conditions.md
In dplyr: A Grammar of Data Manipulation

can pass verb-level error call

Code
  mutate(mtcars, 1 + "")
Condition
  Error in `foo()`:
  i In argument: `1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  transmute(mtcars, 1 + "")
Condition
  Error in `foo()`:
  i In argument: `1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  summarise(mtcars, 1 + "")
Condition
  Error in `foo()`:
  i In argument: `1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  summarise(group_by(mtcars, cyl), 1 + "")
Condition
  Error in `foo()`:
  i In argument: `1 + ""`.
  i In group 1: `cyl = 4`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  filter(mtcars, 1 + "")
Condition
  Error in `foo()`:
  i In argument: `1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  arrange(mtcars, 1 + "")
Condition
  Error in `foo()`:
  i In argument: `..1 = 1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  select(mtcars, 1 + "")
Condition
  Error in `foo()`:
  i In argument: `1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  slice(mtcars, 1 + "")
Condition
  Error in `foo()`:
  i In argument: `1 + ""`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator

can pass verb-level error call (example case)

Code
  my_verb(mtcars, 1 + "", am)
Condition
  Error in `my_verb()`:
  i In argument: `.result = (1 + "") * am`.
  Caused by error in `1 + ""`:
  ! non-numeric argument to binary operator
Code
  my_verb(mtcars, cyl, c(am, vs))
Condition
  Error in `my_verb()`:
  i In argument: `.result = cyl * c(am, vs)`.
  Caused by error:
  ! `.result` must be size 32 or 1, not 64.

`err_locs()` works as expected

Code
  err_locs(1.5)
Condition
  Error in `err_locs()`:
  ! `x` must be an integer vector of locations.
  i This is an internal error that was detected in the dplyr package.
    Please report it at <https://github.com/tidyverse/dplyr/issues> with a reprex (<https://tidyverse.org/help/>) and the full backtrace.

Code
  err_locs(integer())
Condition
  Error in `err_locs()`:
  ! `x` must have at least 1 location.
  i This is an internal error that was detected in the dplyr package.
    Please report it at <https://github.com/tidyverse/dplyr/issues> with a reprex (<https://tidyverse.org/help/>) and the full backtrace.

Code
  err_locs(1L)
Output
  `c(1)`
Code
  err_locs(1:5)
Output
  `c(1, 2, 3, 4, 5)`
Code
  err_locs(1:6)
Output
  `c(1, 2, 3, 4, 5)` and 1 more
Code
  err_locs(1:7)
Output
  `c(1, 2, 3, 4, 5)` and 2 more

errors during dots collection are not enriched (#6178)

Code
  mutate(mtcars, !!foobarbaz())
Condition
  Error in `foobarbaz()`:
  ! could not find function "foobarbaz"
Code
  transmute(mtcars, !!foobarbaz())
Condition
  Error in `foobarbaz()`:
  ! could not find function "foobarbaz"
Code
  select(mtcars, !!foobarbaz())
Condition
  Error in `foobarbaz()`:
  ! could not find function "foobarbaz"
Code
  arrange(mtcars, !!foobarbaz())
Condition
  Error in `foobarbaz()`:
  ! could not find function "foobarbaz"
Code
  filter(mtcars, !!foobarbaz())
Condition
  Error in `foobarbaz()`:
  ! could not find function "foobarbaz"

warnings are collected for `last_dplyr_warnings()`

Code
  # Ungrouped
  invisible(mutate(df, x = f()))
Condition
  Warning:
  There was 1 warning in `mutate()`.
  i In argument: `x = f()`.
  Caused by warning in `f()`:
  ! msg
Code
  last_dplyr_warnings()
Output
  [[1]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(df, x = f())
   2. \-dplyr:::mutate.data.frame(df, x = f())

Code
  # Grouped
  invisible(mutate(group_by(df, id), x = f()))
Condition
  Warning:
  There were 2 warnings in `mutate()`.
  The first warning was:
  i In argument: `x = f()`.
  i In group 1: `id = 1`.
  Caused by warning in `f()`:
  ! msg
  i Run `dplyr::last_dplyr_warnings()` to see the 1 remaining warning.
Code
  last_dplyr_warnings()
Output
  [[1]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In group 1: `id = 1`.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(group_by(df, id), x = f())
   2. \-dplyr:::mutate.data.frame(group_by(df, id), x = f())

  [[2]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In group 2: `id = 2`.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(group_by(df, id), x = f())
   2. \-dplyr:::mutate.data.frame(group_by(df, id), x = f())

Code
  # Rowwise
  invisible(mutate(rowwise(df), x = f()))
Condition
  Warning:
  There were 2 warnings in `mutate()`.
  The first warning was:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  i Run `dplyr::last_dplyr_warnings()` to see the 1 remaining warning.
Code
  last_dplyr_warnings()
Output
  [[1]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(rowwise(df), x = f())
   2. \-dplyr:::mutate.data.frame(rowwise(df), x = f())

  [[2]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In row 2.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(rowwise(df), x = f())
   2. \-dplyr:::mutate.data.frame(rowwise(df), x = f())

Code
  # Multiple type of warnings within multiple verbs
  invisible(mutate(group_by(mutate(rowwise(group_by(df, g = f():n())), x = f()),
  id), x = f()))
Condition
  Warning:
  There was 1 warning in `group_by()`.
  i In argument: `g = f():n()`.
  Caused by warning in `f()`:
  ! msg
  Warning:
  There were 2 warnings in `mutate()`.
  The first warning was:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  i Run `dplyr::last_dplyr_warnings()` to see the 1 remaining warning.
  Warning:
  There were 2 warnings in `mutate()`.
  The first warning was:
  i In argument: `x = f()`.
  i In group 1: `id = 1`.
  Caused by warning in `f()`:
  ! msg
  i Run `dplyr::last_dplyr_warnings()` to see the 1 remaining warning.
Code
  last_dplyr_warnings()
Output
  [[1]]
  <warning/rlang_warning>
  Warning in `group_by()`:
  i In argument: `g = f():n()`.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(...)
   2. +-dplyr::group_by(...)
   3. +-dplyr::mutate(rowwise(group_by(df, g = f():n())), x = f())
   4. +-dplyr::rowwise(group_by(df, g = f():n()))
   5. +-dplyr::group_by(df, g = f():n())
   6. \-dplyr:::group_by.data.frame(df, g = f():n())

  [[2]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(...)
   2. +-dplyr::group_by(...)
   3. +-dplyr::mutate(rowwise(group_by(df, g = f():n())), x = f())
   4. \-dplyr:::mutate.data.frame(...)

  [[3]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In row 2.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(...)
   2. +-dplyr::group_by(...)
   3. +-dplyr::mutate(rowwise(group_by(df, g = f():n())), x = f())
   4. \-dplyr:::mutate.data.frame(...)

  [[4]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In group 1: `id = 1`.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(...)
   2. \-dplyr:::mutate.data.frame(...)

  [[5]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In group 2: `id = 2`.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(...)
   2. \-dplyr:::mutate.data.frame(...)

Code
  # Truncated (1 more)
  mutate(rowwise(df), x = f())
Condition
  Warning:
  There were 2 warnings in `mutate()`.
  The first warning was:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  i Run `dplyr::last_dplyr_warnings()` to see the 1 remaining warning.
Output
  # A tibble: 2 x 2
  # Rowwise: 
       id     x
    <int> <dbl>
  1     1     1
  2     2     1
Code
  last_dplyr_warnings(n = 1)
Output
  [[1]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(rowwise(df), x = f())
   2. \-dplyr:::mutate.data.frame(rowwise(df), x = f())

Message
  ... with 1 more warning.
  i Run `dplyr::last_dplyr_warnings(n = 2)` to show more.

Code
  # Truncated (several more)
  df <- tibble(id = 1:5)
  mutate(rowwise(df), x = f())
Condition
  Warning:
  There were 5 warnings in `mutate()`.
  The first warning was:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  i Run `dplyr::last_dplyr_warnings()` to see the 4 remaining warnings.
Output
  # A tibble: 5 x 2
  # Rowwise: 
       id     x
    <int> <dbl>
  1     1     1
  2     2     1
  3     3     1
  4     4     1
  5     5     1
Code
  last_dplyr_warnings(n = 1)
Output
  [[1]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! msg
  ---
  Backtrace:
      x
   1. +-dplyr::mutate(rowwise(df), x = f())
   2. \-dplyr:::mutate.data.frame(rowwise(df), x = f())

Message
  ... with 4 more warnings.
  i Run `dplyr::last_dplyr_warnings(n = 2)` to show more.

complex backtraces with base and rlang warnings

Code
  foo()
Condition
  Warning:
  There was 1 warning in `group_by()`.
  i In argument: `x = f(1):n()`.
  Caused by warning in `h()`:
  ! foo
  Warning:
  There were 3 warnings in `mutate()`.
  The first warning was:
  i In argument: `x = f(1, base = FALSE)`.
  i In group 1: `x = 1`.
  Caused by warning:
  ! foo
  i Run `dplyr::last_dplyr_warnings()` to see the 2 remaining warnings.
Output
  # A tibble: 3 x 2
  # Groups:   x [1]
       id     x
    <int> <dbl>
  1     1     1
  2     2     1
  3     3     1
Code
  last_dplyr_warnings()
Output
  [[1]]
  <warning/rlang_warning>
  Warning in `group_by()`:
  i In argument: `x = f(1):n()`.
  Caused by warning in `h()`:
  ! foo
  ---
  Backtrace:
      x
   1. \-dplyr (local) foo()
   2.   \-dplyr (local) bar()
   3.     +-dplyr::mutate(group_by(df, x = f(1):n()), x = f(1, base = FALSE))
   4.     +-dplyr::group_by(df, x = f(1):n())
   5.     \-dplyr:::group_by.data.frame(df, x = f(1):n())

  [[2]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f(1, base = FALSE)`.
  i In group 1: `x = 1`.
  Caused by warning:
  ! foo
  ---
  Backtrace:
      x
   1. \-dplyr (local) foo()
   2.   \-dplyr (local) bar()
   3.     +-dplyr::mutate(group_by(df, x = f(1):n()), x = f(1, base = FALSE))
   4.     \-dplyr:::mutate.data.frame(...)

  [[3]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f(1, base = FALSE)`.
  i In group 2: `x = 2`.
  Caused by warning:
  ! foo
  ---
  Backtrace:
      x
   1. \-dplyr (local) foo()
   2.   \-dplyr (local) bar()
   3.     +-dplyr::mutate(group_by(df, x = f(1):n()), x = f(1, base = FALSE))
   4.     \-dplyr:::mutate.data.frame(...)

  [[4]]
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `x = f(1, base = FALSE)`.
  i In group 3: `x = 3`.
  Caused by warning:
  ! foo
  ---
  Backtrace:
      x
   1. \-dplyr (local) foo()
   2.   \-dplyr (local) bar()
   3.     +-dplyr::mutate(group_by(df, x = f(1):n()), x = f(1, base = FALSE))
   4.     \-dplyr:::mutate.data.frame(...)

can collect warnings in main verbs

Code
  invisible(summarise(mutate(arrange(filter(rowwise(mtcars), f()), f()), a = f()),
  b = f()))
Condition
  Warning:
  There were 32 warnings in `filter()`.
  The first warning was:
  i In argument: `f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! foo
  i Run `dplyr::last_dplyr_warnings()` to see the 31 remaining warnings.
  Warning:
  There was 1 warning in `arrange()`.
  i In argument: `..1 = f()`.
  Caused by warning in `f()`:
  ! foo
  Warning:
  There were 32 warnings in `mutate()`.
  The first warning was:
  i In argument: `a = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! foo
  i Run `dplyr::last_dplyr_warnings()` to see the 31 remaining warnings.
  Warning:
  There were 32 warnings in `summarise()`.
  The first warning was:
  i In argument: `b = f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! foo
  i Run `dplyr::last_dplyr_warnings()` to see the 31 remaining warnings.
Code
  warnings <- last_dplyr_warnings(Inf)
  warnings[[1]]
Output
  <warning/rlang_warning>
  Warning in `filter()`:
  i In argument: `f()`.
  i In row 1.
  Caused by warning in `f()`:
  ! foo
Code
  warnings[[33]]
Output
  <warning/rlang_warning>
  Warning in `arrange()`:
  i In argument: `..1 = f()`.
  Caused by warning in `f()`:
  ! foo
Code
  warnings[[65]]
Output
  <warning/rlang_warning>
  Warning in `mutate()`:
  i In argument: `a = f()`.
  i In row 32.
  Caused by warning in `f()`:
  ! foo
Code
  warnings[[97]]
Output
  <warning/rlang_warning>
  Warning in `summarise()`:
  i In argument: `b = f()`.
  i In row 32.
  Caused by warning in `f()`:
  ! foo