test(beamer): beamer_presentation() incorporates latex dependencies

tests/testthat/test-beamer_presentation.R

@@ -0,0 +1,32 @@
+test_that("beamer_presentation() incorporates latex dependencies", {
+  expected_dependencies <- c(
+    "\\usepackage{longtable}", # from extra_dependencies
+    "\\usepackage{hyperref}" # from knit_meta
+  )
+
+  extra_dependencies <- list(
+    # do not include non-latex dependencies
+    # as pre processor does not care the kind of extra dependencies
+    latex_dependency("longtable")
+  )
+  knit_meta <- list(
+    latex_dependency("hyperref"),
+    html_dependency_jquery() # pre_processor should remove html dependencies
+  )
+
+  fmt <- beamer_presentation(extra_dependencies = extra_dependencies)
+
+  pandoc_args <- fmt$pre_processor(
+    list(),
+    tempfile(),
+    "static",
+    knit_meta,
+    tempdir(),
+    tempdir()
+  )
+
+  included <- pandoc_args[which(pandoc_args == "--include-in-header") + 1L]
+  expect_length(included, 1L)
+  expect_true(file.exists(included))
+  expect_identical(readLines(included), expected_dependencies)
+})