Add test_file function

This allows you to have tight iteration when editing a single R or test
file.

Fixes r-lib#1755

NAMESPACE

@@ -134,6 +134,7 @@ export(system_check)
 export(system_output)
 export(test)
 export(test_coverage)
+export(test_file)
 export(uninstall)
 export(unload)
 export(update_packages)

NEWS.md

@@ -1,5 +1,8 @@
 # devtools 1.13.3.9000
 
+* `test_file()` function added to test one or more files from a package
+  (#1755).
+
 * `install_remote()` now uses the repo and type arguments from the remote
   rather than using the argument passed to `...` (#1747).
 

R/test.r

@@ -1,13 +1,17 @@
-#' Execute all \pkg{test_that} tests in a package.
+#' Execute \pkg{test_that} tests in a package.
 #'
 #' `test()` is a shortcut for [testthat::test_dir()].
-#' `test_coverage()` is a shortcut for [covr::package_coverage()].
+#' `test_file` runs `test()` on one or more test files files.
+#' `test_coverage()` is a shortcut for [covr::report()].
 #'
 #' @md
 #' @param pkg package description, can be path or package name. See
 #'   [as.package()] for more information
 #' @param ... additional arguments passed to [testthat::test_dir()] and
 #'   [covr::package_coverage()]
+#' @param file One or more source or test files. If a source file the
+#'   corresponding test file will be run. The default is to use the active file
+#'   in RStudio (if available).
 #' @inheritParams testthat::test_dir
 #' @inheritParams run_examples
 #' @export
@@ -128,3 +132,45 @@ uses_testthat <- function(pkg = ".") {
 
   any(dir.exists(paths))
 }
+
+#' @export
+#' @rdname test
+test_file <- function(file = find_active_file(), ...) {
+  is_source_file <- basename(dirname(file)) == "R"
+
+  has_r_ext <- grepl("\\.[rR]$", file)
+  if (any(!has_r_ext)) {
+    stop("file(s): ",
+         paste0("'", file[!has_r_ext], "'", collapse = ", "),
+         " are not R files", call. = FALSE)
+  }
+
+  file <- basename(file)
+  file[!is_source_file] <- sub("^test-?", "", file[!is_source_file])
+
+  file <- sub("\\.[rR]$", "", file)
+
+  regex <- paste0("^", escape_special_regex(file), "$", collapse = "|")
+
+  test(filter = regex, ...)
+}
+
+find_active_file <- function(arg = "file") {
+  if (!rstudioapi::isAvailable()) {
+    stop("Argument `", arg, "` is missing, with no default", call. = FALSE)
+  }
+  rstudioapi::getSourceEditorContext()$path
+}
+
+find_test_file <- function(file) {
+  dir <- basename(dirname(file))
+  if (dir != "R") {
+    stop("Open file not in `R/` directory", call. = FALSE)
+  }
+
+  if (!grepl("\\.[Rr]$", file)) {
+    stop("Open file is does not end in `.R`", call. = FALSE)
+  }
+
+  file
+}

R/utils.r

@@ -189,3 +189,8 @@ menu <- function(...) {
 file.info <- function(...) {
   base::file.info(...)
 }
+
+escape_special_regex <- function(x) {
+  chars <- c("*", ".", "?", "^", "+", "$", "|", "(", ")", "[", "]", "{", "}", "\\")
+  gsub(paste0("([\\", paste0(collapse = "\\", chars), "])"), "\\\\\\1", x, perl = TRUE)
+}

tests/testthat/test-test.r

@@ -17,3 +17,10 @@ test_that("Filtering works with devtools::test", {
   test("testTest", filter = "dummy", reporter = "stop")
   expect_true(TRUE)
 })
+
+test_that("devtools::test_file works", {
+  expect_error(test_file("testTest/DESCRIPTION"), "are not R files")
+  test_file("testTest/tests/testthat/test-dummy.R", pkg = "testTest", reporter = "stop")
+  test_file("testTest/R/dummy.R", pkg = "testTest", reporter = "stop")
+  expect_true(TRUE)
+})