add test for utf8 check

inst/tinytest/test-utf8.R

@@ -0,0 +1,40 @@
+library(mschart)
+library(officer)
+library(xml2)
+
+unpack_chart <- function(chart){
+
+  pptx_out <- tempfile(fileext = ".pptx")
+  dir_out <- tempfile(pattern = "dir", fileext = "")
+
+  doc <- read_pptx()
+  doc <- add_slide(doc)
+  doc <- ph_with(doc, chart, location = ph_location_type())
+  print(doc, pptx_out)
+  unpack_folder(file = pptx_out, folder = dir_out)
+
+  chart_xml <- list.files(
+    file.path(dir_out, "ppt", "charts"),
+    pattern = "^chart(.*)\\.xml$",
+    full.names = TRUE
+  )
+  attr(dir_out, "chart_xml") <- chart_xml
+  dir_out
+}
+
+test <- browser_data
+test[test$browser=='Opera', 1] <- '\U0001f47d'
+
+chart_01 <- ms_barchart(data = test, x = "browser", y = "value", group = "serie")
+chart_01 <- chart_labels(chart_01, title = "\U0001f47d", xlab = "\U0001f47d")
+
+path <- unpack_chart(chart_01)
+
+chart <- read_xml(attr(path, "chart_xml"))
+txt <- xml_find_all(chart, "//c:title/c:tx/c:rich/a:p/a:r/a:t")
+
+expect_equivalent(xml_text(txt), c("\U0001f47d", "\U0001f47d"))
+
+
+txt_data <- xml_find_all(chart, "//c:ser[1]/c:cat/c:strRef/c:strCache/c:pt")
+expect_equivalent(xml_text(txt_data), c("Android", "Chrome", "Firefox", "IE", "Safari", "\U0001f47d"))