# selection works with grouped data frames (#2624)

    Code
      out <- mutate_if(gdf, is.factor, as.character)
    Message
      `mutate_if()` ignored the following grouping variables:
      * Column `Species`

# colwise verbs deprecate quosures (#4330)

    Code
      (expect_warning(mutate_at(mtcars, vars(mpg), quo(mean(.)))))
    Output
      <warning/lifecycle_warning_deprecated>
      Warning:
      The `...` argument of `mutate_at()` can't contain quosures as of dplyr 0.8.3.
      i Please use a one-sided formula, a function, or a function name.
    Code
      (expect_warning(summarise_at(mtcars, vars(mpg), quo(mean(.)))))
    Output
      <warning/lifecycle_warning_deprecated>
      Warning:
      The `...` argument of `summarise_at()` can't contain quosures as of dplyr 0.8.3.
      i Please use a one-sided formula, a function, or a function name.

# colwise mutate gives meaningful error messages

    Code
      (expect_error(mutate_at(tibble(), "test", ~1)))
    Output
      <error/vctrs_error_subscript_oob>
      Error in `tbl_at_vars()`:
      ! Can't subset columns that don't exist.
      x Column `test` doesn't exist.
    Code
      tbl <- tibble(gr1 = rep(1:2, 4), gr2 = rep(1:2, each = 4), x = 1:8)
      tbl <- group_by(tbl, gr1)
      (expect_error(summarise_at(tbl, vars(gr1), mean)))
    Output
      <error/vctrs_error_subscript_oob>
      Error in `tbl_at_vars()`:
      ! Can't subset columns that don't exist.
      x Column `gr1` doesn't exist.
    Code
      (expect_error(mutate_all(mtcars, length, 0, 0)))
    Output
      <error/dplyr:::mutate_error>
      Error in `mutate()`:
      i In argument: `mpg = .Primitive("length")(mpg, 0, 0)`.
      Caused by error:
      ! 3 arguments passed to 'length' which requires 1
    Code
      (expect_error(mutate_all(mtcars, mean, na.rm = TRUE, na.rm = TRUE)))
    Output
      <error/dplyr:::mutate_error>
      Error in `mutate()`:
      i In argument: `mpg = (function (x, ...) ...`.
      Caused by error in `mean.default()`:
      ! formal argument "na.rm" matched by multiple actual arguments