From 7321e4705ac83f7e86f6a86991ebe1fe2ae164ed Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 23 May 2022 10:13:02 +0200
Subject: [PATCH 1/8] Update ggproto to call methods by name instead of through
 f()

---
 R/ggproto.r | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/R/ggproto.r b/R/ggproto.r
index 04cd0a0198..4607ae03d9 100644
--- a/R/ggproto.r
+++ b/R/ggproto.r
@@ -153,7 +153,7 @@ fetch_ggproto <- function(x, name) {
     return(res)
   }
 
-  make_proto_method(x, res)
+  make_proto_method(x, res, name)
 }
 
 #' @export
@@ -163,19 +163,22 @@ fetch_ggproto <- function(x, name) {
     return(res)
   }
 
-  make_proto_method(.subset2(x, "self"), res)
+  make_proto_method(.subset2(x, "self"), res, name)
 }
 
-make_proto_method <- function(self, f) {
+make_proto_method <- function(self, f, name) {
   args <- formals(f)
   # is.null is a fast path for a common case; the %in% check is slower but also
   # catches the case where there's a `self = NULL` argument.
   has_self  <- !is.null(args[["self"]]) || "self"  %in% names(args)
 
+  # We assign the method with its correct name and construct a call to it to
+  # make errors reported as coming from the method name rather than `f()`
+  assign(name, f, envir = environment())
   if (has_self) {
-    fun <- function(...) f(..., self = self)
+    fun <- inject(function(...) !!call2(name, quote(...), self = quote(self)))
   } else {
-    fun <- function(...) f(...)
+    fun <- inject(function(...) !!call2(name, quote(...)))
   }
 
   class(fun) <- "ggproto_method"

From 8e3ff5a124bc8a7713ead3f7aeead7ab6ce2491f Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 23 May 2022 10:13:28 +0200
Subject: [PATCH 2/8] Fix error wording

---
 R/layer.r | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/R/layer.r b/R/layer.r
index 5cdf9d241c..f4db11d6fe 100644
--- a/R/layer.r
+++ b/R/layer.r
@@ -328,7 +328,7 @@ Layer <- ggproto("Layer", NULL,
       issues <- paste0("{.code ", nondata_stat_cols, " = ", as_label(aesthetics[[nondata_stat_cols]]), "}")
       names(issues) <- rep("x", length(issues))
       cli::cli_abort(c(
-        "Aesthetics are not valid computed stats.",
+        "Aesthetics must be valid computed stats.",
         "x" = "The following aesthetics are invalid:",
         issues,
         "i" = "Did you map your stat in the wrong layer?"

From bad27209c4b07b3e8fe2a6274b890a7f17b00267 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 23 May 2022 10:16:21 +0200
Subject: [PATCH 3/8] Store the layer constructor in the layer

---
 R/layer-sf.R | 6 +++++-
 R/layer.r    | 4 ++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/R/layer-sf.R b/R/layer-sf.R
index c583fba16d..3fcf8fd2cd 100644
--- a/R/layer-sf.R
+++ b/R/layer-sf.R
@@ -13,6 +13,7 @@ layer_sf <- function(geom = NULL, stat = NULL,
                      position = NULL, params = list(),
                      inherit.aes = TRUE, check.aes = TRUE, check.param = TRUE,
                      show.legend = NA) {
+  call_env <- caller_env()
   if (is.character(show.legend)) {
     legend_key_type <- show.legend
     show.legend <- TRUE
@@ -21,7 +22,10 @@ layer_sf <- function(geom = NULL, stat = NULL,
   }
 
   # inherit from LayerSf class to add `legend_key_type` slot
-  layer_class <- ggproto(NULL, LayerSf, legend_key_type = legend_key_type)
+  layer_class <- ggproto(NULL, LayerSf,
+    constructor = frame_call(call_env),
+    legend_key_type = legend_key_type
+  )
 
   layer(
     geom = geom, stat = stat, data = data, mapping = mapping,
diff --git a/R/layer.r b/R/layer.r
index f4db11d6fe..b065a2c10d 100644
--- a/R/layer.r
+++ b/R/layer.r
@@ -140,7 +140,10 @@ layer <- function(geom = NULL, stat = NULL,
   # adjust the legend draw key if requested
   geom <- set_draw_key(geom, key_glyph)
 
+  fr_call <- layer_class$constructor %||% frame_call(call_env)
+
   ggproto("LayerInstance", layer_class,
+    constructor = fr_call,
     geom = geom,
     geom_params = geom_params,
     stat = stat,
@@ -169,6 +172,7 @@ validate_mapping <- function(mapping, call = caller_env()) {
 }
 
 Layer <- ggproto("Layer", NULL,
+  constructor = NULL,
   geom = NULL,
   geom_params = NULL,
   stat = NULL,

From 887ec8d9e851c551dd663525784d400871b4eef8 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 23 May 2022 10:17:13 +0200
Subject: [PATCH 4/8] modify by_layer to use try_fetch and throw contextual
 errors

---
 R/plot-build.r | 43 +++++++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/R/plot-build.r b/R/plot-build.r
index e1c8b8acc6..ca2920331c 100644
--- a/R/plot-build.r
+++ b/R/plot-build.r
@@ -35,19 +35,11 @@ ggplot_build.ggplot <- function(plot) {
   data <- rep(list(NULL), length(layers))
 
   scales <- plot$scales
-  # Apply function to layer and matching data
-  by_layer <- function(f) {
-    out <- vector("list", length(data))
-    for (i in seq_along(data)) {
-      out[[i]] <- f(l = layers[[i]], d = data[[i]])
-    }
-    out
-  }
 
   # Allow all layers to make any final adjustments based
   # on raw input data and plot info
-  data <- by_layer(function(l, d) l$layer_data(plot$data))
-  data <- by_layer(function(l, d) l$setup_layer(d, plot))
+  data <- by_layer(function(l, d) l$layer_data(plot$data), layers, data, "computing layer data")
+  data <- by_layer(function(l, d) l$setup_layer(d, plot), layers, data, "setting up layer")
 
   # Initialise panels, add extra data for margins & missing faceting
   # variables, and add on a PANEL variable to data
@@ -55,7 +47,7 @@ ggplot_build.ggplot <- function(plot) {
   data <- layout$setup(data, plot$data, plot$plot_env)
 
   # Compute aesthetics to produce data with generalised variable names
-  data <- by_layer(function(l, d) l$compute_aesthetics(d, plot))
+  data <- by_layer(function(l, d) l$compute_aesthetics(d, plot), layers, data, "computing aesthetics")
 
   # Transform all scales
   data <- lapply(data, scales_transform_df, scales = scales)
@@ -69,17 +61,17 @@ ggplot_build.ggplot <- function(plot) {
   data <- layout$map_position(data)
 
   # Apply and map statistics
-  data <- by_layer(function(l, d) l$compute_statistic(d, layout))
-  data <- by_layer(function(l, d) l$map_statistic(d, plot))
+  data <- by_layer(function(l, d) l$compute_statistic(d, layout), layers, data, "computing statistics")
+  data <- by_layer(function(l, d) l$map_statistic(d, plot), layers, data, "mapping statistics to aesthetics")
 
   # Make sure missing (but required) aesthetics are added
   scales_add_missing(plot, c("x", "y"), plot$plot_env)
 
   # Reparameterise geoms from (e.g.) y and width to ymin and ymax
-  data <- by_layer(function(l, d) l$compute_geom_1(d))
+  data <- by_layer(function(l, d) l$compute_geom_1(d), layers, data, "setting up geom")
 
   # Apply position adjustments
-  data <- by_layer(function(l, d) l$compute_position(d, layout))
+  data <- by_layer(function(l, d) l$compute_position(d, layout), layers, data, "computing positions")
 
   # Reset position scales, then re-train and map.  This ensures that facets
   # have control over the range of a plot: is it generated from what is
@@ -97,10 +89,10 @@ ggplot_build.ggplot <- function(plot) {
   }
 
   # Fill in defaults etc.
-  data <- by_layer(function(l, d) l$compute_geom_2(d))
+  data <- by_layer(function(l, d) l$compute_geom_2(d), layers, data, "setting up geom aesthetics")
 
   # Let layer stat have a final say before rendering
-  data <- by_layer(function(l, d) l$finish_statistics(d))
+  data <- by_layer(function(l, d) l$finish_statistics(d), layers, data, "finishing layer stat")
 
   # Let Layout modify data before rendering
   data <- layout$finish_data(data)
@@ -168,7 +160,7 @@ ggplot_gtable.ggplot_built <- function(data) {
   data <- data$data
   theme <- plot_theme(plot)
 
-  geom_grobs <- Map(function(l, d) l$draw_geom(d, layout), plot$layers, data)
+  geom_grobs <- by_layer(function(l, d) l$draw_geom(d, layout), plot$layers, data, "converting geom to grob")
   layout$setup_panel_guides(plot$guides, plot$layers, plot$mapping)
   plot_table <- layout$render(geom_grobs, data, theme, plot$labels)
 
@@ -419,3 +411,18 @@ ggplot_gtable.ggplot_built <- function(data) {
 ggplotGrob <- function(x) {
   ggplot_gtable(ggplot_build(x))
 }
+
+# Apply function to layer and matching data
+by_layer <- function(f, layers, data, step = NULL) {
+  ordinal <- label_ordinal()
+  out <- vector("list", length(data))
+  try_fetch(
+    for (i in seq_along(data)) {
+      out[[i]] <- f(l = layers[[i]], d = data[[i]])
+    },
+    error = function(cnd) {
+      cli::cli_abort(c("Problem {step}", "i" = "Error occurred in the {ordinal(i)} layer"), call = I(layers[[i]]$constructor), parent = cnd)
+    }
+  )
+  out
+}

From ee392abed288e0a89f11803dab5b037488cfc2d9 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 23 May 2022 10:17:27 +0200
Subject: [PATCH 5/8] update test snapshots

---
 tests/testthat/_snaps/annotate.md             | 10 ++++++++--
 tests/testthat/_snaps/geom-.md                |  5 ++++-
 tests/testthat/_snaps/geom-dotplot.md         |  4 ++--
 tests/testthat/_snaps/geom-linerange.md       |  5 ++++-
 tests/testthat/_snaps/geom-path.md            |  5 ++++-
 tests/testthat/_snaps/geom-raster.md          |  5 ++++-
 tests/testthat/_snaps/geom-ribbon.md          | 15 +++++++++++---
 tests/testthat/_snaps/geom-sf.md              |  5 ++++-
 tests/testthat/_snaps/geom-violin.md          | 10 ++++++++--
 tests/testthat/_snaps/guides.md               | 20 +++++++++----------
 tests/testthat/_snaps/layer.md                | 20 +++++++++++++++----
 tests/testthat/_snaps/position-jitterdodge.md |  5 ++++-
 tests/testthat/_snaps/stat-bin.md             | 20 +++++++++++++++----
 tests/testthat/_snaps/stat-boxplot.md         |  5 ++++-
 tests/testthat/_snaps/stat-count.md           | 10 ++++++++--
 tests/testthat/_snaps/stat-density.md         |  5 ++++-
 tests/testthat/_snaps/stat-density2d.md       |  5 ++++-
 tests/testthat/_snaps/stat-ecdf.md            |  5 ++++-
 tests/testthat/_snaps/stat-qq.md              |  6 +++---
 19 files changed, 123 insertions(+), 42 deletions(-)

diff --git a/tests/testthat/_snaps/annotate.md b/tests/testthat/_snaps/annotate.md
index 02c670d6a6..49bdbae686 100644
--- a/tests/testthat/_snaps/annotate.md
+++ b/tests/testthat/_snaps/annotate.md
@@ -1,10 +1,16 @@
 # annotation_raster() and annotation_custom() requires cartesian coordinates
 
-    `annotation_raster()` only works with `coord_cartesian()`
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_panel()`:
+    ! `annotation_raster()` only works with `coord_cartesian()`
 
 ---
 
-    `annotation_custom()` only works with `coord_cartesian()`
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_panel()`:
+    ! `annotation_custom()` only works with `coord_cartesian()`
 
 # annotation_map() checks the input data
 
diff --git a/tests/testthat/_snaps/geom-.md b/tests/testthat/_snaps/geom-.md
index 08c938f136..5b1a09893b 100644
--- a/tests/testthat/_snaps/geom-.md
+++ b/tests/testthat/_snaps/geom-.md
@@ -1,6 +1,9 @@
 # aesthetic checking in geom throws correct errors
 
-    Aesthetic modifiers returned invalid values
+    Problem setting up geom aesthetics
+    i Error occurred in the 1st layer
+    Caused by error in `use_defaults()`:
+    ! Aesthetic modifiers returned invalid values
     x The following mappings are invalid
     x `colour = after_scale(data)`
     i Did you map the modifier in the wrong layer?
diff --git a/tests/testthat/_snaps/geom-dotplot.md b/tests/testthat/_snaps/geom-dotplot.md
index 020e4dc948..b2e9f5b5ac 100644
--- a/tests/testthat/_snaps/geom-dotplot.md
+++ b/tests/testthat/_snaps/geom-dotplot.md
@@ -5,12 +5,12 @@
 # weight aesthetic is checked
 
     Computation failed in `stat_bindot()`
-    Caused by error in `f()`:
+    Caused by error in `compute_group()`:
     ! Weights must be nonnegative integers.
 
 ---
 
     Computation failed in `stat_bindot()`
-    Caused by error in `f()`:
+    Caused by error in `compute_group()`:
     ! Weights must be nonnegative integers.
 
diff --git a/tests/testthat/_snaps/geom-linerange.md b/tests/testthat/_snaps/geom-linerange.md
index 0ed2d2f407..c4aba72fee 100644
--- a/tests/testthat/_snaps/geom-linerange.md
+++ b/tests/testthat/_snaps/geom-linerange.md
@@ -1,4 +1,7 @@
 # geom_linerange request the right aesthetics
 
-    `geom_linerange()` requires the following missing aesthetics: ymax or xmin and xmax
+    Problem 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
 
diff --git a/tests/testthat/_snaps/geom-path.md b/tests/testthat/_snaps/geom-path.md
index c649779131..8faf36169e 100644
--- a/tests/testthat/_snaps/geom-path.md
+++ b/tests/testthat/_snaps/geom-path.md
@@ -1,4 +1,7 @@
 # geom_path() throws meaningful error on bad combination of varying aesthetics
 
-    `geom_path()` can't have varying colour, size, and/or alpha along the line when linetype isn't solid
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_panel()`:
+    ! `geom_path()` can't have varying colour, size, and/or alpha along the line when linetype isn't solid
 
diff --git a/tests/testthat/_snaps/geom-raster.md b/tests/testthat/_snaps/geom-raster.md
index 342f4a3c4c..472621c042 100644
--- a/tests/testthat/_snaps/geom-raster.md
+++ b/tests/testthat/_snaps/geom-raster.md
@@ -16,5 +16,8 @@
 
 ---
 
-    `geom_raster()` only works with `coord_cartesian()`
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_panel()`:
+    ! `geom_raster()` only works with `coord_cartesian()`
 
diff --git a/tests/testthat/_snaps/geom-ribbon.md b/tests/testthat/_snaps/geom-ribbon.md
index a76f72a577..0521405dae 100644
--- a/tests/testthat/_snaps/geom-ribbon.md
+++ b/tests/testthat/_snaps/geom-ribbon.md
@@ -1,14 +1,23 @@
 # geom_ribbon() checks the aesthetics
 
-    Either xmin or xmax must be given as an aesthetic.
+    Problem setting up geom
+    i Error occurred in the 1st layer
+    Caused by error in `setup_data()`:
+    ! Either xmin or xmax must be given as an aesthetic.
 
 ---
 
-    Either ymin or ymax must be given as an aesthetic.
+    Problem setting up geom
+    i Error occurred in the 1st layer
+    Caused by error in `setup_data()`:
+    ! Either ymin or ymax must be given as an aesthetic.
 
 ---
 
-    Aesthetics can not vary along a ribbon
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_group()`:
+    ! Aesthetics can not vary along a ribbon
 
 ---
 
diff --git a/tests/testthat/_snaps/geom-sf.md b/tests/testthat/_snaps/geom-sf.md
index 180b0b277b..b9c09fda3d 100644
--- a/tests/testthat/_snaps/geom-sf.md
+++ b/tests/testthat/_snaps/geom-sf.md
@@ -1,6 +1,9 @@
 # errors are correctly triggered
 
-    `geom_sf()` can only be used with `coord_sf()`
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_panel()`:
+    ! `geom_sf()` can only be used with `coord_sf()`
 
 ---
 
diff --git a/tests/testthat/_snaps/geom-violin.md b/tests/testthat/_snaps/geom-violin.md
index acf43a4654..e3608a86c2 100644
--- a/tests/testthat/_snaps/geom-violin.md
+++ b/tests/testthat/_snaps/geom-violin.md
@@ -1,8 +1,14 @@
 # quantiles fails outside 0-1 bound
 
-    `draw_quantiles` must be between 0 and 1
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_group()`:
+    ! `draw_quantiles` must be between 0 and 1
 
 ---
 
-    `draw_quantiles` must be between 0 and 1
+    Problem converting geom to grob
+    i Error occurred in the 1st layer
+    Caused by error in `draw_group()`:
+    ! `draw_quantiles` must be between 0 and 1
 
diff --git a/tests/testthat/_snaps/guides.md b/tests/testthat/_snaps/guides.md
index 4b9f4b317b..88a8a97b71 100644
--- a/tests/testthat/_snaps/guides.md
+++ b/tests/testthat/_snaps/guides.md
@@ -1,13 +1,3 @@
-# binning scales understand the different combinations of limits, breaks, labels, and show.limits
-
-    `show.limits` is ignored when `labels` are given as a character vector
-    i Either add the limits to `breaks` or provide a function for `labels`
-
----
-
-    `show.limits` is ignored when `labels` are given as a character vector
-    i Either add the limits to `breaks` or provide a function for `labels`
-
 # axis_label_element_overrides errors when angles are outside the range [0, 90]
 
     Unrecognized `axis_position`: "test"
@@ -68,6 +58,16 @@
     Breaks not formatted correctly for a bin legend.
     i Use `(<lower>, <upper>]` format to indicate bins
 
+# binning scales understand the different combinations of limits, breaks, labels, and show.limits
+
+    `show.limits` is ignored when `labels` are given as a character vector
+    i Either add the limits to `breaks` or provide a function for `labels`
+
+---
+
+    `show.limits` is ignored when `labels` are given as a character vector
+    i Either add the limits to `breaks` or provide a function for `labels`
+
 # a warning is generated when guides(<scale> = FALSE) is specified
 
     `guide = FALSE` is deprecated
diff --git a/tests/testthat/_snaps/layer.md b/tests/testthat/_snaps/layer.md
index 76b269cf88..a3c62a08dd 100644
--- a/tests/testthat/_snaps/layer.md
+++ b/tests/testthat/_snaps/layer.md
@@ -29,21 +29,30 @@
 
 # invalid aesthetics throws errors
 
-    Aesthetics are not valid data columns.
+    Problem computing aesthetics
+    i Error occurred in the 1st layer
+    Caused by error in `compute_aesthetics()`:
+    ! Aesthetics are not valid data columns.
     x The following aesthetics are invalid:
     x `fill = data`
     i Did you mistype the name of a data column or forget to add `after_stat()`?
 
 ---
 
-    Aesthetics are not valid computed stats.
+    Problem mapping statistics to aesthetics
+    i Error occurred in the 1st layer
+    Caused by error in `map_statistic()`:
+    ! Aesthetics must be valid computed stats.
     x The following aesthetics are invalid:
     x `fill = after_stat(data)`
     i Did you map your stat in the wrong layer?
 
 # function aesthetics are wrapped with stat()
 
-    Aesthetics are not valid data columns.
+    Problem computing aesthetics
+    i Error occurred in the 1st layer
+    Caused by error in `compute_aesthetics()`:
+    ! Aesthetics are not valid data columns.
     x The following aesthetics are invalid:
     x `colour = NULL`
     x `fill = NULL`
@@ -51,7 +60,10 @@
 
 # computed stats are in appropriate layer
 
-    Aesthetics are not valid computed stats.
+    Problem mapping statistics to aesthetics
+    i Error occurred in the 1st layer
+    Caused by error in `map_statistic()`:
+    ! Aesthetics must be valid computed stats.
     x The following aesthetics are invalid:
     x `colour = NULL`
     x `fill = NULL`
diff --git a/tests/testthat/_snaps/position-jitterdodge.md b/tests/testthat/_snaps/position-jitterdodge.md
index ca5337eedc..485d8bbf02 100644
--- a/tests/testthat/_snaps/position-jitterdodge.md
+++ b/tests/testthat/_snaps/position-jitterdodge.md
@@ -1,4 +1,7 @@
 # position_jitterdodge() fails with meaningful error
 
-    `position_jitterdodge()` requires at least one aesthetic to dodge by
+    Problem computing positions
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `position_jitterdodge()` requires at least one aesthetic to dodge by
 
diff --git a/tests/testthat/_snaps/stat-bin.md b/tests/testthat/_snaps/stat-bin.md
index 9bcf6dad64..aabdc610f2 100644
--- a/tests/testthat/_snaps/stat-bin.md
+++ b/tests/testthat/_snaps/stat-bin.md
@@ -1,14 +1,23 @@
 # stat_bin throws error when wrong combination of aesthetic is present
 
-    `stat_bin()` requires an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_bin()` requires an x or y aesthetic.
 
 ---
 
-    `stat_bin()` must only have an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_bin()` must only have an x or y aesthetic.
 
 ---
 
-    `stat_bin()` requires a continuous x aesthetic
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_bin()` requires a continuous x aesthetic
     x the x aesthetic is discrete.
     i Perhaps you want `stat="count"`?
 
@@ -46,5 +55,8 @@
 
 # stat_count throws error when both x and y aesthetic present
 
-    `stat_count()` must only have an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_count()` must only have an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-boxplot.md b/tests/testthat/_snaps/stat-boxplot.md
index 1f95358b33..2e930ca60b 100644
--- a/tests/testthat/_snaps/stat-boxplot.md
+++ b/tests/testthat/_snaps/stat-boxplot.md
@@ -8,5 +8,8 @@
 
 # stat_boxplot errors with missing x/y aesthetics
 
-    `stat_boxplot()` requires an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_boxplot()` requires an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-count.md b/tests/testthat/_snaps/stat-count.md
index 2229ecc762..fb62f3233b 100644
--- a/tests/testthat/_snaps/stat-count.md
+++ b/tests/testthat/_snaps/stat-count.md
@@ -1,8 +1,14 @@
 # stat_count() checks the aesthetics
 
-    `stat_count()` requires an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_count()` requires an x or y aesthetic.
 
 ---
 
-    `stat_count()` must only have an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_count()` must only have an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-density.md b/tests/testthat/_snaps/stat-density.md
index 31e70ca675..66dce9699a 100644
--- a/tests/testthat/_snaps/stat-density.md
+++ b/tests/testthat/_snaps/stat-density.md
@@ -1,4 +1,7 @@
 # stat_density works in both directions
 
-    `stat_density()` requires an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_density()` requires an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-density2d.md b/tests/testthat/_snaps/stat-density2d.md
index 54a9c30575..0aafb0754b 100644
--- a/tests/testthat/_snaps/stat-density2d.md
+++ b/tests/testthat/_snaps/stat-density2d.md
@@ -1,5 +1,8 @@
 # stat_density2d can produce contour and raster data
 
-    Invalid value of `contour_var` ("abcd")
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `compute_layer()`:
+    ! Invalid value of `contour_var` ("abcd")
     i Supported values are "density", "ndensity", and "count".
 
diff --git a/tests/testthat/_snaps/stat-ecdf.md b/tests/testthat/_snaps/stat-ecdf.md
index ef492fab44..74b2187ce3 100644
--- a/tests/testthat/_snaps/stat-ecdf.md
+++ b/tests/testthat/_snaps/stat-ecdf.md
@@ -1,4 +1,7 @@
 # stat_ecdf works in both directions
 
-    `stat_ecdf()` requires an x or y aesthetic.
+    Problem computing statistics
+    i Error occurred in the 1st layer
+    Caused by error in `setup_params()`:
+    ! `stat_ecdf()` requires an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-qq.md b/tests/testthat/_snaps/stat-qq.md
index 0c22addb7c..24f4890db7 100644
--- a/tests/testthat/_snaps/stat-qq.md
+++ b/tests/testthat/_snaps/stat-qq.md
@@ -1,18 +1,18 @@
 # error is thrown with wrong quantile input
 
     Computation failed in `stat_qq()`
-    Caused by error in `f()`:
+    Caused by error in `compute_group()`:
     ! The length of `quantiles` must match the length of the data
 
 ---
 
     Computation failed in `stat_qq_line()`
-    Caused by error in `f()`:
+    Caused by error in `compute_group()`:
     ! `quantiles` must have the same length as the data
 
 ---
 
     Computation failed in `stat_qq_line()`
-    Caused by error in `f()`:
+    Caused by error in `compute_group()`:
     ! Cannot fit line quantiles 0.15. `line.p` must have length 2.
 

From 50d999f38caa58d0d0a62339c4b97a2d6714eeea Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 23 May 2022 10:34:07 +0200
Subject: [PATCH 6/8] improve method construction in ggproto

---
 R/ggproto.r | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/R/ggproto.r b/R/ggproto.r
index 4607ae03d9..d6b0533f01 100644
--- a/R/ggproto.r
+++ b/R/ggproto.r
@@ -175,11 +175,11 @@ make_proto_method <- function(self, f, name) {
   # We assign the method with its correct name and construct a call to it to
   # make errors reported as coming from the method name rather than `f()`
   assign(name, f, envir = environment())
+  args <- list(quote(...))
   if (has_self) {
-    fun <- inject(function(...) !!call2(name, quote(...), self = quote(self)))
-  } else {
-    fun <- inject(function(...) !!call2(name, quote(...)))
+    args$self <- quote(self)
   }
+  fun <- inject(function(...) !!call2(name, !!!args))
 
   class(fun) <- "ggproto_method"
   fun

From 9c3eb9cdb5129709ca8140e63f39a3f2732664fc Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Tue, 24 May 2022 14:08:35 +0200
Subject: [PATCH 7/8] imrpove message based on comments

---
 R/plot-build.r | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/R/plot-build.r b/R/plot-build.r
index ca2920331c..c5fc0a566c 100644
--- a/R/plot-build.r
+++ b/R/plot-build.r
@@ -61,8 +61,8 @@ ggplot_build.ggplot <- function(plot) {
   data <- layout$map_position(data)
 
   # Apply and map statistics
-  data <- by_layer(function(l, d) l$compute_statistic(d, layout), layers, data, "computing statistics")
-  data <- by_layer(function(l, d) l$map_statistic(d, plot), layers, data, "mapping statistics to aesthetics")
+  data <- by_layer(function(l, d) l$compute_statistic(d, layout), layers, data, "computing stat")
+  data <- by_layer(function(l, d) l$map_statistic(d, plot), layers, data, "mapping stat to aesthetics")
 
   # Make sure missing (but required) aesthetics are added
   scales_add_missing(plot, c("x", "y"), plot$plot_env)
@@ -71,7 +71,7 @@ ggplot_build.ggplot <- function(plot) {
   data <- by_layer(function(l, d) l$compute_geom_1(d), layers, data, "setting up geom")
 
   # Apply position adjustments
-  data <- by_layer(function(l, d) l$compute_position(d, layout), layers, data, "computing positions")
+  data <- by_layer(function(l, d) l$compute_position(d, layout), layers, data, "computing position")
 
   # Reset position scales, then re-train and map.  This ensures that facets
   # have control over the range of a plot: is it generated from what is
@@ -421,7 +421,7 @@ by_layer <- function(f, layers, data, step = NULL) {
       out[[i]] <- f(l = layers[[i]], d = data[[i]])
     },
     error = function(cnd) {
-      cli::cli_abort(c("Problem {step}", "i" = "Error occurred in the {ordinal(i)} layer"), call = I(layers[[i]]$constructor), parent = cnd)
+      cli::cli_abort(c("Problem while {step}.", "i" = "Error occurred in the {ordinal(i)} layer."), call = I(layers[[i]]$constructor), parent = cnd)
     }
   )
   out

From 5091d15f3e394e732b4e3c8b51f72e62fa3b94d5 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Tue, 24 May 2022 14:15:32 +0200
Subject: [PATCH 8/8] update error snapshots

---
 tests/testthat/_snaps/annotate.md             |  8 ++++----
 tests/testthat/_snaps/geom-.md                |  4 ++--
 tests/testthat/_snaps/geom-linerange.md       |  4 ++--
 tests/testthat/_snaps/geom-path.md            |  4 ++--
 tests/testthat/_snaps/geom-raster.md          |  4 ++--
 tests/testthat/_snaps/geom-ribbon.md          | 12 ++++++------
 tests/testthat/_snaps/geom-sf.md              |  4 ++--
 tests/testthat/_snaps/geom-violin.md          |  8 ++++----
 tests/testthat/_snaps/layer.md                | 16 ++++++++--------
 tests/testthat/_snaps/position-jitterdodge.md |  4 ++--
 tests/testthat/_snaps/stat-bin.md             | 16 ++++++++--------
 tests/testthat/_snaps/stat-boxplot.md         |  4 ++--
 tests/testthat/_snaps/stat-count.md           |  8 ++++----
 tests/testthat/_snaps/stat-density.md         |  4 ++--
 tests/testthat/_snaps/stat-density2d.md       |  4 ++--
 tests/testthat/_snaps/stat-ecdf.md            |  4 ++--
 16 files changed, 54 insertions(+), 54 deletions(-)

diff --git a/tests/testthat/_snaps/annotate.md b/tests/testthat/_snaps/annotate.md
index 49bdbae686..ed67a8d029 100644
--- a/tests/testthat/_snaps/annotate.md
+++ b/tests/testthat/_snaps/annotate.md
@@ -1,14 +1,14 @@
 # annotation_raster() and annotation_custom() requires cartesian coordinates
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_panel()`:
     ! `annotation_raster()` only works with `coord_cartesian()`
 
 ---
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_panel()`:
     ! `annotation_custom()` only works with `coord_cartesian()`
 
diff --git a/tests/testthat/_snaps/geom-.md b/tests/testthat/_snaps/geom-.md
index 5b1a09893b..46be5c85c3 100644
--- a/tests/testthat/_snaps/geom-.md
+++ b/tests/testthat/_snaps/geom-.md
@@ -1,7 +1,7 @@
 # aesthetic checking in geom throws correct errors
 
-    Problem setting up geom aesthetics
-    i Error occurred in the 1st layer
+    Problem while setting up geom aesthetics.
+    i Error occurred in the 1st layer.
     Caused by error in `use_defaults()`:
     ! Aesthetic modifiers returned invalid values
     x The following mappings are invalid
diff --git a/tests/testthat/_snaps/geom-linerange.md b/tests/testthat/_snaps/geom-linerange.md
index c4aba72fee..840ed7d604 100644
--- a/tests/testthat/_snaps/geom-linerange.md
+++ b/tests/testthat/_snaps/geom-linerange.md
@@ -1,7 +1,7 @@
 # geom_linerange request the right aesthetics
 
-    Problem setting up geom
-    i Error occurred in the 1st layer
+    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
 
diff --git a/tests/testthat/_snaps/geom-path.md b/tests/testthat/_snaps/geom-path.md
index 8faf36169e..af6d86df60 100644
--- a/tests/testthat/_snaps/geom-path.md
+++ b/tests/testthat/_snaps/geom-path.md
@@ -1,7 +1,7 @@
 # geom_path() throws meaningful error on bad combination of varying aesthetics
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_panel()`:
     ! `geom_path()` can't have varying colour, size, and/or alpha along the line when linetype isn't solid
 
diff --git a/tests/testthat/_snaps/geom-raster.md b/tests/testthat/_snaps/geom-raster.md
index 472621c042..37115972d2 100644
--- a/tests/testthat/_snaps/geom-raster.md
+++ b/tests/testthat/_snaps/geom-raster.md
@@ -16,8 +16,8 @@
 
 ---
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_panel()`:
     ! `geom_raster()` only works with `coord_cartesian()`
 
diff --git a/tests/testthat/_snaps/geom-ribbon.md b/tests/testthat/_snaps/geom-ribbon.md
index 0521405dae..af4c34752f 100644
--- a/tests/testthat/_snaps/geom-ribbon.md
+++ b/tests/testthat/_snaps/geom-ribbon.md
@@ -1,21 +1,21 @@
 # geom_ribbon() checks the aesthetics
 
-    Problem setting up geom
-    i Error occurred in the 1st layer
+    Problem while setting up geom.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_data()`:
     ! Either xmin or xmax must be given as an aesthetic.
 
 ---
 
-    Problem setting up geom
-    i Error occurred in the 1st layer
+    Problem while setting up geom.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_data()`:
     ! Either ymin or ymax must be given as an aesthetic.
 
 ---
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_group()`:
     ! Aesthetics can not vary along a ribbon
 
diff --git a/tests/testthat/_snaps/geom-sf.md b/tests/testthat/_snaps/geom-sf.md
index b9c09fda3d..b65a327f8a 100644
--- a/tests/testthat/_snaps/geom-sf.md
+++ b/tests/testthat/_snaps/geom-sf.md
@@ -1,7 +1,7 @@
 # errors are correctly triggered
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_panel()`:
     ! `geom_sf()` can only be used with `coord_sf()`
 
diff --git a/tests/testthat/_snaps/geom-violin.md b/tests/testthat/_snaps/geom-violin.md
index e3608a86c2..fff4046b0d 100644
--- a/tests/testthat/_snaps/geom-violin.md
+++ b/tests/testthat/_snaps/geom-violin.md
@@ -1,14 +1,14 @@
 # quantiles fails outside 0-1 bound
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_group()`:
     ! `draw_quantiles` must be between 0 and 1
 
 ---
 
-    Problem converting geom to grob
-    i Error occurred in the 1st layer
+    Problem while converting geom to grob.
+    i Error occurred in the 1st layer.
     Caused by error in `draw_group()`:
     ! `draw_quantiles` must be between 0 and 1
 
diff --git a/tests/testthat/_snaps/layer.md b/tests/testthat/_snaps/layer.md
index a3c62a08dd..9e7388aebf 100644
--- a/tests/testthat/_snaps/layer.md
+++ b/tests/testthat/_snaps/layer.md
@@ -29,8 +29,8 @@
 
 # invalid aesthetics throws errors
 
-    Problem computing aesthetics
-    i Error occurred in the 1st layer
+    Problem while computing aesthetics.
+    i Error occurred in the 1st layer.
     Caused by error in `compute_aesthetics()`:
     ! Aesthetics are not valid data columns.
     x The following aesthetics are invalid:
@@ -39,8 +39,8 @@
 
 ---
 
-    Problem mapping statistics to aesthetics
-    i Error occurred in the 1st layer
+    Problem while mapping stat to aesthetics.
+    i Error occurred in the 1st layer.
     Caused by error in `map_statistic()`:
     ! Aesthetics must be valid computed stats.
     x The following aesthetics are invalid:
@@ -49,8 +49,8 @@
 
 # function aesthetics are wrapped with stat()
 
-    Problem computing aesthetics
-    i Error occurred in the 1st layer
+    Problem while computing aesthetics.
+    i Error occurred in the 1st layer.
     Caused by error in `compute_aesthetics()`:
     ! Aesthetics are not valid data columns.
     x The following aesthetics are invalid:
@@ -60,8 +60,8 @@
 
 # computed stats are in appropriate layer
 
-    Problem mapping statistics to aesthetics
-    i Error occurred in the 1st layer
+    Problem while mapping stat to aesthetics.
+    i Error occurred in the 1st layer.
     Caused by error in `map_statistic()`:
     ! Aesthetics must be valid computed stats.
     x The following aesthetics are invalid:
diff --git a/tests/testthat/_snaps/position-jitterdodge.md b/tests/testthat/_snaps/position-jitterdodge.md
index 485d8bbf02..068f546f5b 100644
--- a/tests/testthat/_snaps/position-jitterdodge.md
+++ b/tests/testthat/_snaps/position-jitterdodge.md
@@ -1,7 +1,7 @@
 # position_jitterdodge() fails with meaningful error
 
-    Problem computing positions
-    i Error occurred in the 1st layer
+    Problem while computing position.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `position_jitterdodge()` requires at least one aesthetic to dodge by
 
diff --git a/tests/testthat/_snaps/stat-bin.md b/tests/testthat/_snaps/stat-bin.md
index aabdc610f2..d6a7ca7440 100644
--- a/tests/testthat/_snaps/stat-bin.md
+++ b/tests/testthat/_snaps/stat-bin.md
@@ -1,21 +1,21 @@
 # stat_bin throws error when wrong combination of aesthetic is present
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_bin()` requires an x or y aesthetic.
 
 ---
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_bin()` must only have an x or y aesthetic.
 
 ---
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_bin()` requires a continuous x aesthetic
     x the x aesthetic is discrete.
@@ -55,8 +55,8 @@
 
 # stat_count throws error when both x and y aesthetic present
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_count()` must only have an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-boxplot.md b/tests/testthat/_snaps/stat-boxplot.md
index 2e930ca60b..1f54101fdc 100644
--- a/tests/testthat/_snaps/stat-boxplot.md
+++ b/tests/testthat/_snaps/stat-boxplot.md
@@ -8,8 +8,8 @@
 
 # stat_boxplot errors with missing x/y aesthetics
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_boxplot()` requires an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-count.md b/tests/testthat/_snaps/stat-count.md
index fb62f3233b..51d990c52e 100644
--- a/tests/testthat/_snaps/stat-count.md
+++ b/tests/testthat/_snaps/stat-count.md
@@ -1,14 +1,14 @@
 # stat_count() checks the aesthetics
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_count()` requires an x or y aesthetic.
 
 ---
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_count()` must only have an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-density.md b/tests/testthat/_snaps/stat-density.md
index 66dce9699a..ef29bcb937 100644
--- a/tests/testthat/_snaps/stat-density.md
+++ b/tests/testthat/_snaps/stat-density.md
@@ -1,7 +1,7 @@
 # stat_density works in both directions
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_density()` requires an x or y aesthetic.
 
diff --git a/tests/testthat/_snaps/stat-density2d.md b/tests/testthat/_snaps/stat-density2d.md
index 0aafb0754b..c1bf610cc0 100644
--- a/tests/testthat/_snaps/stat-density2d.md
+++ b/tests/testthat/_snaps/stat-density2d.md
@@ -1,7 +1,7 @@
 # stat_density2d can produce contour and raster data
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `compute_layer()`:
     ! Invalid value of `contour_var` ("abcd")
     i Supported values are "density", "ndensity", and "count".
diff --git a/tests/testthat/_snaps/stat-ecdf.md b/tests/testthat/_snaps/stat-ecdf.md
index 74b2187ce3..e4da4c47f9 100644
--- a/tests/testthat/_snaps/stat-ecdf.md
+++ b/tests/testthat/_snaps/stat-ecdf.md
@@ -1,7 +1,7 @@
 # stat_ecdf works in both directions
 
-    Problem computing statistics
-    i Error occurred in the 1st layer
+    Problem while computing stat.
+    i Error occurred in the 1st layer.
     Caused by error in `setup_params()`:
     ! `stat_ecdf()` requires an x or y aesthetic.