Calls to mock-objects either constructed using mock() or returned by
local_mock() can keep track of how they were called and functions
mock_call(), mock_arg/s() and mock_n_called() can be used to retrieve
related information.
mock(expr, env = parent.frame())
mock_call(x, call_no = mock_n_called(x))
mock_args(x, call_no = mock_n_called(x))
mock_arg(x, arg, call_no = mock_n_called(x))
mock_n_called(x)Expression to be used as body of the function to be mocked.
Environment used as ancestor to the mock function environment.
Object of class mock_fun to be queried for call and argument
information.
The call number of interest (in case the function was called multiple times).
String-valued argument name to be retrieved.
mock(): a mock_fun object
mock_call(): a call (created by base::match.call())
mock_arg(): the object used as specified function argument
mock_args(): a list of all function arguments used to create a call to
the mock_fun object in question
mock_n_called(): a scalar integer
A mocking function can be created either from a single object to be used
as return value or from an expression which is used as function body. In
both cases, the function signature is inferred from the mock-target.
Furthermore, closures constructed by mock() are able to keep track of
call objects and arguments passed to their respective targets. The
following utility functions are available to query this information:
mock_call(): retrieves the call captured by base::match.call()
mock_arg(): retrieves the value of the argument with name passed as
string-valued argument arg
mock_args(): retrieves a list of all arguments used for calling the
mocked function
mock_n_called(): counts the number of times the mocked function was
called
Calls to mock objects are indexed chronologically and both mock_call()
and mock_args() provide an argument call_no which can be used to specify
which call is of interest, with the default being the most recent (or last)
one.
url <- "https://eu.httpbin.org/get?foo=123"
mk <- mock("mocked request")
dl <- function(x) curl::curl(x)
with_mock(`curl::curl` = mk, dl(url))
#> [1] "mocked request"
mock_call(mk)
#> curl::curl(url = x)
mock_args(mk)
#> $url
#> [1] "https://eu.httpbin.org/get?foo=123"
#>
#> $open
#> [1] ""
#>
#> $handle
#> <curl handle> (empty)
#>
mock_n_called(mk)
#> [1] 1
mk <- mock({
url
})
with_mock(`curl::curl` = mk, dl(url))
#> [1] "https://eu.httpbin.org/get?foo=123"
my_return_val <- "mocked request"
mk <- mock(my_return_val)
with_mock(`curl::curl` = mk, dl(url))
#> [1] "mocked request"