don't include tick info if _either_ text or value is missing, closes #1725, closes #1721

Author: cpsievert

NEWS.md

@@ -5,6 +5,7 @@ This is minor patch release with a few minor bug fixes and updates test expectat
 ## BUG FIXES
 
 * Fixes rendering issues non-HTML **rmarkdown** output formats, which was introduced in the 4.9.2 release (#1702).
+* Fixes a `ggplotly()` bug in axis tick translation (#1725, #1721).
 * `plot_mapbox()` now correctly defaults to a scattermapbox trace (unless z is present, then it defaults to choroplethmapbox) (#1707).
 * `ggplotly()` now correctly resolves overlapping axis tick text in `coord_sf()` (#1673).
 * A false-positive warning is no longer thrown when attempting to cast `toWebGL()` (#1569).

R/ggplotly.R

@@ -693,8 +693,9 @@ gg2list <- function(p, width = NULL, height = NULL,
       tickvals <- rng[[xy]]$break_positions %()% rng[[paste0(xy, ".major")]]
 
       # https://github.com/tidyverse/ggplot2/pull/3566#issuecomment-565085809
-      ticktext <- ticktext[!is.na(ticktext)]
-      tickvals <- tickvals[!is.na(tickvals)]
+      hasTickText <- !(is.na(ticktext) | is.na(tickvals))
+      ticktext <- ticktext[hasTickText]
+      tickvals <- tickvals[hasTickText]
 
       axisObj <- list(
         # TODO: log type?

tests/figs/ggplot-ticks/continuous-x-missing.svg

@@ -190,4 +190,13 @@ test_that("R line breaks are translated to HTML line breaks", {
   )
 })
 
-
+test_that("Missing axis ticks are treated correctly", {
+  # https://github.com/ropensci/plotly/issues/1721
+  p <- ggplot(data = mtcars, aes(x = qsec, y = disp)) + 
+    geom_point() + 
+    scale_x_continuous(
+      breaks = pretty(range(mtcars$qsec), n = 10),
+      labels = pretty(range(mtcars$qsec), n = 10)
+    )
+  expect_doppelganger_built(p, "continuous-x-missing")
+})