Run test executable; build with unit tests

spec/imbecile_spec.rb

@@ -1,5 +1,6 @@
 require "fileutils"
 
+describe Imbecile do
   def write_grammar(grammar)
     File.write("spec/run/testparser.i", grammar)
   end
@@ -10,11 +11,15 @@ def build_parser
   end
 
   def compile(test_file)
-  result = system(*%w[gdc -o spec/run/testparser spec/run/testparser.d], test_file)
+    result = system(*%w[gdc -funittest -o spec/run/testparser spec/run/testparser.d], test_file)
+    expect(result).to be_truthy
+  end
+
+  def run
+    result = system("spec/run/testparser")
     expect(result).to be_truthy
   end
 
-describe Imbecile do
   before(:each) do
     FileUtils.rm_rf("spec/run")
     FileUtils.mkdir_p("spec/run")
@@ -31,5 +36,6 @@ rule Start [] <<
 EOF
     build_parser
     compile("spec/test_d_lexer.d")
+    run
   end
 end

spec/test_d_lexer.d

@@ -2,3 +2,8 @@ int main()
 {
     return 0;
 }
+
+unittest
+{
+    assert(true);
+}