tests/testthat/_snaps/layer.md

In ggplot2: Create Elegant Data Visualisations Using the Grammar of Graphics

layer() checks its input

`geom` must be either a string or a <Geom> object, not `NULL`.

`stat` must be either a string or a <Stat> object, not `NULL`.

`position` must be either a string or a <Position> object, not `NULL`.

`mapping` must be created by `aes()`.
x You've supplied an integer vector.

`mapping` must be created by `aes()`.
x You've supplied a <ggplot2::ggplot> object.
i Did you use `%>%` or `|>` instead of `+`?

Can't find geom called "test".

`environment()` must be either a string or a <geom> object, not an environment.

Failed to retrieve a <Geom> object from `geom_foo()`.
Caused by error in `geom_foo()`:
! This function is unconstructable.

unknown params create warning

Ignoring unknown parameters: `blah`

unknown aesthetics create warning

Ignoring unknown aesthetics: blah

empty aesthetics create warning

Ignoring empty aesthetics: `fill` and `shape`.

invalid aesthetics throws errors

Problem while computing aesthetics.
i Error occurred in the 1st layer.
Caused by error:
! Aesthetics are not valid data columns.
x The following aesthetics are invalid:
* `fill = data`
i Did you mistype the name of a data column or forget to add `after_stat()`?

Problem while mapping stat to aesthetics.
i Error occurred in the 1st layer.
Caused by error:
! Aesthetics must be valid computed stats.
x The following aesthetics are invalid:
* `fill = after_stat(data)`
i Did you map your stat in the wrong layer?

missing aesthetics trigger informative error

Code
  ggplot_build(ggplot(df) + geom_line())
Condition
  Error in `geom_line()`:
  ! Problem while setting up geom.
  i Error occurred in the 1st layer.
  Caused by error in `compute_geom_1()`:
  ! `geom_line()` requires the following missing aesthetics: x and y.

Code
  ggplot_build(ggplot(df) + geom_col())
Condition
  Error in `geom_col()`:
  ! Problem while setting up geom.
  i Error occurred in the 1st layer.
  Caused by error in `compute_geom_1()`:
  ! `geom_col()` requires the following missing aesthetics: x and y.

function aesthetics are wrapped with after_stat()

Problem while computing aesthetics.
i Error occurred in the 1st layer.
Caused by error:
! Aesthetics are not valid data columns.
x The following aesthetics are invalid:
* `colour = density`
* `fill = density`
i Did you mistype the name of a data column or forget to add `after_stat()`?

computed stats are in appropriate layer

Problem while mapping stat to aesthetics.
i Error occurred in the 1st layer.
Caused by error:
! Aesthetics must be valid computed stats.
x The following aesthetics are invalid:
* `colour = after_stat(density)`
* `fill = after_stat(density)`
i Did you map your stat in the wrong layer?

layer reports the error with correct index etc

Problem while setting up geom.
i Error occurred in the 1st layer.
Caused by error in `compute_geom_1()`:
! `geom_linerange()` requires the following missing aesthetics: ymax or xmin and xmax.

Problem while converting geom to grob.
i Error occurred in the 2nd layer.
Caused by error in `draw_group()`:
! Can only draw one boxplot per group.
i Did you forget `aes(group = ...)`?

layer warns for constant aesthetics

All aesthetics have length 1, but the data has 32 rows.
i Please consider using `annotate()` or provide this layer with data containing a single row.

layer names can be resolved

Code
  p + l + l
Condition
  Error in `new_layer_names()`:
  ! Names must be unique.
  x These names are duplicated:
    * "foobar" at locations 3 and 4.

layer_data returns a data.frame

`layer_data()` must return a <data.frame>.

ggplot2 documentation built on Sept. 11, 2025, 9:10 a.m.