Issue #359 for jitter layer (#560)

* fixes #559

* add test

* news

Author: grantmcdermott

NEWS.md

@@ -25,6 +25,8 @@ where the formatting is also better._
 
 - Jittered plots now support Date/POSIXt axes. Thanks to @wachtermh for the bug
   report and @vincentarelbundock for the code contribution. (#327)
+- `tinyplot_add(type = "jitter")` no longer errors when layered on top of
+  boxplot, violin, or similar categorical plot types. (#560 @grantmcdermott)
 
 ### Internals
 

R/align_layer.R

@@ -34,6 +34,8 @@ align_layer = function(settings) {
     } else if (!is.null(names(xlabs_layer))) {
       # Case 2: match implicit integer -> label mapping (e.g., lines added to errorbars)
       if (setequal(names(xlabs_layer), names(xlabs_orig))) {
+        # If mappings already agree and no dodge, no realignment needed
+        if (identical(xlabs_layer, xlabs_orig) && is.null(settings$dodge)) return(invisible())
         orig_order = xlabs_orig[names(xlabs_layer)[settings$datapoints[["x"]]]]
         x_layer = settings$datapoints[["x"]]
         if (is.null(settings$dodge)) {
@@ -55,4 +57,3 @@ align_layer = function(settings) {
     }
   }
 }
-

inst/tinytest/_tinysnapshot/tinyplot_add_jitter_on_violin.svg

@@ -93,3 +93,12 @@ f = function() {
   tinyplot_add(type = "lm")
 }
 expect_snapshot_plot(f, label = "tinyplot_add_no_recursive_margins")
+
+
+# jitter layer on top of boxplot (#559)
+set.seed(42)
+f = function() {
+  tinyplot(Sepal.Length ~ Species, data = iris, type = "violin")
+  tinyplot_add(type = "jitter", cex = 0.5, alpha = 0.3)
+}
+expect_snapshot_plot(f, label = "tinyplot_add_jitter_on_violin")