code coverage with covr for a project which is not an R package

code_cov_for_project.R

# open Rproj with packrat
# restart R session

library("testthat")
source("libraries.R")

packrat::with_extlib(
  c("rex", "covr", "DT"), {
    library("rex")
    library("covr")
    library("DT")
    covr::shine(covr::file_coverage(
      list.files("src", full.names = TRUE),
      list.files("test", full.names = TRUE)
    ), file = file.path(tempdir(), "code_coverage_report.html"))
  }
)