Add testcases for Issue stan-dev#765

* Model objects from exe file compiled with opencl fail to sample.
* stan_threads set in makefile not respected

tests/testthat/test-opencl.R

@@ -127,3 +127,13 @@ test_that("error for runtime selection of OpenCL devices if version less than 2.
   )
   reset_cmdstan_version()
 })
+
+test_that("model from exe_file retains open_cl option", {
+  skip_if_not(Sys.getenv("CMDSTANR_OPENCL_TESTS") %in% c("1", "true"))
+  stan_file <- testing_stan_file("bernoulli")
+  mod <- cmdstan_model(stan_file = stan_file, cpp_options = list(stan_opencl = TRUE))
+  mod_from_exe <- cmdstan_model(exe_file = mod$exe_file())
+  expect_sample_output(
+    fit <- mod_from_exe$sample(data = testing_data("bernoulli"), opencl_ids = c(0, 0), chains = 1)
+  )
+})

tests/testthat/test-threads.R

@@ -178,3 +178,22 @@ test_that("correct output when stan_threads not TRUE", {
     fixed = TRUE
   )
 })
+
+test_that('correct output when stan threads set via make local',{
+  #TODO clean this up so no leftover changes to make local
+  file.copy(
+    file.path(cmdstan_path(), 'make', 'local'),
+    file.path(cmdstan_path(), 'make', 'local.save')
+  )
+  on.exit(file.rename(
+    file.path(cmdstan_path(), 'make', 'local.save'),
+    file.path(cmdstan_path(), 'make', 'local')
+  ), add = TRUE, after = FALSE)
+  cmdstan_make_local(cpp_options = list(stan_threads = TRUE))
+  mod <- cmdstan_model(stan_program, force_recompile = TRUE)
+  expect_output(
+    f <- mod$sample(data = data_file_json, parallel_chains = 4, threads_per_chain = 1),
+    "Running MCMC with 4 parallel chains, with 1 thread(s) per chain..",
+    fixed = TRUE
+  )
+})