Fix #2415: variable named 'group' now shown in tooltip

Author: cpsievert

NEWS.md

@@ -7,6 +7,7 @@
 ## Bug fixes
 
 * `plotly_build()` now works with `ggmatrix` objects (e.g., from `GGally::ggpairs()`). (#2447)
+* Closed #2415: `ggplotly()` now shows variables named 'group' in tooltips when mapped to aesthetics like `colour`.
 
 # plotly 4.11.0
 

R/layers2traces.R

@@ -56,8 +56,10 @@ layers2traces <- function(data, prestats_data, layout, p) {
       if (!aesName %in% names(x)) next
       # TODO: should we be getting the name from scale_*(name) first?
       varName <- y[[i]]
-      # "automatically" generated group aes is not informative
-      if (identical("group", unique(varName, aesName))) next
+      # Skip auto-generated group aesthetic (where both aes name and var name are "group"),
+      # but allow: (1) variables named "group" mapped to other aesthetics like colour,
+      # and (2) other variables mapped to the "group" aesthetic
+      if (identical(aesName, "group") && identical(varName, "group")) next
       # add a line break if hovertext already exists
       if ("hovertext" %in% names(x)) x$hovertext <- paste0(x$hovertext, br())
       # text aestheic should be taken verbatim (for custom tooltips)

tests/testthat/test-ggplot-tooltip.R

@@ -119,3 +119,19 @@ test_that("Hoverinfo is only displayed if no tooltip variables are present", {
   expect_true(all(grepl("^label", L$data[[2]]$text)))
 })
 
+test_that("variable named 'group' is shown in tooltip when mapped to aesthetic (#2415)", {
+  # When a user has a column named "group" and maps it to colour,
+  # it should appear in the tooltip
+  df <- data.frame(
+    x = 1:6,
+    y = 1:6,
+    group = rep(c("A", "B"), each = 3)
+  )
+  p <- ggplot(df, aes(x, y, colour = group)) + geom_point()
+  L <- plotly_build(ggplotly(p))$x
+  # Check that "group: A" or "group: B" appears in the tooltip text
+  txt <- unlist(lapply(L$data, function(d) d$text))
+  expect_true(any(grepl("group: A", txt)))
+  expect_true(any(grepl("group: B", txt)))
+})
+