Allow overriding verbosity default via env var KORAP_VERBOSE

Change-Id: I8a2e32f24c22f2039b335cd000c610ba5ff3da08
diff --git a/tests/testthat/test-verbose-env.R b/tests/testthat/test-verbose-env.R
new file mode 100644
index 0000000..141c0dc
--- /dev/null
+++ b/tests/testthat/test-verbose-env.R
@@ -0,0 +1,21 @@
+test_that("KORAP_VERBOSE overrides verbose default and is restorable", {
+  old <- Sys.getenv("KORAP_VERBOSE", unset = NA_character_)
+  on.exit({
+    if (is.na(old)) Sys.unsetenv("KORAP_VERBOSE") else Sys.setenv(KORAP_VERBOSE = old)
+  }, add = TRUE)
+
+  # Turn on via env var
+  Sys.setenv(KORAP_VERBOSE = "true")
+  k1 <- KorAPConnection(accessToken = NULL)
+  expect_true(k1@verbose)
+
+  # Explicit argument takes precedence
+  k2 <- KorAPConnection(accessToken = NULL, verbose = FALSE)
+  expect_false(k2@verbose)
+
+  # Turn off via env var
+  Sys.setenv(KORAP_VERBOSE = "false")
+  k3 <- KorAPConnection(accessToken = NULL)
+  expect_false(k3@verbose)
+})
+