Csv serializer (#520)

Co-authored-by: pachamaltese <pachamaltese@users.noreply.github.com>
Co-authored-by: Barret Schloerke <barret@rstudio.com>

DESCRIPTION

@@ -40,7 +40,8 @@ Suggests:
     htmlwidgets,
     visNetwork,
     analogsea (>= 0.7.0),
-    later
+    later,
+    readr
 Remotes:
     rstudio/swagger
 Collate:
@@ -68,6 +69,7 @@ Collate:
     'post-parsers.R'
     'response.R'
     'serializer-content-type.R'
+    'serializer-csv.R'
     'serializer-html.R'
     'serializer-htmlwidget.R'
     'serializer-rds.R'

NAMESPACE

@@ -26,6 +26,7 @@ export(plumb)
 export(plumber)
 export(randomCookieKey)
 export(serializer_content_type)
+export(serializer_csv)
 export(serializer_html)
 export(serializer_htmlwidget)
 export(serializer_json)

NEWS.md

@@ -1,5 +1,11 @@
 plumber (version)
 --------------------------------------------------------------------------------
+
+### New features
+
+* CSV (UTF-8) serialization (@pachamaltese, #520)
+* SVG (UTF-8) serialization (@pachamaltese, #398)
+
 ### Bug fixes
 
 * Fix `plumb()` function when `plumb()`ing a directory so that `plumber.R` is

R/serializer-csv.R

@@ -0,0 +1,20 @@
+#' @rdname serializers
+#' @export
+serializer_csv <- function(...) {
+  if (!requireNamespace("readr", quietly = TRUE)) {
+    stop("`readr` must be installed for `serializer_csv` to work")
+  }
+
+  function(val, req, res, errorHandler) {
+    tryCatch({
+      res$setHeader("Content-Type", "text/plain; charset=UTF-8")
+      res$body <- readr::format_csv(val, ...)
+      return(res$toResponse())
+    }, error = function(e){
+      errorHandler(req, res, e)
+    })
+  }
+}
+
+#' @include globals.R
+.globals$serializers[["csv"]] <- serializer_csv

tests/testthat/test-serializer-csv.R

@@ -0,0 +1,36 @@
+context("CSV serializer")
+
+test_that("CSV serializes properly", {
+  skip_if_not_installed("readr")
+
+  d <- data.frame(a=1, b=2, c="hi")
+  val <- serializer_csv()(d, data.frame(), PlumberResponse$new(), stop)
+  expect_equal(val$status, 200L)
+  expect_equal(val$headers$`Content-Type`, "text/plain; charset=UTF-8")
+  expect_equal(val$body, readr::format_csv(d))
+
+  d <- data.frame(a=1, b=2, c="hi", na=NA)
+  val <- serializer_csv()(d, data.frame(), PlumberResponse$new(), stop)
+  expect_equal(val$status, 200L)
+  expect_equal(val$headers$`Content-Type`, "text/plain; charset=UTF-8")
+  expect_equal(val$body, readr::format_csv(d, na = "NA"))
+
+  d <- data.frame(a=1, b=2, c="hi", na=NA)
+  val <- serializer_csv(na = 'string')(d, data.frame(), PlumberResponse$new(), stop)
+  expect_equal(val$status, 200L)
+  expect_equal(val$headers$`Content-Type`, "text/plain; charset=UTF-8")
+  expect_equal(val$body, readr::format_csv(d, na = 'string'))
+})
+
+test_that("Errors call error handler", {
+  skip_if_not_installed("readr")
+
+  errors <- 0
+  errHandler <- function(req, res, err){
+    errors <<- errors + 1
+  }
+
+  expect_equal(errors, 0)
+  serializer_csv()(parse(text="hi"), data.frame(), PlumberResponse$new("csv"), err = errHandler)
+  expect_equal(errors, 1)
+})