Refactor tests (better grouping + cocotb support) (#15)

* initial refactor

* fix cocotb tests

* fix typecheck

* install verilator

tests/body/test_if_body.py

@@ -0,0 +1,85 @@
+from peakrdl_busdecoder.body import IfBody
+class TestIfBody:
+    """Test the IfBody class."""
+
+    def test_simple_if(self):
+        """Test simple if statement."""
+        body = IfBody()
+        with body.cm("condition1") as b:
+            b += "statement1;"
+
+        result = str(body)
+        assert "if (condition1)" in result
+        assert "statement1;" in result
+        assert "end" in result
+
+    def test_if_else(self):
+        """Test if-else statement."""
+        body = IfBody()
+        with body.cm("condition1") as b:
+            b += "if_statement;"
+        with body.cm(None) as b:  # None for else
+            b += "else_statement;"
+
+        result = str(body)
+        assert "if (condition1)" in result
+        assert "if_statement;" in result
+        assert "else" in result
+        assert "else_statement;" in result
+
+    def test_if_elif_else(self):
+        """Test if-elif-else chain."""
+        body = IfBody()
+        with body.cm("condition1") as b:
+            b += "statement1;"
+        with body.cm("condition2") as b:
+            b += "statement2;"
+        with body.cm(None) as b:  # None for else
+            b += "statement3;"
+
+        result = str(body)
+        assert "if (condition1)" in result
+        assert "statement1;" in result
+        assert "else if (condition2)" in result
+        assert "statement2;" in result
+        assert "else" in result
+        assert "statement3;" in result
+
+    def test_multiple_elif(self):
+        """Test multiple elif statements."""
+        body = IfBody()
+        with body.cm("cond1") as b:
+            b += "stmt1;"
+        with body.cm("cond2") as b:
+            b += "stmt2;"
+        with body.cm("cond3") as b:
+            b += "stmt3;"
+
+        result = str(body)
+        assert "if (cond1)" in result
+        assert "else if (cond2)" in result
+        assert "else if (cond3)" in result
+
+    def test_empty_if_branches(self):
+        """Test if statement with empty branches."""
+        body = IfBody()
+        with body.cm("condition"):
+            pass
+
+        result = str(body)
+        assert "if (condition)" in result
+
+    def test_nested_if(self):
+        """Test nested if statements."""
+        outer = IfBody()
+        with outer.cm("outer_cond") as outer_body:
+            inner = IfBody()
+            with inner.cm("inner_cond") as inner_body:
+                inner_body += "nested_statement;"
+            outer_body += inner
+
+        result = str(outer)
+        assert "if (outer_cond)" in result
+        assert "if (inner_cond)" in result
+        assert "nested_statement;" in result
+