diff --git a/R/testing.R b/R/testing.R
index b5db5e23f..2a9cbc9f0 100644
--- a/R/testing.R
+++ b/R/testing.R
@@ -86,6 +86,8 @@ run_test <- function(hook_name,
 #' @param expect_success Whether or not an exit code 0 is expected. This can
 #'   be derived from `std_err`, but sometimes, non-empty stderr does not mean
 #'   error, but just a message.
+#' @param read_only If `TRUE` and `artifacts` are not `NULL`, then assert that hook
+#'   did not modify the artifacts.
 #' @keywords internal
 run_test_impl <- function(path_executable,
                           path_candidate,
diff --git a/man/run_test.Rd b/man/run_test.Rd
index fbc8f4388..f6aa2c84a 100644
--- a/man/run_test.Rd
+++ b/man/run_test.Rd
@@ -14,7 +14,8 @@ run_test(
   artifacts = NULL,
   file_transformer = function(files) files,
   env = character(),
-  expect_success = is.null(std_err)
+  expect_success = is.null(std_err),
+  read_only = FALSE
 )
 }
 \arguments{
@@ -55,6 +56,9 @@ made.}
 \item{expect_success}{Whether or not an exit code 0 is expected. This can
 be derived from \code{std_err}, but sometimes, non-empty stderr does not mean
 error, but just a message.}
+
+\item{read_only}{If \code{TRUE} and \code{artifacts} are not \code{NULL}, then assert that hook
+did not modify the artifacts.}
 }
 \description{
 Tests for the executables used as pre-commit hooks via \code{entrypoint} in
diff --git a/man/run_test_impl.Rd b/man/run_test_impl.Rd
index 534babd0d..e060309b1 100644
--- a/man/run_test_impl.Rd
+++ b/man/run_test_impl.Rd
@@ -13,7 +13,8 @@ run_test_impl(
   artifacts,
   file_transformer,
   env,
-  expect_success
+  expect_success,
+  read_only
 )
 }
 \arguments{
@@ -40,6 +41,9 @@ temporary location and the value is the source of the file.}
 \item{expect_success}{Whether or not an exit code 0 is expected. This can
 be derived from \code{std_err}, but sometimes, non-empty stderr does not mean
 error, but just a message.}
+
+\item{read_only}{If \code{TRUE} and \code{artifacts} are not \code{NULL}, then assert that hook
+did not modify the artifacts.}
 }
 \description{
 Implement a test run