insert_example_cassette: Use cassettes in examples

In vcr: Record 'HTTP' Calls to Disk

Use cassettes in examples

Description

insert_example_cassette() is a wrapper around insert_cassette() that stores cassettes in ⁠inst/_vcr/⁠. Call it in the first line of your examples (typically wrapped in ⁠\dontshow{}⁠), and call eject_cassette() on the last line.

Run the example manually once to record the vignettte, then it will be replayed during ⁠R CMD check⁠, ensuring that your example no longer uses the internet.

Usage

insert_example_cassette(
  name,
  package,
  record = NULL,
  match_requests_on = NULL,
  serialize_with = NULL,
  preserve_exact_body_bytes = NULL,
  re_record_interval = NULL
)

Arguments

name	The name of the cassette. This is used to name a file on disk, so it must be valid file name.
package	Package name.
record	Record mode. This will be "once" if package is under development, (i.e. loaded by devtools) and "none" otherwise. This makes it easy to record during development and ensure that cassettes HTTP requests are never made on CRAN. To re-record all cassettes, you can delete ⁠inst/_vcr⁠ then run pkgdown::build_reference(lazy = FALSE).
match_requests_on	Character vector of request matchers used to determine which recorded HTTP interaction to replay. The default matches on the "method", "uri", and either "body" (if present) or "body_json" (if the content-type is application/json). The full set of possible values are: method: the HTTP method. uri: the complete request URI, excluding the port. uri_with_port: the complete request URI, including the port. host: the host component of the URI. path: the path component of the URI. query: the query component of the URI. body: the request body. body_json: the request body, parsed as JSON. header: all request headers. If more than one is specified, all components must match in order for the request to match. If not supplied, defaults to c("method", "uri"). Note that the request header and body will only be included in the cassette if match_requests_on includes "header" or "body" respectively. This keeps the recorded request as lightweight as possible.
serialize_with	(string) Which serializer to use: "yaml" (the default), "json", or "qs2".
preserve_exact_body_bytes	(logical) Force a binary (base64) representation of the request and response bodies? By default, vcr will look at the Content-Type header to determine if this is necessary, but if it doesn't work you can set preserve_exact_body_bytes = TRUE to force it.
re_record_interval	(integer) How frequently (in seconds) the cassette should be re-recorded. Default: NULL (not re-recorded).

Examples

# In this example I'm showing the insert and eject commands, but you'd
# usually wrap these in \dontshow{} so the user doesn't see them and
# think that they're something they need to copy.

insert_example_cassette("httpbin-get", package = "vcr")

req <- httr2::request("https://hb.cran.dev/get")
resp <- httr2::req_perform(req)

str(httr2::resp_body_json(resp))

eject_cassette()

vcr documentation built on Aug. 8, 2025, 6:45 p.m.