Create a classed error condition

Constructs an error condition object with a custom class, suitable for use with [stop()] to raise typed exceptions that can be caught selectively with [tryCatch()] or [withCallingHandlers()].

Usage

.make_error(error_class, ...)

Arguments

error_class

A character string naming the error class (e.g. `"my_package_error"`). This is prepended to `c("error", "condition")` so that the condition inherits from the base error class.

...

Character strings that are concatenated (with no separator) to form the human-readable error message, analogous to the `...` argument of [stop()].

Value

A condition object of class `c(error_class, "error", "condition")`.

Examples

if (FALSE) { # \dontrun{
# Raise a typed error
stop(.make_error("validation_error", "Value must be positive"))

# Test that a specific error class was raised
tryCatch(
  stop(.make_error("validation_error", "Value must be ", "positive")),
  validation_error = function(e) {
    message("Caught a validation_error: ", conditionMessage(e))
  }
)

# In testthat, assert that the correct error class is thrown
testthat::expect_error(
  stop(.make_error("validation_error", "Value must be positive")),
  class = "validation_error"
)
} # }