tests/testthat/test-text.R

In mdecorde/RSvgDevice: An 'SVG' Graphics Device

library(xml2)

test_that("par(cex) affects strwidth", {
  xmlSVG({
    plot.new()
    w1 <- strwidth("X")
    par(cex = 4)
    w4 <- strwidth("X")
  })
  expect_equal(w4 / w1, 4, tolerance = 1e-3)
})

test_that("cex affects strwidth", {
  inlineSVG(height = 7, width = 7, {
    plot.new()
    w1 <- strwidth("X")
    w4 <- strwidth("X", cex = 4)
  })
  expect_equal(w4 / w1, 4, tolerance = 1e-3)
})

test_that("special characters are escaped", {
  x <- xmlSVG({
    plot.new()
    text(0.5, 0.5, "<&>")
  })
  # xml_text unescapes for us - this still tests that the
  # file parses, which it wouldn't otherwise
  expect_equal(xml_text(xml_find_first(x, ".//text")), "<&>")
})

test_that("utf-8 characters are preserved", {
  skip_on_os("windows") # skip because of xml2 buglet
  skip_if_not(l10n_info()$`UTF-8`)

  x <- xmlSVG({
    plot.new()
    text(0.5, 0.5, "\u00b5")
  })
  # xml_text unescapes for us - this still tests that the
  # file parses, which it wouldn't otherwise
  expect_equal(xml_text(xml_find_first(x, ".//text")), "\u00b5")
})

test_that("special characters are escaped", {
  x <- xmlSVG({
    plot.new()
    text(0.5, 0.5, "a", col = "#113399")
  })
  # xml_text unescapes for us - this still tests that the
  # file parses, which it wouldn't otherwise
  expect_equal(style_attr(xml_find_first(x, ".//text"), "fill"), "#113399")
})

test_that("default point size is 12", {
  x <- xmlSVG({
    plot.new()
    text(0.5, 0.5, "a")
  })
  expect_equal(style_attr(xml_find_first(x, ".//text"), "font-size"), "12.00px")
})

test_that("cex generates fractional font sizes", {
  x <- xmlSVG({
    plot.new()
    text(0.5, 0.5, "a", cex = 0.1)
  })
  expect_equal(style_attr(xml_find_first(x, ".//text"), "font-size"), "1.20px")
})

test_that("a symbol has width greater than 0", {
  xmlSVG({
    plot.new()
    strw <- strwidth(expression(symbol("\042")))
  })
  expect_lt(.Machine$double.eps, strw)
})

test_that("strwidth and height correctly computed", {
  svglite("test-text.svg", 4, 4, user_fonts = bitstream)
  on.exit(dev.off())

  plot.new()
  str <- "This is a string"
  text(0.5, 0.5, str)

  h <- strheight(str)
  w <- strwidth(str)

  rect(0.5 - w / 2, 0.5 - h / 2, 0.5 + w / 2, 0.5 + h / 2)
})

test_that("strwidth has fallback for unknown glyphs", {
  xmlSVG(user_fonts = bitstream, {
    plot.new()
    w <- strwidth("正規分布")
  })
  expect_true(w > 0)
})