test_add_to_desc <- function(str, msg = "Adding 'dittodb' to Suggests") {
  f <- tempfile()
  cat(str, file = f)
  expect_message(add_dittodb_to_desc(f), msg)
  setNames(read.dcf(f, keep.white = "Suggests")[, "Suggests"], NULL)
}

test_that("add to desc adds Suggests if not present", {
  expect_identical(test_add_to_desc("Title: Foo"), "dittodb")
})

test_that("add to desc adds Suggests if present but empty", {
  expect_identical(test_add_to_desc("Suggests:"), "dittodb")
})

test_that("add to desc adds Suggests inline", {
  expect_identical(test_add_to_desc("Suggests: pkg"), "dittodb, pkg")
  expect_identical(
    test_add_to_desc("Suggests: pkg, alpha (>= 2.0.0)"),
    "alpha (>= 2.0.0), dittodb, pkg"
  )
})

desc_suggests_one_multiline <- "Title: Foo
Suggests:
    pkg
"
desc_suggests_two_multiline <- "Title: Foo
Suggests:
    pkg,
    alpha (>= 2.0.0)
"
desc_suggests_two_uneven <- "Title: Foo
Suggests: pkg,
    alpha (>= 2.0.0)
"

test_that("add to desc adds Suggests multiline", {
  expect_identical(
    test_add_to_desc(desc_suggests_one_multiline),
    "\n    dittodb,\n    pkg"
  )
  expect_identical(
    test_add_to_desc(desc_suggests_two_multiline),
    "\n    alpha (>= 2.0.0),\n    dittodb,\n    pkg"
  )
  expect_identical(
    test_add_to_desc(desc_suggests_two_uneven),
    "alpha (>= 2.0.0),\n    dittodb,\n    pkg"
  )
})

test_that("add to desc doesn't add if already present", {
  expect_identical(test_add_to_desc("Suggests: dittodb", msg = NA), "dittodb")
  expect_identical(
    test_add_to_desc("Suggests: pkg, dittodb", msg = NA),
    "pkg, dittodb"
  )
})

expect_added_to_helper <- function(str, msg = "Adding library\\(dittodb\\)") {
  f <- tempfile()
  cat(str, file = f)
  expect_message(add_dittodb_to_helper(f), msg)
  expect_true(any(grepl("library(dittodb)", readLines(f), fixed = TRUE)))
}

test_that("add to helper creates file if doesn't exist", {
  f <- tempfile()
  expect_false(file.exists(f))
  testthat_transition(
    expect_message(add_dittodb_to_helper(f), "Creating"),
    expect_message(expect_message(add_dittodb_to_helper(f), "Creating"), "Adding library")
  )
  expect_identical(readLines(f), "library(dittodb)")
})

test_that("add to helper adds", {
  expect_added_to_helper("")
  expect_added_to_helper("library(pkg)\n")
})

test_that("add to helper doesn't duplicate", {
  expect_added_to_helper("library(dittodb)\n", msg = NA)
})

test_that("use_dittodb integration test", {
  testpkg <- tempfile()
  dir.create(testpkg)
  expect_error(use_dittodb(testpkg), "is not an R package directory")

  desc <- file.path(testpkg, "DESCRIPTION")
  cat("Title: Foo\n", file = desc)
  helper <- file.path(testpkg, "tests", "testthat", "helper.R")
  testthat_transition(
    expect_message(use_dittodb(testpkg)),
    expect_message(expect_message(expect_message(use_dittodb(testpkg))))
  )
  expect_identical(readLines(desc), c("Title: Foo", "Suggests: dittodb"))
  expect_identical(readLines(helper), "library(dittodb)")
  # It does nothing if you the package already uses dittodb
  expect_message(use_dittodb(testpkg), NA)
})