knitr eng_sxss unit tests

test_sxss.R

library(testthat)

# define code chunks ----
scss <- c("$font-stack:    Helvetica, sans-serif;", "$primary-color: #333;",
          "", "body {", "  font: 100% $font-stack;", "  color: $primary-color;",
          "}")
sass <- c("$font-stack:    Helvetica, sans-serif", "$primary-color: #333",
          "", "body", "  font: 100% $font-stack", "  color: $primary-color")
output_compressed <- '<style type=\"text/css\">\nbody{font:100% Helvetica,sans-serif;color:#333}\n</style>\n'

# simulate options object ----
gen_input <- function(engine, valid = TRUE,
                      echo = FALSE, eval = TRUE, error = TRUE,
                      package = NULL, style = NULL, engine.path = NULL){

  code <- if(engine == "sass") sass else scss
  if(!valid) code <- c(code[1:3], "###", code[4:length(code)])

  list(engine = engine,
       echo = echo, eval = eval, code = code, error = error,
       engine.opts = list(package = package, style = style),
       engine.path = engine.path)

}

# get sass path
path <- sub(".(bat|exe)", "",
            tryCatch(
              system2("where","sass", stdout = TRUE),
              warning = function(w) "sass",
              error = function(e) "sass")
            )


# define tests ----
context("Core CSS rendering")

test_that(
  "Valid CSS is rendered to HTML output with the correct engine",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
  expect_message(t1 <- knitr:::eng_sxss(gen_input("scss")), "^Converting sass with R")
  expect_message(t2 <- knitr:::eng_sxss(gen_input("scss", package = TRUE)), "^Converting sass with R")
  expect_message(t3 <- knitr:::eng_sxss(gen_input("scss", package = FALSE)), "^Converting sass with exec")
  expect_message(t4 <- knitr:::eng_sxss(gen_input("sass")), "^Converting sass with R package")
  expect_message(t5 <- knitr:::eng_sxss(gen_input("sass", package = TRUE)), "^Converting sass with R")
  expect_message(t6 <- knitr:::eng_sxss(gen_input("sass", package = FALSE)), "^Converting sass with exec")
  expect_message(t7 <- knitr:::eng_sxss(gen_input("sass", engine.path = path)), "^Converting sass with exec")
  expect_equal(t1, output_compressed)
  expect_equal(t2, output_compressed)
  expect_equal(t3, output_compressed)
  expect_equal(t4, output_compressed)
  expect_equal(t5, output_compressed)
  expect_equal(t6, output_compressed)
  expect_equal(t7, output_compressed)
}))

test_that(
  "Bad input creates no output (empty char) and warning when error = TRUE",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
    expect_warning(t1 <- knitr:::eng_sxss(gen_input("scss", valid = FALSE)))
    expect_warning(t2 <- knitr:::eng_sxss(gen_input("sass", valid = FALSE)))
    expect_warning(t3 <- knitr:::eng_sxss(gen_input("scss", package = FALSE, valid = FALSE)))
    expect_warning(t4 <- knitr:::eng_sxss(gen_input("sass", package = FALSE, valid = FALSE)))
    expect_equal(t1, "")
    expect_equal(t2, "")
    expect_equal(t3, "")
    expect_equal(t4, "")
  }))

test_that(
  "Bad input throws error when error = FALSE",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
    expect_error(knitr:::eng_sxss(gen_input("scss", valid = FALSE, error = FALSE)))
    expect_error(knitr:::eng_sxss(gen_input("sass", valid = FALSE, error = FALSE)))
    expect_error(knitr:::eng_sxss(gen_input("scss", package = FALSE, valid = FALSE, error = FALSE)))
    expect_error(knitr:::eng_sxss(gen_input("sass", package = FALSE, valid = FALSE, error = FALSE)))
  }))

context("Styling options")

test_that(
  "Invalid style defaults to 'compressed' and gives warning when error = TRUE",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
    expect_warning(t1 <- knitr:::eng_sxss(gen_input("scss", style = "xyz")))
    expect_warning(t2 <- knitr:::eng_sxss(gen_input("scss", package = FALSE, style = "xyz")))
    expect_warning(t3 <- knitr:::eng_sxss(gen_input("sass", style = "xyz")))
    expect_warning(t4 <- knitr:::eng_sxss(gen_input("sass", package = FALSE, style = "xyz")))
    expect_warning(t5 <- knitr:::eng_sxss(gen_input("scss", package = FALSE, style = "nested")))
    expect_warning(t6 <- knitr:::eng_sxss(gen_input("sass", package = FALSE, style = "nested")))
    expect_equal(t1, output_compressed)
    expect_equal(t2, output_compressed)
    expect_equal(t3, output_compressed)
    expect_equal(t4, output_compressed)
    expect_equal(t5, output_compressed)
    expect_equal(t6, output_compressed)
  }))

test_that(
  "Invalid style throws error when error = FALSE",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
    expect_error(knitr:::eng_sxss(gen_input("scss", style = "xyz", error = FALSE)))
    expect_error(knitr:::eng_sxss(gen_input("scss", package = FALSE, style = "xyz", error = FALSE)))
    expect_error(knitr:::eng_sxss(gen_input("sass", style = "xyz", error = FALSE)))
    expect_error(knitr:::eng_sxss(gen_input("sass", package = FALSE, style = "xyz", error = FALSE)))
  }))

context("Other chunk options handled correctly")

test_that(
  "All processing is skipped when eval = FALSE",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
    expect_message(t1 <- knitr:::eng_sxss(gen_input("scss", eval = FALSE)), NA)
    expect_message(t2 <- knitr:::eng_sxss(gen_input("scss", package = TRUE, eval = FALSE)), NA)
    expect_message(t3 <- knitr:::eng_sxss(gen_input("scss", package = FALSE, eval = FALSE)), NA)
    expect_message(t4 <- knitr:::eng_sxss(gen_input("sass", eval = FALSE)), NA)
    expect_message(t5 <- knitr:::eng_sxss(gen_input("sass", package = TRUE, eval = FALSE)), NA)
    expect_message(t6 <- knitr:::eng_sxss(gen_input("sass", package = FALSE, eval = FALSE)), NA)
    expect_equal(t1, "")
    expect_equal(t2, "")
    expect_equal(t3, "")
    expect_equal(t4, "")
    expect_equal(t5, "")
    expect_equal(t6, "")
  }))

test_that(
  "Unprocessed results returned when echo = TRUE",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
    expect_equal(knitr:::eng_sxss(gen_input("scss", package = TRUE, eval = FALSE, echo = TRUE)), paste0(scss, collapse = "\n"))
    expect_equal(knitr:::eng_sxss(gen_input("scss", package = FALSE, eval = FALSE, echo = TRUE)), paste0(scss, collapse = "\n"))
    expect_equal(knitr:::eng_sxss(gen_input("sass", package = TRUE, eval = FALSE, echo = TRUE)), paste0(sass, collapse = "\n"))
    expect_equal(knitr:::eng_sxss(gen_input("sass", package = FALSE, eval = FALSE, echo = TRUE)), paste0(sass, collapse = "\n"))
  }))

test_that(
  "Invalid option to package engine.opt is handled correctly",
  with_mock("knitr:::is_html_output" = function(...) TRUE, {
    expect_warning(t1 <- knitr:::eng_sxss(gen_input("scss", package = "a", error = TRUE)), "package option must be either TRUE or FALSE. Defaulting to TRUE.")
    expect_error(knitr:::eng_sxss(gen_input("scss", package = "a", error = FALSE)), "package option must be either TRUE or FALSE")
    expect_equal(t1, output_compressed)
  }))