chop.md
In tidyr: Tidy Messy Data

chop() validates its input `cols` (#1205)

Code
  chop(df$x)
Condition
  Error in `chop()`:
  ! `data` must be a data frame, not an integer vector.
Code
  chop(df)
Condition
  Error in `chop()`:
  ! `cols` is absent but must be supplied.

incompatible sizes are caught

Code
  (expect_error(unchop(df, c(x, y))))
Output
  <error/rlang_error>
  Error in `unchop()`:
  ! In row 1, can't recycle input of size 2 to size 3.

empty typed inputs are considered in common size, but NULLs aren't

Code
  (expect_error(unchop(df, c(x, y))))
Output
  <error/rlang_error>
  Error in `unchop()`:
  ! In row 1, can't recycle input of size 0 to size 2.

unchop disallows renaming

Code
  unchop(df, c(y = x))
Condition
  Error in `unchop()`:
  ! Can't rename variables in this context.

unchop validates its inputs

Code
  unchop(1:10)
Condition
  Error in `unchop()`:
  ! `data` must be a data frame, not an integer vector.
Code
  unchop(df)
Condition
  Error in `unchop()`:
  ! `cols` is absent but must be supplied.
Code
  unchop(df, col, keep_empty = 1)
Condition
  Error in `unchop()`:
  ! `keep_empty` must be `TRUE` or `FALSE`, not the number 1.
Code
  unchop(df, col, ptype = 1)
Condition
  Error in `unchop()`:
  ! `ptype` must be `NULL`, an empty ptype, or a named list of ptypes.