stub depth > 1 not working for R6 classes

[adamborondy]

I am trying to use mockery::stub() in combination with an R6 class, which works out fine for functions at a depth of 1. Here is a simplified R6 example:

library(mockery)

stubTest <- R6::R6Class(classname = "stubTest",
  public =
    list(
      sum = 0,
      add_x = function() {
        self$sum <- self$sum + self$add_y()
        invisible(self)
      },
      add_y = function() {
        self$add_z()
      },
      add_z = function() {
        5
      }
    )
)

I can successfully stub self$add_y like this:

test_that('Stubbing test depth 1', {
  st <- stubTest$new()
  stub(st$add_x, 'self$add_y', 10, depth = 1)
  st$add_x()
  expect_equal(st$sum, 10)
})

However I cannot do the same for self$add_z at a depth of 2. This results in an actual value of 5 as expected without stubbing:

test_that('Stubbing test depth 2', {
  st <- stubTest$new()
  stub(st$add_x, 'self$add_z', 10, depth = 2)
  st$add_x()
  expect_equal(st$sum, 10)
})

I'm not sure if this feature is applicable to R6 classes in this way, so I appreciate any feedback!

[hadley]

mockery is no longer under active development as we now recommend using testthat::local_mocked_bindings() instead. That doesn't yet support mocking R6 methods, but we could certainly consider it if it's a popular need.

[hadley]

I've filed an issue to look into this for testthat: r-lib/testthat#1892