address warnings when shading zero area

NEWS.md

@@ -2,6 +2,9 @@
 
 * The aliases `p_value()` and `conf_int()`, first deprecated 6 years ago, now
   return an error (#530).
+
+* Addresses ggplot2 warnings when shading p-values for test statistics
+  that are outside of the range of the generated distribution (#528).
 
 # infer v1.0.6
 

R/shade_p_value.R

@@ -180,6 +180,8 @@ shade_p_value_term <- function(plot, obs_stat, direction,
   segment_args <- c_dedupl(
     # Not overwritable arguments
     list(
+      # Address length-1 aesthetics warning by providing geom-specific data (#528)
+      data = data.frame(obs_stat = obs_stat),
       # Here `aes()` is needed to force {ggplot2} to include segment in the plot
       mapping = aes(x = obs_stat, xend = obs_stat, y = 0, yend = Inf),
       color = color,
@@ -346,6 +348,12 @@ hist_area <- function(data, obs_stat, direction, yval) {
     right = c(obs_stat, x_extra[x_extra > obs_stat])
   )
 
+  # if area will have area 0, return 0-length tibble to trigger
+  # `ggplot:::empty()` edge case (#528)
+  if (length(x_grid) == 1) {
+    return(tibble::tibble(x = numeric(0), y = numeric(0), dir = character(0)))
+  }
+
   tibble::tibble(x = x_grid, y = curve_fun(x_grid), dir = direction)
 }