Add visual tests for stat_summary

Author: wch

visual_test/stat-summary.r

@@ -0,0 +1,21 @@
+vcontext("stat-summary")
+
+ggplot(mtcars, aes(x = cyl, y = mpg, colour = factor(vs))) + 
+  geom_point() +
+  stat_summary(fun.y = mean, geom="line", size = 2)
+save_vtest("summary with color and lines")
+
+# It is not possible to make this behave as expected without breaking the
+# summary with color and lines, because of the way grouping works with
+# stat_summary.
+ggplot(mtcars, aes(x = cyl, y = mpg)) +
+  geom_point() +
+  stat_summary(fun.data=mean_cl_boot, colour="red", geom="crossbar", width=0.2)
+save_vtest("summary with crossbars, no grouping (looks wrong)")
+
+ggplot(mtcars, aes(x = cyl, y = mpg, group = cyl)) +
+  geom_point() +
+  stat_summary(fun.data=mean_cl_boot, colour="red", geom="crossbar", width=0.2)
+save_vtest("summary with crossbars, manual grouping")
+
+end_vcontext()