Fix missing java runtime (#38)

* fix java_check if runtime missing
* fix mock of java_check

Author: jonathanvoelkle

R/selenium.R

@@ -142,7 +142,7 @@ java_check <- function() {
   if (identical(unname(javapath), "")) {
     stop("PATH to JAVA not found. Please check JAVA is installed.")
   }
-  java_version <- suppressWarnings(system2(Sys.which("java"), "-version", stdout = TRUE, stderr = TRUE))
+  java_version <- suppressWarnings(system2(javapath, "-version", stdout = TRUE, stderr = TRUE))
   if (!is.null(attr(java_version, "status"))) {
     stop(paste(java_version, collapse = "\n"))
   }

tests/testthat/test-selenium.R

@@ -78,10 +78,9 @@ test_that("errorIfVersionNotFound", {
     list_versions = mock_binman_list_versions_selenium,
   )
   local_mocked_bindings(
-    Sys.which = function(...) {
+    java_check = function(...) {
       "im here"
     },
-    .package = "base"
   )
 
   expect_error(