transit_network_to_sf() can generate routes with invalid geometries

[rafapereirabr]

Brief description of the problem:

The output of transit_network_to_sf() can generate routes with invalid geometries.

Reproducible example here

library(r5r)
library(ggplot2)
library(sf)

# build network
data_path <- system.file("extdata/poa", package = "r5r")
r5r_core <- setup_r5(data_path = data_path, verbose = FALSE)

# extract public transport network
transit_net <- transit_network_to_sf(r5r_core)


# stops Ok
head(transit_net$stops)

ggplot() +
  geom_sf(data = transit_net$stops, color='gray85') +
  theme_void()


# routes ERROR
head(transit_net$routes)

ggplot() +
  geom_sf(data = transit_net$routes, color='gray85') +
  theme_void()

> Error in CPL_geos_is_empty(st_geometry(x)) : 
>   Evaluation error: IllegalArgumentException: point array must contain 0 or >1 elements.

suggested solution

We should check whether there are any invalid route goemetries and fixed them before returning the ouput.

if( any(FALSE, sf::st_is_valid(transit_net$routes)) ){
  transit_net$routes <- st_make_valid(transit_net$routes)
}