nest-tree.md
In tibblify: Rectangle Nested Lists

checks arguments

Code
  (expect_error(nest_tree(1L)))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! `data` must be a data frame.
Code
  (expect_error(nest_tree(df, "not-there")))
Output
  <error/vctrs_error_subscript_oob>
  Error in `eval_pull()`:
  ! Can't subset columns that don't exist.
  x Column `not-there` doesn't exist.
Code
  (expect_error(nest_tree(df, 1:2)))
Output
  <error/rlang_error>
  Error in `eval_pull()`:
  ! `id_col` must select 1 column, not 2.
Code
  (expect_error(nest_tree(df, id, parent_col = "not-there")))
Output
  <error/vctrs_error_subscript_oob>
  Error in `eval_pull()`:
  ! Can't subset columns that don't exist.
  x Column `not-there` doesn't exist.
Code
  (expect_error(nest_tree(df, id, parent_col = 1:2)))
Output
  <error/rlang_error>
  Error in `eval_pull()`:
  ! `parent_col` must select 1 column, not 2.
Code
  (expect_error(nest_tree(df, id, parent_col = id)))
Output
  <error/rlang_error>
  Error in `check_parent_col()`:
  ! `parent_col` must be different from `id_col`.
Code
  (expect_error(nest_tree(df, id, parent, children_to = 1L)))
Output
  <error/vctrs_error_cast>
  Error in `nest_tree()`:
  ! Can't convert `children_to` <integer> to <character>.
Code
  (expect_error(nest_tree(df, id, parent, children_to = c("a", "b"))))
Output
  <error/vctrs_error_assert_size>
  Error in `nest_tree()`:
  ! `children_to` must have size 1, not size 2.
Code
  (expect_error(nest_tree(df, id, parent, children_to = "id")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! `children_to` must be different from `id_col`.
Code
  (expect_error(nest_tree(df, id, parent, children_to = "parent")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! `children_to` must be different from `parent_col`.

checks that ids are valid

Code
  (expect_error(nest_tree(df, id, parent, children_to = "children")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! Each value of column id must be non-missing.
  i Element 2 is missing.

Code
  (expect_error(nest_tree(df, id, parent, children_to = "children")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! Each value of column id must be unique.
  i The elements at locations 1 and 2 are duplicated.

checks column ids and parents have compatible types

Code
  (expect_error(nest_tree(df, id, parent, children_to = "children")))
Output
  <error/vctrs_error_cast>
  Error in `check_parent_col()`:
  ! Can't convert `data$parent` <character> to match type of `data$id` <integer>.

errors if not all parent ids found

Code
  (expect_error(nest_tree(df, id, parent, children_to = "children")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! The parent of each element must be found.
  i The parent ids 4 and 5 are not found.
Code
  (expect_error(nest_tree(df[1:2, ], id, parent, children_to = "children")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! The parent of each element must be found.
  i The parent id 4 is not found.

errors if parent references to itself

Code
  (expect_error(nest_tree(df, id, parent, children_to = "children")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! An element must not be its own parent
  i Element 2 refers to itself as parent.

errors if there are no root elements

Code
  (expect_error(nest_tree(df, id, parent, children_to = "children")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! There must be root elements.
  i A root element is an elements whose parent id is missing.

errors if there are detached parts of the tree

Code
  (expect_error(nest_tree(df, id, parent, children_to = "children")))
Output
  <error/rlang_error>
  Error in `nest_tree()`:
  ! Each element must be connected to a root element.
  i The elements 2 and 3 are not connected.