In gaborcsardi/disposables: Create Disposable R Packages for Testing

knitr::opts_chunk$set(
  comment = "#>",
  tidy = FALSE,
  error = FALSE)

Disposable R packages, for testing purposes

Features

The disposable packages are installed in R's temporary directory, so they are cleaned up at the end of the R session.

disposables cleans up after itself, if an error happens during the installation or loading of the disposable packages. If make_packages() fails because of an error, it leaves to temporary garbage behind. In particular, it cleans up the library path and restores .libPaths(), removes the temporary source package directories, removes the installes packages from lib_dir, and unloads the packages that it loaded before the error.

Installation

Install the package from CRAN:

install.packages("disposables")

Usage

make_packages() creates, installs and loads R packages, it takes named expressions, the names will be used as package names.

library(disposables)
pkgs <- make_packages(
  foo1 = { f <- function() print("hello!") ; d <- 1:10 },
  foo2 = { f <- function() print("hello again!") ; d <- 11:20 }
)

The foo1 and foo2 packages are now loaded.

"package:foo1" %in% search()
"package:foo2" %in% search()

You can dispose them with dispose_packages(). This unloads the packages and deletes them from the library directory.

dispose_packages(pkgs)
"package:foo1" %in% search()
"package:foo2" %in% search()
file.exists(pkgs$lib_dir)

Here is a real example that tests cross-package inheritence of R6 classes.

library(disposables)
library(testthat)
test_that("inheritance works across packages", {

  pkgs <- make_packages(
    imports = "R6",

    ## Code to put in package 'R6testA'
    R6testA = {
      AC <- R6Class(
        public = list(
          x = 1
        )
      )
    },

    ## Code to put in package 'R6testB'
    R6testB = {
      BC <- R6Class(
        inherit = R6testA::AC,
        public = list(
          y = 2
        )
      )
    }

  )

  ## In case of an error below
  on.exit(try(dispose_packages(pkgs), silent = TRUE), add = TRUE)

  ## Now ready for the tests
  B <- BC$new()
  expect_equal(B$x, 1)
  expect_equal(B$y, 2)

})