uncaught TypeError: Cannot read property 'dispose' of undefined

Atom Version: 0.154.0 System: Mac OS X 10.9.3 Thrown From: jsformat package

Steps To Reproduce

1. ...
2. ...

Stack Trace

At /Users/michaelreeder/.atom/packages/jsformat/lib/format.coffee:111

TypeError: Cannot read property 'dispose' of undefined
  at /Users/michaelreeder/.atom/packages/jsformat/lib/format.coffee:111:48
  at Emitter.module.exports.Emitter.emit (/Applications/Atom.app/Contents/Resources/app/node_modules/event-kit/lib/emitter.js:82:11)
  at TextBuffer.module.exports.TextBuffer.destroy (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:1049:22)
  at TextBuffer.module.exports.TextBuffer.release (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:1074:14)
  at TextEditor.module.exports.TextEditor.destroyed (/Applications/Atom.app/Contents/Resources/app/src/text-editor.js:260:19)
  at TextEditor.module.exports.Model.destroy (/Applications/Atom.app/Contents/Resources/app/node_modules/theorist/lib/model.js:218:14)
  at Pane.module.exports.Pane.destroyItem (/Applications/Atom.app/Contents/Resources/app/src/pane.js:445:18)
  at TabBarView.module.exports.TabBarView.closeTab (/Applications/Atom.app/Contents/Resources/app/node_modules/tabs/lib/tab-bar-view.js:267:24)
  at TabBarView.module.exports.TabBarView.closeAllTabs (/Applications/Atom.app/Contents/Resources/app/node_modules/tabs/lib/tab-bar-view.js:342:28)
  at space-pen-ul.subscriptions.add.atom.commands.add.tabs:close-all-tabs (/Applications/Atom.app/Contents/Resources/app/node_modules/tabs/lib/tab-bar-view.js:67:26)
  at CommandRegistry.module.exports.CommandRegistry.handleCommandEvent (/Applications/Atom.app/Contents/Resources/app/src/command-registry.js:243:29)
  at CommandRegistry.handleCommandEvent (/Applications/Atom.app/Contents/Resources/app/src/command-registry.js:3:61)
  at CommandRegistry.module.exports.CommandRegistry.dispatch (/Applications/Atom.app/Contents/Resources/app/src/command-registry.js:156:19)
  at [object Object].jQuery.fn.trigger (/Applications/Atom.app/Contents/Resources/app/src/space-pen-extensions.js:64:23)
  at Ipc.<anonymous> (/Applications/Atom.app/Contents/Resources/app/src/window-event-handler.js:70:67)
  at Ipc.emit (events.js:110:17)
  at process.<anonymous> (/Applications/Atom.app/Contents/Resources/atom/renderer/api/lib/ipc.js:22:29)
  at process.emit (events.js:118:17)
  at Ipc.sendSync (/Applications/Atom.app/Contents/Resources/atom/renderer/api/lib/ipc.js:39:29)
  at Ipc.sendChannelSync (/Applications/Atom.app/Contents/Resources/atom/renderer/api/lib/ipc.js:47:28)
  at BrowserWindow.RemoteMemberFunction [as emit] (/Applications/Atom.app/Contents/Resources/atom/renderer/api/lib/remote.js:110:29)
  at ContextMenuManager.module.exports.ContextMenuManager.showForEvent (/Applications/Atom.app/Contents/Resources/app/src/context-menu-manager.js:169:33)
  at HTMLDocument.<anonymous> (/Applications/Atom.app/Contents/Resources/app/src/window-event-handler.js:138:33)
  at HTMLDocument.handler (/Applications/Atom.app/Contents/Resources/app/src/space-pen-extensions.js:112:34)
  at HTMLDocument.jQuery.event.dispatch (/Applications/Atom.app/Contents/Resources/app/node_modules/space-pen/vendor/jquery.js:4681:9)
  at HTMLDocument.elemData.handle (/Applications/Atom.app/Contents/Resources/app/node_modules/space-pen/vendor/jquery.js:4359:46)

Copied from original issue: atom/atom#4504

[ilanbiala]

@benogle I've run into this error before, but I can't reproduce it. Debugging also shows that the particular line is almost never even called...I've found a lot of API inconsistencies and changes, is it possible that this snippet doesn't work anymore:

@editorCloseSubscriptions[editor.id] = buffer.onDidDestroy =>
        @editorSaveSubscriptions[editor.id].dispose()
        @editorCloseSubscriptions[editor.id].dispose()

        delete @editorSaveSubscriptions[editor.id]
        delete @editorCloseSubscriptions[editor.id]

[benogle]

A symptom fix could be to add ? before the dispose calls: @editorSaveSubscriptions[editor.id]?.dispose()

[ilanbiala]

But shouldn't it be set here. I'm not really sure it's set all the time, but that means the event callback isn't run if the code is correct.

@editorSaveSubscriptions[editor.id] = buffer.onWillSave =>
    if buffer.isModified()
      buffer.transact =>
        @format(state)

Suggestions?

[benogle]

I'm not totally following. You can use CompositeDisposables in that code though, rather than a save and a close hash, just one editorSubscriptions hash.

I think I see the problem. It's cause there can be multiple editors for each buffer. Is there a reason you're using buffers in that code rather than editors? Can you subscribe to the editors instead?

[ilanbiala]

Right, but if I need to dispose of one subscription, the composite won't do it. I was going to write a wrapper, but that just hides the hash in a class along with a composite..so I didn't think it would be very useful.

The textEditor API doesn't seem to provide an onWillSave event, unlike Buffer which does. It does have onDidDestroy though.

[ilanbiala]

Is there a way to subscribe to the onWillSave event for text editors? If so, then you can just point me to some docs and I think I'll be able to implement it pretty easily assuming it's the same API style.

[ilanbiala]

@benogle any answer to my previous comment?