Remove what a build and a syntax check leave in the temp directory

.github/workflows/R-CMD-check-wsl.yaml

@@ -21,6 +21,7 @@ jobs:
   WSL-R-CMD-check:
     if: "! contains(github.event.head_commit.message, '[ci skip]')"
     runs-on: windows-latest
+    timeout-minutes: 240
 
     name: windows-latest-WSL2
 

NEWS.md

@@ -87,6 +87,10 @@ model. (#1258)
 loaded with `readRDS()`. Previously it reported them as already compiled and
 calling one failed with a null symbol address, the same defect
 `$init_model_methods()` had before #1157.
+* A build no longer leaves its copy of the Stan program, the C++ generated from
+it and a second copy of the executable in the session's temporary directory.
+Checking syntax and reading a program's variables no longer leave stanc's
+output there either. (#1258)
 * `$log_prob()`, `$grad_log_prob()`, and other model methods are now faster
 after initialization because they avoid repeated stale-binding checks. (#1274)
 * `install_cmdstan()` now offers to copy the `make/local` flags of the

R/build.R

@@ -122,6 +122,9 @@ build_executable <- function(stan_file,
       pattern = "model-", fileext = paste0(".", tools::file_ext(stan_file))
     )
     file.copy(stan_file, source, overwrite = TRUE)
+    withr::defer(unlink(c(
+      source, paste0(strip_ext(source), ".hpp"), cmdstan_ext(strip_ext(source))
+    )))
   }
   hpp_code <- get_standalone_hpp(
     source, c(stanc_inc_paths, stancflags_direct),

R/model.R

@@ -773,9 +773,9 @@ check_syntax_stan_file <- function(stan_file,
   stan_file <- resolve_path(stan_file)
   stanc_options <- assert_valid_stanc_options(stanc_options)
   stanc_options[["allow-undefined"]] <- TRUE
-  stanc_options[["o"]] <- wsl_safe_path(
-    tempfile(pattern = "model-", fileext = ".hpp")
-  )
+  hpp_file <- tempfile(pattern = "model-", fileext = ".hpp")
+  withr::defer(unlink(hpp_file))
+  stanc_options[["o"]] <- wsl_safe_path(hpp_file)
   if (pedantic) {
     stanc_options[["warn-pedantic"]] <- TRUE
   }
@@ -2460,6 +2460,7 @@ run_stanc <- function(stan_file, args, spinner = FALSE) {
 #' @noRd
 stanc_info <- function(stan_file, include_paths = NULL) {
   out_file <- tempfile(fileext = ".json")
+  withr::defer(unlink(out_file))
   run_log <- wsl_compatible_run(
     command = stanc_cmd(),
     args = c(wsl_safe_path(stan_file),

tests/testthat/test-model-rebuild-rules.R

@@ -199,6 +199,20 @@ test_that("a renamed program with a copied executable rebuilds for its name", {
   )))
 })
 
+test_that("a project moved as a whole still reuses its executable", {
+  stan_file <- local_bernoulli()
+  mocked(expect_mock_compile(cmdstan_model(stan_file)))
+
+  moved <- paste0(dirname(stan_file), "-moved")
+  withr::defer(unlink(moved, recursive = TRUE))
+  file.rename(dirname(stan_file), moved)
+
+  mocked(expect_no_mock_compile(expect_interactive_message(
+    cmdstan_model(file.path(moved, basename(stan_file))),
+    "Model executable is up to date!"
+  )))
+})
+
 test_that("a record that cannot be used rebuilds and says why", {
   stan_file <- local_bernoulli()
   mocked(expect_mock_compile(mod <- cmdstan_model(stan_file)))

tests/testthat/test-model-rebuild.R

@@ -270,20 +270,6 @@ test_that("include paths reordered to the same resolution do not rebuild", {
   )
 })
 
-test_that("a project moved as a whole still reuses its executable", {
-  dir_a <- withr::local_tempdir()
-  stan_file_a <- seed_from(
-    canonical_bernoulli_stan, canonical_bernoulli_exe, dir_a
-  )
-  dir_b <- paste0(dir_a, "-moved")
-  withr::defer(unlink(dir_b, recursive = TRUE))
-  file.rename(dir_a, dir_b)
-
-  expect_no_recompilation(
-    cmdstan_model(file.path(dir_b, basename(stan_file_a)))
-  )
-})
-
 test_that("formatting the program invalidates the executable that built it", {
   dir <- withr::local_tempdir()
   stan_file <- write_stan_file(c(
@@ -465,3 +451,10 @@ test_that("a model whose Stan file is gone errors, and its executable can be ado
   adopted <- cmdstan_model(exe_file = mod$exe_file())
   expect_sample_output(adopted$sample(data = data, chains = 1), 1)
 })
+
+test_that("a build leaves only the model's C++ in the temporary directory", {
+  stan_file <- local_program()
+  before <- list.files(tempdir())
+  mod <- cmdstan_model(stan_file)
+  expect_equal(setdiff(list.files(tempdir()), before), basename(mod$hpp_file()))
+})

tests/testthat/test-stan-file-functions.R

@@ -23,6 +23,13 @@ test_that("check_syntax_stan_file() checks a program", {
   expect_true(check_syntax_stan_file(include_model$stan_file, quiet = TRUE))
 })
 
+test_that("check_syntax_stan_file() and variables_stan_file() leave nothing behind", {
+  before <- list.files(tempdir())
+  check_syntax_stan_file(testing_stan_file("bernoulli"), quiet = TRUE)
+  variables_stan_file(testing_stan_file("bernoulli"))
+  expect_equal(list.files(tempdir()), before)
+})
+
 test_that("format_stan_file() formats a program", {
   stan_file <- withr::local_tempfile(
     lines = "parameters {real y;} model {y ~ std_normal();}", fileext = ".stan"