Adding layers makes tooltips disappear

Hi there,

I'm experiencing the same issue as @borenstein, referenced here: Adding layer makes tool tips disappear. Someone asked @borenstein to post the issue here but I didn't see a record of it. Here's a shorter reproducible example and summary; please note their solution (comparing data on hover) doesn't work in my use case (not shown here).

I want to create a plot where users can hover over a map and a tooltip for a single layer appears, for example, showing the names of US counties, with state boundaries overlaid on the map. If your mouse is "far" from a state boundary, the tooltip appears. However, if you are "close" (e.g., southeastern edge of map), the tooltip does not appear.

I've tried identifying the traces that contain parts of my plot that I don't want to show tooltips for - as in these stack overflow posts:

• ggplotly - only return tooltip hover text on certain geom objects

• Disable hover information for a specific layer (geom) of plotly

But, it doesn't work.

library(plotly)
library(tidyverse)

### New England: *sometimes* shows tool tips
new_england <- c("maine", "new hampshire", "vermont", "massachusetts", "connecticut", "rhode island")

b <- ggplot2::map_data("state") %>%
  filter(region %in% new_england)

a <- data.frame(group = seq(3085), val = rnorm(3085)) %>%
  left_join(ggplot2::map_data("county"), by = "group") %>%
  filter(region %in% new_england)

p <- ggplot(a, aes(long, lat, group = group)) +
  geom_polygon(aes(fill = val, text = subregion)) +
  geom_path(data = b, color = "black")

ggplotly(p, tooltip="text")

Tagging @MountainCedar so they know I've filed an issue about this.

首先运行提供的 ggplotly 可复现示例，并比较靠近和远离州边界时的悬停行为。跟踪分层的多边形和路径 trace 如何处理 tooltip 选择；当靠近边界时仍可使用县名 tooltip，且不需要采用所提议的 workaround 时，即可视为完成。issue 中没有指定文件或测试，因此定位相关的 hover 代码并添加回归覆盖需要熟悉项目。