make use_precommit() non-blocking for long-lasting hook installation

Author: lorenzwalthert

NEWS.md

@@ -5,13 +5,15 @@ includes switching to R based hook for `readme-rmd-render`, avoiding the
 {usethis} dependency, integration tests via GitHub Actions, auto-updates for 
 used packages, roxygen snippet generation and more. In addition:
 
+* New option `precommit.block_install_hooks` (defaults to `FALSE`) governs
+ if `use_precommit(..., install_hooks = TRUE)` should be blocking until 
+ hooks are installed or not.
 * Always sort `inst/WORDLIST` (#303).
 * rename default branch to *main* (#307).
-
-
 * `style-files` hook gains an argument `--cache-root` that is passed to 
   `options(styler.cache_root = ...)` (#305).
 
+
 # precommit v0.1.3.9012
 
 This is a pre-release for `v0.2.0` and imposes a minimal version requirement 

R/call.R

@@ -2,13 +2,14 @@
 #' @param command The command to issue. A character string of length one.
 #' @param args The command line arguments.
 #' @param ... Arguments passed to [system2()].
+#' @param wait Passed to [system2()].
 #' @return
 #' A list with:
 #' * content of stderr
 #' * content of stdout
 #' * exit status
 #' @keywords internal
-call_and_capture <- function(command, args, ...) {
+call_and_capture <- function(command, args, ..., wait = TRUE) {
   if (length(command) != 1 | !inherits(command, "character")) {
     rlang::abort("The command must be a character string of length 1.")
   }
@@ -23,7 +24,7 @@ call_and_capture <- function(command, args, ...) {
     ))
   }
   exit_status <- suppressWarnings(
-    system2(command, args, ..., stdout = stdout, stderr = stderr)
+    system2(command, args, ..., wait = wait, stdout = stdout, stderr = stderr)
   )
   stderr <- readLines(stderr)
   if (isTRUE(any(grepl("error", stderr, ignore.case = TRUE)))) {
@@ -53,15 +54,17 @@ call_and_capture <- function(command, args, ...) {
 #' ensure an executable to runs successfully) or, if the installation method was
 #' not conda, as a plain bash command.
 #' @param ... Arguments passed to the command line call `pre-commit`.
+#' @param wait Passed to [base::system2()].
 #' @keywords internal
-call_precommit <- function(...) {
+call_precommit <- function(..., wait = TRUE) {
   if (is_conda_installation()) {
     call_and_capture(
       reticulate::conda_binary(),
-      c("run", "-n", "r-precommit", path_precommit_exec(), ...)
+      c("run", "-n", "r-precommit", path_precommit_exec(), ...),
+      wait = wait
     )
   } else {
-    call_and_capture(path_precommit_exec(), c(...))
+    call_and_capture(path_precommit_exec(), c(...), wait = wait)
   }
 }
 

R/install.R

@@ -73,12 +73,16 @@ update_impl <- function() {
 }
 
 install_repo <- function(root, install_hooks, legacy_hooks) {
+  wait_for_hook_installation <- getOption(
+    "precommit.block_install_hooks", FALSE
+  )
   withr::with_dir(root, {
     remove_usethis_readme_hook()
     out <- call_precommit(
       "install",
       if (install_hooks) "--install-hooks",
-      if (legacy_hooks == "remove") "--overwrite"
+      if (legacy_hooks == "remove") "--overwrite",
+      wait = wait_for_hook_installation
     )
     if (out$exit_status == 0) {
       if (any(grepl("Use -f to use only pre-commit.", out$stdout, fixed = TRUE))) {
@@ -102,7 +106,15 @@ install_repo <- function(root, install_hooks, legacy_hooks) {
           ))
         }
       } else {
-        cli::cli_alert_success("Sucessfully installed pre-commit for repo.")
+        if (wait_for_hook_installation) {
+          cli::cli_alert_success("Sucessfully installed pre-commit for repo.")
+        } else {
+          cli::cli_alert_info(paste0(
+            "Installing hooks in non-blocking background process.",
+            " If you experience problems or prefer a blocking process, use ",
+            '{.code options("precommit.block_install_hooks" = TRUE)}.'
+          ))
+        }
       }
     } else {
       cli::cli_alert_danger("Failed to install pre-commit for repo.")

R/zzz.R

@@ -1,7 +1,8 @@
 .onLoad <- function(libname, pkgname) {
   op <- options()
   op.precommit <- list(
-    precommit.executable = path_derive_precommit_exec()
+    precommit.executable = path_derive_precommit_exec(),
+    precommit.block_install_hooks = FALSE
   )
   toset <- !(names(op.precommit) %in% names(op))
   if (any(toset)) options(op.precommit[toset])