Missing arrival/departure_time entries are filled with 00:00:00

[dhersz]

Hi. I've noticed that read_gtfs() fills missing arrival/departure_time (spec compliant) with 00:00:00. Take the following Google's example feed (https://developers.google.com/transit/gtfs/examples/gtfs-feed), which is included in gtfstools for testing purposes:

path <- system.file("extdata/ggl_gtfs.zip", package = "gtfstools")

gtfs <- tidytransit::read_gtfs(path)

# tidytransit fills empty arrival/departure times with 00'00"
gtfs$stop_times[, c("trip_id", "arrival_time", "departure_time", "stop_id")]
#> # A tibble: 11 × 4
#>    trip_id arrival_time departure_time stop_id
#>    <chr>   <time>       <time>         <chr>  
#>  1 AWE1    06'10"       06'10"         S1     
#>  2 AWE1    00'00"       00'00"         S2     
#>  3 AWE1    06'20"       06'30"         S3     
#>  4 AWE1    00'00"       00'00"         S5     
#>  5 AWE1    06'45"       06'45"         S6     
#>  6 AWD1    06'10"       06'10"         S1     
#>  7 AWD1    00'00"       00'00"         S2     
#>  8 AWD1    06'20"       06'20"         S3     
#>  9 AWD1    00'00"       00'00"         S4     
#> 10 AWD1    00'00"       00'00"         S5     
#> 11 AWD1    06'45"       06'45"         S6

The issue persists when saving the GTFS object to disk with tidytransit::write_gtfs(), in which case the 00'00" entries are saved as 00:00:00. MobilityData's GTFS Validator considers this an error, as we can see from the code below (you'll need to use the dev version of gtfstools for that¹ [if running the code interactively, the function will open a validation report in HTML format, but I'll include the error in the snippet below anyway]):

# results in validation error using MobilityData gtfs validator

validator_path <- gtfstools::download_validator(tempdir())
output_dir <- tempfile()
gtfstools::validate_gtfs(gtfs, output_dir, validator_path)

result_json <- file.path(output_dir, "report.json")
result_json <- jsonlite::read_json(result_json)

error <- result_json$notices[[4]]

error$code
#> [1] "stop_time_with_arrival_before_previous_departure_time"
data.table::rbindlist(error$sampleNotices)
#>    csvRowNumber prevCsvRowNumber tripId arrivalTime departureTime
#> 1:            3                2   AWE1    00:00:00      00:06:10
#> 2:            5                4   AWE1    00:00:00      00:06:30
#> 3:            8                7   AWD1    00:00:00      00:06:10
#> 4:           10                9   AWD1    00:00:00      00:06:20

I don't know how to handle this case with {hms}, but I'd say that representing missing dates with NA seems to be the best strategy. gtfstools represents dates as strings, so missing dates are represented as "", but I'm not sure if something like that is possible with hms objects.

Footnotes

1. Testing if validator_gtfs() worked with tidygtfs objects was exactly how I found this behavior :) ↩

[polettif]

Thanks for pointing this out @dhersz

This is indeed unexpected behavior and I think tidytransit did use NA for missing times at some point in the past... Apparently that's not the case anymore so time to fix it :)