Stub an http request

Usage

stub_request(method = "get", uri = NULL, uri_regex = NULL)

Arguments

method: (character) HTTP method, one of "get", "post", "put", "patch", "head", "delete", "options" - or the special "any" (for any method)
uri: (character) The request uri. Can be a full or partial uri. webmockr can match uri's without the "http" scheme, but does not match if the scheme is "https". required, unless uri_regex given. See UriPattern for more. See the "uri vs. uri_regex" section
uri_regex: (character) A URI represented as regex. required, if uri not given. See examples and the "uri vs. uri_regex" section

Value

an object of class StubbedRequest, with print method describing the stub.

Details

Internally, this calls StubbedRequest which handles the logic

See stub_registry() for listing stubs, stub_registry_clear() for removing all stubs and remove_request_stub() for removing specific stubs

If multiple stubs match the same request, we use the first stub. So if you want to use a stub that was created after an earlier one that matches, remove the earlier one(s).

Note on wi_th(): If you pass query, values are coerced to character class in the recorded stub. You can pass numeric, integer, etc., but all will be coerced to character.

See wi_th() for details on request body/query/headers and to_return() for details on how response status/body/headers are handled

Note

Trailing slashes are dropped from stub URIs before matching

uri vs. uri_regex

When you use uri, we compare the URIs without query params AND also the query params themselves without the URIs.

When you use uri_regex we don't compare URIs and query params; we just use your regex string defined in uri_regex as the pattern for a call to grepl

Mocking writing to disk

See mocking-disk-writing

Error handling

To construct stubs, one uses stub_request() first - which registers the stub in the stub registry. Any additional calls to modify the stub with for example wi_th() or to_return() can error. In those error cases we ideally want to remove (unregister) the stub because you certainly don't want a registered stub that is not exactly what you intended.

When you encounter an error creating a stub you should see a warning message that the stub has been removed, for example:

stub_request("get", "https://httpbin.org/get") %>%
  wi_th(query = mtcars)
#> Error in `wi_th()`:
#> ! z$query must be of class list or partial
#> Run `rlang::last_trace()` to see where the error occurred.
#> Warning message:
#> Encountered an error constructing stub
#> • Removed stub
#> • To see a list of stubs run stub_registry()

Examples

if (FALSE) { # \dontrun{
# basic stubbing
stub_request("get", "https://httpbin.org/get")
stub_request("post", "https://httpbin.org/post")

# any method, use "any"
stub_request("any", "https://httpbin.org/get")

# list stubs
stub_registry()

# request headers
stub_request("get", "https://httpbin.org/get") %>%
  wi_th(headers = list("User-Agent" = "R"))

# request body
stub_request("post", "https://httpbin.org/post") %>%
  wi_th(body = list(foo = "bar"))
stub_registry()
library(crul)
x <- crul::HttpClient$new(url = "https://httpbin.org")
crul::mock()
x$post("post", body = list(foo = "bar"))

# add expectation with to_return
stub_request("get", "https://httpbin.org/get") %>%
  wi_th(
    query = list(hello = "world"),
    headers = list("User-Agent" = "R")
  ) %>%
  to_return(status = 200, body = "stuff", headers = list(a = 5))

# list stubs again
stub_registry()

# regex
stub_request("get", uri_regex = ".+ample\\..")

# set stub an expectation to timeout
stub_request("get", "https://httpbin.org/get") %>% to_timeout()
x <- crul::HttpClient$new(url = "https://httpbin.org")
res <- x$get("get")

# raise exception
library(fauxpas)
stub_request("get", "https://httpbin.org/get") %>% to_raise(HTTPAccepted)
stub_request("get", "https://httpbin.org/get") %>% to_raise(HTTPAccepted, HTTPGone)

x <- crul::HttpClient$new(url = "https://httpbin.org")
stub_request("get", "https://httpbin.org/get") %>% to_raise(HTTPBadGateway)
crul::mock()
x$get("get")

# pass a list to .list
z <- stub_request("get", "https://httpbin.org/get")
wi_th(z, .list = list(query = list(foo = "bar")))

# just body
stub_request("any", uri_regex = ".+") %>%
  wi_th(body = list(foo = "bar"))
## with crul
library(crul)
x <- crul::HttpClient$new(url = "https://httpbin.org")
crul::mock()
x$post("post", body = list(foo = "bar"))
x$put("put", body = list(foo = "bar"))
## with httr
library(httr)
httr_mock()
POST("https://example.com", body = list(foo = "bar"))
PUT("https://google.com", body = list(foo = "bar"))


# just headers
headers <- list(
  "Accept-Encoding" = "gzip, deflate",
  "Accept" = "application/json, text/xml, application/xml, */*"
)
stub_request("any", uri_regex = ".+") %>% wi_th(headers = headers)
library(crul)
x <- crul::HttpClient$new(url = "https://httpbin.org", headers = headers)
crul::mock()
x$post("post")
x$put("put", body = list(foo = "bar"))
x$get("put", query = list(stuff = 3423234L))

# many responses
## the first response matches the first to_return call, and so on
stub_request("get", "https://httpbin.org/get") %>%
  to_return(status = 200, body = "foobar", headers = list(a = 5)) %>%
  to_return(status = 200, body = "bears", headers = list(b = 6))
con <- crul::HttpClient$new(url = "https://httpbin.org")
con$get("get")$parse("UTF-8")
con$get("get")$parse("UTF-8")

## OR, use times with to_return() to repeat the same response many times
library(fauxpas)
stub_request("get", "https://httpbin.org/get") %>%
  to_return(status = 200, body = "apple-pie", times = 2) %>%
  to_raise(HTTPUnauthorized)
con <- crul::HttpClient$new(url = "https://httpbin.org")
con$get("get")$parse("UTF-8")
con$get("get")$parse("UTF-8")
con$get("get")$parse("UTF-8")

# partial matching
## query parameters
library(httr)
enable()
### matches
stub_request("get", "https://hb.opencpu.org/get") %>%
  wi_th(query = including(list(fruit = "pear"))) %>%
  to_return(body = "matched on partial query!")
resp <- GET("https://hb.opencpu.org/get",
  query = list(fruit = "pear", bread = "scone")
)
rawToChar(content(resp))
### doesn't match
stub_registry_clear()
stub_request("get", "https://hb.opencpu.org/get") %>%
  wi_th(query = list(fruit = "pear")) %>%
  to_return(body = "didn't match, ugh!")
# GET("https://hb.opencpu.org/get",
#  query = list(fruit = "pear", meat = "chicken"))

## request body
### matches - including
stub_request("post", "https://hb.opencpu.org/post") %>%
  wi_th(body = including(list(fruit = "pear"))) %>%
  to_return(body = "matched on partial body!")
resp <- POST("https://hb.opencpu.org/post",
  body = list(fruit = "pear", meat = "chicken")
)
rawToChar(content(resp))
### matches - excluding
stub_request("post", "https://hb.opencpu.org/post") %>%
  wi_th(body = excluding(list(fruit = "pear"))) %>%
  to_return(body = "matched on partial body!")
res <- POST("https://hb.opencpu.org/post",
  body = list(color = "blue")
)
rawToChar(content(res))
# POST("https://hb.opencpu.org/post",
#  body = list(fruit = "pear", meat = "chicken"))

# clear all stubs
stub_registry()
stub_registry_clear()
} # }