missing start/end columns if spec is passed to bed_merge

[jayhesselberth]

library(valr)

x <- trbl_interval(
  ~chrom, ~start, ~end, ~value,
  "chr1", 100,    200,  100,
  "chr1", 150,    250,  200
)

bed_merge(x, .value = sum(value))
#> # A tibble: 1 x 2
#>   chrom .value
#>   <chr>  <dbl>
#> 1  chr1    300