Implement GeomSf$handle_na()

R/geom-sf.R

@@ -96,9 +96,22 @@ GeomSf <- ggproto("GeomSf", Geom,
                     alpha = NA,
                     stroke = 0.5
                   ),
-
-  non_missing_aes = c("size", "shape", "colour"),
 
+  handle_na = function(self, data, params) {
+    type <- sf_types[sf::st_geometry_type(data$geometry)]
+
+    if (all(type == "point")) {
+      non_missing_aes <- c("size", "shape", "colour")
+    } else {
+      non_missing_aes <- character()
+    }
+
+    remove_missing(data, params$na.rm,
+      c(self$required_aes, non_missing_aes),
+      snake_class(self)
+    )
+  },
+
   draw_panel = function(data, panel_params, coord, legend = NULL,
                         lineend = "butt", linejoin = "round", linemitre = 10) {
     if (!inherits(coord, "CoordSf")) {

tests/testthat/test-geom-sf.R

@@ -81,19 +81,36 @@ test_that("geom_sf() removes rows containing missing aes", {
     colour = c("red", NA)
   )
 
-  p <- ggplot(pts) + geom_sf()
+  p1 <- ggplot(pts) + geom_sf()
   expect_warning(
-    expect_identical(grob_xy_length(p + aes(size = size)), c(1L, 1L)),
+    expect_identical(grob_xy_length(p1 + aes(size = size)), c(1L, 1L)),
     "Removed 1 rows containing missing values"
   )
   expect_warning(
-    expect_identical(grob_xy_length(p + aes(shape = shape)), c(1L, 1L)),
+    expect_identical(grob_xy_length(p1 + aes(shape = shape)), c(1L, 1L)),
     "Removed 1 rows containing missing values"
   )
   # default colour scale maps a colour even to a NA, so identity scale is needed to see if NA is removed
   expect_warning(
-    expect_identical(grob_xy_length(p + aes(colour = colour) + scale_colour_identity()),
+    expect_identical(grob_xy_length(p1 + aes(colour = colour) + scale_colour_identity()),
                      c(1L, 1L)),
     "Removed 1 rows containing missing values"
   )
+
+  plgns <- sf::st_sf(
+    geometry = sf::st_sfc(
+      sf::st_polygon(list(rbind(1:2, 2:3, 3:4, 1:2))),
+      sf::st_polygon(list(rbind(1:2, 2:3, 3:4, 1:2)))
+    ),
+    colour = c(1, NA)
+  )
+
+  p2 <- ggplot(plgns) + geom_sf()
+  # colour is not a non_missing_aes for polygons
+  expect_warning(
+    expect_identical(grob_xy_length(p2 + aes(colour = colour) + scale_colour_identity()),
+                     c(8L, 8L)),
+    NA
+  )
+
 })