add tests for repr() and extend tests for help msg

test/CMakeLists.txt

@@ -35,6 +35,7 @@ file(GLOB ARGPARSE_TEST_SOURCES
     test_parent_parsers.cpp
     test_parse_args.cpp
     test_positional_arguments.cpp
+    test_repr.cpp
     test_required_arguments.cpp
     test_scan.cpp
     test_value_semantics.cpp

test/test_help.cpp

@@ -1,15 +1,25 @@
-#include <doctest.hpp>
 #include <argparse/argparse.hpp>
+#include <doctest.hpp>
 
 using doctest::test_suite;
 
 TEST_CASE("Users can format help message" * test_suite("help")) {
   argparse::ArgumentParser program("test");
-  program.add_argument("input")
-    .help("positional input");
-  program.add_argument("-c")
-    .help("optional input");
 
+  SUBCASE("Simple arguments") {
+    program.add_argument("input").help("positional input");
+    program.add_argument("-c").help("optional input");
+  }
+  SUBCASE("Default values") {
+    program.add_argument("-a").default_value(42);
+    program.add_argument("-b").default_value(4.4e-7);
+    program.add_argument("-c")
+        .default_value(std::vector<int>{1, 2, 3, 4, 5})
+        .nargs(5);
+    program.add_argument("-d").default_value("I am a string");
+    program.add_argument("-e").default_value(std::optional<float>{});
+    program.add_argument("-f").default_value(false);
+  }
   std::ostringstream s;
   s << program;
   REQUIRE_FALSE(s.str().empty());

test/test_repr.cpp

@@ -0,0 +1,56 @@
+#include <argparse/argparse.hpp>
+#include <doctest.hpp>
+#include <set>
+
+using doctest::test_suite;
+
+TEST_CASE("Test bool representation" * test_suite("repr")) {
+  REQUIRE(argparse::details::repr(true) == "true");
+  REQUIRE(argparse::details::repr(false) == "false");
+}
+
+TEST_CASE_TEMPLATE("Test built-in int types representation" *
+                       test_suite("repr"),
+                   T, char, short, int, long long, unsigned char, unsigned,
+                   unsigned long long) {
+  std::stringstream ss;
+  T v = 42;
+  ss << v;
+  REQUIRE(argparse::details::repr(v) == ss.str());
+}
+
+TEST_CASE_TEMPLATE("Test built-in float types representation" *
+                       test_suite("repr"),
+                   T, float, double, long double) {
+  std::stringstream ss;
+  T v = 0.3333333333;
+  ss << v;
+  REQUIRE(argparse::details::repr(v) == ss.str());
+}
+
+TEST_CASE_TEMPLATE("Test container representation" * test_suite("repr"), T,
+                   std::vector<int>, std::list<int>, std::set<int>) {
+  T empty;
+  T one = {42};
+  T small = {1, 2, 3};
+  T big = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
+
+  REQUIRE(argparse::details::repr(empty) == "{}");
+  REQUIRE(argparse::details::repr(one) == "{42}");
+  REQUIRE(argparse::details::repr(small) == "{1 2 3}");
+  REQUIRE(argparse::details::repr(big) == "{1 2 3 4...15}");
+}
+
+TEST_CASE_TEMPLATE("Test string representation" * test_suite("repr"), T,
+                   char const *, std::string, std::string_view) {
+  T empty = "";
+  T str = "A A A#";
+
+  REQUIRE(argparse::details::repr(empty) == "\"\"");
+  REQUIRE(argparse::details::repr(str) == "\"A A A#\"");
+}
+
+TEST_CASE("Test unknown representation" * test_suite("repr")) {
+  struct TestClass {};
+  REQUIRE(argparse::details::repr(TestClass{}) == "<not representable>");
+}