eval-select.md
In tidyselect: Select from a Set of Strings

include and exclude validate their inputs

Code
  x <- list(a = 1, b = 2, c = 3)
  (expect_error(select_loc(x, "a", include = 1)))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  ! `include` must be a character vector.
Code
  (expect_error(select_loc(x, "a", include = "d")))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  ! `include` must only include variables found in `data`.
  i Unknown variables: d
Code
  (expect_error(select_loc(x, "a", exclude = 1)))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  ! `include` must be a character vector.

can forbid rename syntax (#178)

Code
  (expect_error(select_loc(mtcars, c(foo = cyl), allow_rename = FALSE)))
Output
  <error/tidyselect:::error_disallowed_rename>
  Error in `select_loc()`:
  ! Can't rename variables in this context.
Code
  (expect_error(select_loc(mtcars, c(cyl, foo = cyl), allow_rename = FALSE)))
Output
  <error/tidyselect:::error_disallowed_rename>
  Error in `select_loc()`:
  ! Can't rename variables in this context.
Code
  (expect_error(select_loc(mtcars, c(cyl, foo = mpg), allow_rename = FALSE)))
Output
  <error/tidyselect:::error_disallowed_rename>
  Error in `select_loc()`:
  ! Can't rename variables in this context.
Code
  (expect_error(select_loc(mtcars, c(foo = mpg, cyl), allow_rename = FALSE)))
Output
  <error/tidyselect:::error_disallowed_rename>
  Error in `select_loc()`:
  ! Can't rename variables in this context.

can forbid empty selections

Code
  select_loc(mtcars, allow_empty = FALSE)
Condition
  Error in `select_loc()`:
  ! Must select at least one item.
Code
  select_loc(mtcars, integer(), allow_empty = FALSE)
Condition
  Error in `select_loc()`:
  ! Must select at least one item.
Code
  select_loc(mtcars, starts_with("z"), allow_empty = FALSE)
Condition
  Error in `select_loc()`:
  ! Must select at least one item.

eval_select() errors mention correct calls

Code
  (expect_error(select_loc(mtcars, f())))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  Caused by error in `f()`:
  ! foo

predicate outputs are type-checked

Code
  (expect_error(select_loc(mtcars, function(x) "")))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  ! Predicate must return `TRUE` or `FALSE`, not `""`.

eval_select() produces correct backtraces

Code
  print(expect_error(select_loc(mtcars, f(base = TRUE))))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  i In argument: `f(base = TRUE)`.
  Caused by error in `h()`:
  ! foo
  ---
  Backtrace:
       x
    1. +-base::print(expect_error(select_loc(mtcars, f(base = TRUE))))
    2. +-testthat::expect_error(select_loc(mtcars, f(base = TRUE)))
    3. | \-testthat:::expect_condition_matching(...)
    4. |   \-testthat:::quasi_capture(...)
    5. |     +-testthat (local) .capture(...)
    6. |     | \-base::withCallingHandlers(...)
    7. |     \-rlang::eval_bare(quo_get_expr(.quo), quo_get_env(.quo))
    8. +-tidyselect:::select_loc(mtcars, f(base = TRUE))
    9. | \-tidyselect::eval_select(...)
   10. |   \-tidyselect:::eval_select_impl(...)
   11. |     +-tidyselect:::with_subscript_errors(...)
   12. |     | \-base::withCallingHandlers(...)
   13. |     \-tidyselect:::vars_select_eval(...)
   14. |       \-tidyselect:::walk_data_tree(expr, data_mask, context_mask)
   15. |         \-tidyselect:::eval_context(expr, context_mask, call = error_call)
   16. |           +-tidyselect:::with_chained_errors(...)
   17. |           | \-base::withCallingHandlers(...)
   18. |           \-rlang::eval_tidy(as_quosure(expr, env), context_mask)
   19. \-tidyselect (local) f(base = TRUE)
   20.   \-tidyselect (local) g(base)
   21.     \-tidyselect (local) h(base)
   22.       \-base::stop("foo")
Code
  print(expect_error(select_loc(mtcars, f(base = FALSE))))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  i In argument: `f(base = FALSE)`.
  Caused by error in `h()`:
  ! foo
  ---
  Backtrace:
       x
    1. +-base::print(expect_error(select_loc(mtcars, f(base = FALSE))))
    2. +-testthat::expect_error(select_loc(mtcars, f(base = FALSE)))
    3. | \-testthat:::expect_condition_matching(...)
    4. |   \-testthat:::quasi_capture(...)
    5. |     +-testthat (local) .capture(...)
    6. |     | \-base::withCallingHandlers(...)
    7. |     \-rlang::eval_bare(quo_get_expr(.quo), quo_get_env(.quo))
    8. +-tidyselect:::select_loc(mtcars, f(base = FALSE))
    9. | \-tidyselect::eval_select(...)
   10. |   \-tidyselect:::eval_select_impl(...)
   11. |     +-tidyselect:::with_subscript_errors(...)
   12. |     | \-base::withCallingHandlers(...)
   13. |     \-tidyselect:::vars_select_eval(...)
   14. |       \-tidyselect:::walk_data_tree(expr, data_mask, context_mask)
   15. |         \-tidyselect:::eval_context(expr, context_mask, call = error_call)
   16. |           +-tidyselect:::with_chained_errors(...)
   17. |           | \-base::withCallingHandlers(...)
   18. |           \-rlang::eval_tidy(as_quosure(expr, env), context_mask)
   19. \-tidyselect (local) f(base = FALSE)
   20.   \-tidyselect (local) g(base)
   21.     \-tidyselect (local) h(base)

eval_select() produces correct chained errors

Code
  (expect_error(select_loc(mtcars, 1 + "")))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  i In argument: `1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  f <- (function() 1 + "")
  (expect_error(select_loc(mtcars, f())))
Output
  <error/rlang_error>
  Error in `select_loc()`:
  i In argument: `f()`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator