Allow 'weight' to be dropped in stats

NEWS.md

@@ -1,5 +1,8 @@
 # ggplot2 (development version)
 
+* Fixed spurious warnings when the `weight` was used in `stat_bin_2d()`, 
+  `stat_boxplot()`, `stat_contour()`, `stat_bin_hex()` and `stat_quantile()`
+  (@teunbrand, #5216).
 * Various type checks and their messages have been standardised 
   (@teunbrand, #4834).
 * The `layer_data()`, `layer_scales()` and `layer_grob()` now have the default

R/stat-bin2d.R

@@ -84,7 +84,9 @@ StatBin2d <- ggproto("StatBin2d", Stat,
     out$density <- out$count / sum(out$count, na.rm = TRUE)
     out$ndensity <- out$density / max(out$density, na.rm = TRUE)
     out
-  }
+  },
+
+  dropped_aes = "weight" # No longer available after transformation
 )
 
 dual_param <- function(x, default = list(x = NULL, y = NULL)) {

R/stat-binhex.R

@@ -60,6 +60,9 @@ StatBinhex <- ggproto("StatBinhex", Stat,
     out$value <- NULL
 
     out
-  }
+  },
+
+  # weight is no longer available after transformation
+  dropped_aes = "weight"
 )
 

R/stat-boxplot.R

@@ -51,7 +51,7 @@ StatBoxplot <- ggproto("StatBoxplot", Stat,
   non_missing_aes = "weight",
   # either the x or y aesthetic will get dropped during
   # statistical transformation, depending on the orientation
-  dropped_aes = c("x", "y"),
+  dropped_aes = c("x", "y", "weight"),
   setup_data = function(self, data, params) {
     data <- flip_data(data, params$flipped_aes)
     data$x <- data$x %||% 0

R/stat-contour.R

@@ -90,7 +90,8 @@ StatContour <- ggproto("StatContour", Stat,
 
   required_aes = c("x", "y", "z"),
   default_aes = aes(order = after_stat(level)),
-  dropped_aes = "z", # z gets dropped during statistical transformation
+  # z and weight get dropped during statistical transformation
+  dropped_aes = c("z", "weight"),
 
   setup_params = function(data, params) {
     params$z.range <- range(data$z, na.rm = TRUE, finite = TRUE)
@@ -120,7 +121,8 @@ StatContourFilled <- ggproto("StatContourFilled", Stat,
 
   required_aes = c("x", "y", "z"),
   default_aes = aes(order = after_stat(level), fill = after_stat(level)),
-  dropped_aes = "z", # z gets dropped during statistical transformation
+  # z and weight get dropped during statistical transformation
+  dropped_aes = c("z", "weight"),
 
   setup_params = function(data, params) {
     params$z.range <- range(data$z, na.rm = TRUE, finite = TRUE)

R/stat-quantilemethods.R

@@ -96,7 +96,10 @@ StatQuantile <- ggproto("StatQuantile", Stat,
       method.args = method.args
     )
     vec_rbind0(!!!result)
-  }
+  },
+
+  # weight is no longer available after transformation
+  dropped_aes = "weight"
 )
 
 quant_pred <- function(quantile, data, method, formula, weight, grid,