seurat integration investigation

[sjspielman]

I'm reviving this comment for (optional, mostly for curiosity) discussion: #77 (comment)

...because I have now encountered the pseudo-error (since execution doesn't actually stop!) Error in x$.self$finalize() : attempt to apply non-function in a whole other context that might be useful for us to know. When doing some unit tests over in AlexsLemonade/scpcaTools#157, I encountered this error message when running expect_warning() and not saving the object within. In other words:

• expect_warning( run_thing() ) ---> error
• expect_warning( result <- run_thing() ) ---> no error

So, I'm going to say that Seurat is doing some kind of analogous operation internally, not capturing output that doesn't matter, and we are seeing the resulting error. Notably I have done 0 spelunking to back this theory up.

[jashapiro]

Curiousity: what happens when you do

expect_warning({
  result <- run_thing()
  result
})

or

expect_warning({
  result <- run_thing()
  result@slot
})