objects with reference semantics can break containment of qenv

[chlebowa]

Objects that have reference semantics (e.g. environments, R6 objects, data.table), when created in the global environment and packaged into teal_data, allow for modifying the contents of teal_data from without.

library(teal.data)
library(data.table)

d1 <- as.data.table(iris)
td <- teal_data(d1 = d1, code = quote(d1 <- as.data.table(iris)))
within(td, print(head(d1)))
get_code(td) |> cat()

d1[, species := as.integer(Species)]
within(td, print(head(d1)))

This is a potential breach in code reproducibility.

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Note that once code is evaluated within teal_data, the result is a deep copy because @env is cloned under the hood.

tdd <- within(td, d1 <- head(d1))
within(tdd, print(d1))
within(td, print(d1))