fix: Squish 'description' argument

* `ArgumentParser()` will now quietly "squish" its `description` argument
  (which in some cases avoids an error) (#44).
  Thanks Arthur Gilly (@agilly) for bug report.

closes #44

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: argparse
 Type: Package
 Title: Command Line Optional and Positional Argument Parser
-Version: 2.1.7-1
+Version: 2.1.7-2
 Authors@R: c(person("Trevor L", "Davis", role=c("aut", "cre"),
              email="[email protected]",
              comment = c(ORCID = "0000-0001-6341-4639")),

NEWS.md

@@ -6,6 +6,11 @@ argparse 2.1.7
   we now use a quieter default error handler that doesn't output a trailing "Execution halted".
 
 * `add_argument()` now allows "numeric" as an alias for "double" for the `type` argument (#42).
+  Suggestion of @dariober.
+
+* `ArgumentParser()` will now quietly "squish" its `description` argument 
+  (which in some cases avoids an error) (#44).
+  Thanks Arthur Gilly (@agilly) for bug report.
 
 argparse 2.1.6
 ==============

R/argparse.R

@@ -293,6 +293,14 @@ convert_..._to_arguments <- function(mode, ...) { # nolint
         formatter_class <- argument_list[[ii]]
         proposed_arguments[ii] <- sprintf("formatter_class=%s", formatter_class)
     }
+    # Convert whitespace to single space in description
+    if (mode == "ArgumentParser" && any(grepl("description=", proposed_arguments))) {
+        ii <- grep("description=", proposed_arguments)
+        description <- argument_list[[ii]]
+        description <- trimws(gsub("\\s+", " ", description))
+        description <- shQuote(description)
+        proposed_arguments[ii] <- sprintf("description=%s", description)
+    }
     # Set right default prog name if not specified, if possible
     # Do last to not screw up other fixes with prog insertion
     if (mode == "ArgumentParser" && needs_prog(argument_names)) {

tests/testthat/test-argparse.R

@@ -205,6 +205,10 @@ test_that("parse_args() works as expected", {
     expect_equal(args$character, "1")
     expect_equal(args$numeric, 1.0)
 
+    # bug reported by Arthur Gilly
+    parser <- ArgumentParser(description="Description of tool.\nAuthor information.")
+    expect_true(is.list(parser$parse_args()))
+
     # Bug found by Taylor Pospisil
     skip_on_os("windows") # Didn't work on Github Actions Windows
     skip_on_cran() # Once gave an error on win-builder