ggplot2 font family changes are not reflected by expect_doppelganger #158
Description
See https://stackoverflow.com/questions/79784967/, largely reproduced below.
In creating unit tests for an r package that provides a custom ggplot2 theme, I've noticed that the snapshots created by vdiffr::expect_doppelganger() aren't reflecting font family changes that work in interactive testing.
a toy package that uses testthat has two files:
R/fonty_theme.R
# a theme provided by the package
fonty_theme <- function(base_family = ""){
thm <- ggplot2::theme_minimal(base_family = base_family)
return(thm)
}
# test helper to create base plot
base_plot <- function() {
ggplot2::ggplot(mtcars, ggplot2::aes(mpg, wt)) +
ggplot2::geom_point() +
ggplot2::labs(
x = "Miles per Gallon (MPG)",
y = "Weight (1000 lbs)"
) +
ggplot2::theme_dark()
}
and tests/testthat/test-fonty_theme.R
test_that("fonty_theme works with default family", {
vdiffr::expect_doppelganger("fonty_theme default", {
base_plot() + fonty_theme()
})
})
test_that("fonty_theme works with mono", {
vdiffr::expect_doppelganger("fonty_theme mono", {
base_plot() + fonty_theme("mono")
})
})
test_that("fonty_theme works with serif", {
vdiffr::expect_doppelganger("fonty_theme serif", {
base_plot() + fonty_theme("serif")
})
})after running devtools::load_all("."), interactive testing with base_plot() + fonty_theme("mono") produces the expected plot with monospaced font:
But when you test the package with devtools::test() and inspect the snapshots snapshots produced by expect_doppelganger() saved in testhat\_snaps\fonty_theme\, the snapshot fonty-theme-mono.svg is using a serif font. Indeed the snapshots for all three test cases are identical, all using serif font.
