case-match.md
In dplyr: A Grammar of Data Manipulation

requires at least one condition

Code
  case_match(1)
Condition
  Error in `case_match()`:
  ! At least one condition must be supplied.

Code
  case_match(1, NULL)
Condition
  Error in `case_match()`:
  ! At least one condition must be supplied.

`.default` is part of common type computation

Code
  case_match(1, 1 ~ 1L, .default = "x")
Condition
  Error in `case_match()`:
  ! Can't combine `..1 (right)` <integer> and `.default` <character>.

`NULL` formula element throws meaningful error

Code
  case_match(1, 1 ~ NULL)
Condition
  Error in `case_match()`:
  ! `..1 (right)` must be a vector, not `NULL`.

Code
  case_match(1, NULL ~ 1)
Condition
  Error in `case_match()`:
  ! `..1 (left)` must be a vector, not `NULL`.

throws chained errors when formula evaluation fails

Code
  case_match(1, 1 ~ 2, 3 ~ stop("oh no!"))
Condition
  Error in `case_match()`:
  ! Failed to evaluate the right-hand side of formula 2.
  Caused by error:
  ! oh no!

Code
  case_match(1, 1 ~ 2, stop("oh no!") ~ 4)
Condition
  Error in `case_match()`:
  ! Failed to evaluate the left-hand side of formula 2.
  Caused by error:
  ! oh no!