Dims in str for data.frame-inheriting object

[jonthegeek]

This line is causing me issues:

S7/R/class.R

Line 305 in f5b23ab

attributes(object) <- list(names = names(object), dim = dim(object))

I have a subclass of data.frame, "paths". This is the hackiest part of my package and likely to change, but the tests work before and now throw an error, so I want to report this while I see it.

When my test tries to print an object that contains a "rapid::paths" object (and thus calls str()), I get an error. You can reproduce it like this:

library(S7)
df <- data.frame(a = 1:2, b = 1:2)
# Imagine that df belongs to an S7 subclass of data.frame.
class(df) <- c("myclass", "data.frame", "S7_object")
str(df)
#> Classes 'myclass', 'S7_object' and 'data.frame': 2 obs. of  2 variables:
#> <myclass>
#> Error in attributes(object) <- list(names = names(object), dim = dim(object)): dims [product 4] do not match the length of object [2]

^{Created on 2024-11-12 with reprex v2.1.1}

Or more directly like this:

x <- data.frame(a = 1:2, b = 1:2)
attributes(x) <- list(dim = dim(x))

I suspect I can avoid this by implementing a str method like I've been meaning to do anyway (not to mention that this object likely won't inherit from data.frame much longer), but it also seems like this is probably a bug.