Upload file with method POST with httr2 in R

Question

I want to POST a request to upload a file (a png in this case) with httr2 in R.

This example uses upload_file() of the superseded package httr (found in this answer):

library(httr)

media <- tempfile()
png(media, with = 800, height = 600)
plot(cars)
dev.off()

metadata <- tempfile()
writeLines(jsonlite::toJSON(list(title = unbox("My file"))), metadata)

#post
req <- POST("https://httpbin.org/post",
  body = list(
    metadata = upload_file(metadata, type = "application/json; charset=UTF-8"),
    media = upload_file(media, type = "image/png")
  ),
  add_headers("Content-Type" = "multipart/related"),
  verbose()
)

unlink(media)
unlink(metadata)

In the httr2's doc, I could find this example that uses req_body_json:

req <- req_gist(token) %>% 
  req_body_json(list(
    description = "This is my cool gist!",
    files = list(test.R = list(content = "print('Hi!')")),
    public = FALSE
  ))
req %>% req_dry_run()

But this sends some text in the body and I want to upload a file.

What is the equivalent of httr:upload_file in httr2?

Answer 1

As usual, I should look at the doc.

It's the function req_body_file(req, path, type = NULL):

req <- request("https://example.com/api") %>% 
  req_body_file(path = "path/to/file.png")
req %>% req_dry_run()