Bug/issue 661 unmounting bug

[narinluangrath]

Description

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.

Another one liner fix. We use setInterval to pan through the slides automatically (if the user sets the autoplay and autoplayOnStart props). We just forgot to run clearInterval if the component unmounts. Consequently, _nextSlide keeps getting run even when the Deck is unmounted, leading to some weird behavior if Deck gets mounted again.

Fixes #661

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

You can reproduce the problem here: #661
To prove the fix worked I did the following:

• cd into spectacle-bug-demo
• change the package.json to "spectacle": "FormidableLabs/spectacle#bug/issue-661-unmounting-bug"
• cd into node_modules/spectacle
• yarn install && yarn build
• startup the demo and the bug is fixed

I also added a test to Manager.js

[kale-stew]

🚢

[glassblowerscat]

🙌