first working test (hurray) that checks a mov instruction

test/test_crystal.rb

@@ -1,7 +1,33 @@
-require 'helper'
+require_relative 'helper'
+require "asm/arm/code_generator"
 
-class TestCrystal < MiniTest::Unit::TestCase
-  def test_something_for_real
-    flunk "hey buddy, you should probably rename this file and start testing for real"
+# try  to test that the generation of basic instructions works
+class TestAsm < MiniTest::Test
+  def setup
+    @generator = Asm::Arm::CodeGenerator.new
+  end
+
+  def test_mov
+    m = @generator.instance_eval { mov r0, 5 }.first
+    assert_equal :mov ,  m.opcode
+    binary = @generator.assemble
+    assert_equal 4 , binary.length
+    should = [5,0,160,227]
+    index = 0
+    binary.each_byte do |byte |
+      assert_equal byte , should[index]
+      index += 1
+    end
+  end
+
+  def saved_other
+    @generator.instance_eval do
+      mov r0, 5
+      loop_start = label
+      loop_start.set!
+      subs r0, r0, 1
+      bne loop_start
+      bx lr
+    end
   end
 end