assert_reactive: Assert that x is reactive

In assertions: Simple Assertions for Beautiful and Customisable Error Messages

Assert that x is reactive

Description

Assert that x is reactive

Usage

assert_reactive(x, msg = NULL, call = rlang::caller_env(), arg_name = NULL)

Arguments

x	An object
msg	A character string containing the error message to display if x is not reactive
call	Only relevant when pooling assertions into multi-assertion helper functions. See cli_abort for details.
arg_name	Advanced use only. Name of the argument passed (default: NULL, will automatically extract arg_name).

Value

invisible(TRUE) if x is a reactive, otherwise aborts with the error message specified by msg

Examples

try({
# Assert that a variable is reactive
x <- shiny::reactive(1)
assert_reactive(x)  # does nothing

# Assert that a variable is not a list
x <- 1
assert_reactive(x)  # stops execution and prints an error message
})

assertions documentation built on April 3, 2025, 5:52 p.m.