Add testsuite for argument parser

test/args_test.dart

@@ -0,0 +1,40 @@
+import 'package:libac_dart/argparse/Args.dart';
+import 'package:libac_dart/argparse/Builder.dart';
+import 'package:libac_dart/argparse/CLIHelper.dart';
+import 'package:libac_dart/argparse/types/Bool.dart';
+import 'package:libac_dart/argparse/types/String.dart';
+import 'package:test/expect.dart';
+import 'package:test/scaffolding.dart';
+
+void main() {
+  test("Test parsing a argument", () async {
+    List<String> testArgs = ["--test=12", "--enable", "--put=\"Here\""];
+
+    Arguments defaults = Arguments();
+
+    Arguments parsed = await CLIHelper.parseArgs(testArgs, defaults);
+
+    expect(true, parsed.hasArg("test"));
+    expect(12, parsed.getArg("test")!.getValue() as int);
+    expect(ArgumentType.INTEGER, parsed.getArg("test")!.getType());
+
+    expect(true, parsed.hasArg("enable"));
+    expect(ArgumentType.BOOL, parsed.getArg("enable")!.getType());
+
+    expect("Here", parsed.getArg("put")!.getValue() as String);
+  });
+
+  test("Test printing Usage", () async {
+    Arguments testArgs = ArgumentsBuilder.builder()
+        .withArgument(BoolArgument(
+            name: "use_legacy", description: "Uses legacy settings"))
+        .withArgument(StringArgument(
+            name: "output",
+            value: "./out",
+            description: "Where to put the output files"))
+        .build();
+
+    String usage = CLIHelper.makeArgCLIHelp(testArgs);
+    print("LibAC_Dart\nTestsuite - 1.0\n\n${usage}");
+  });
+}