Made instruction representation tests more independant

tests/test_instruction.py

@@ -30,14 +30,27 @@ def instr():
     )
 
 
-class TestRepr:
-    """Tests for the ``__repr__`` method."""
+# ------------------------------------------------------------------------------
 
-    def test_default_repr_instruction_only(self, instr: _Instruction):
+
+def test_default_repr_instruction_only(instr: _Instruction):
     """Default representation returns action followed by ``()``."""
     rv = instr.repr_instruction_only()
     assert rv == _INSTR_REPR
 
+
+class TestRepr:
+    """Tests for the ``__repr__`` method."""
+
+    @pytest.fixture
+    def instr(self):
+        """Create a mock instruction suitable for testing."""
+        instr = _Instruction(
+            mock.MagicMock(), mock.MagicMock(), mock.MagicMock(), _ACTION_NAME
+        )
+        instr.repr_instruction_only = mock.MagicMock(return_value=_INSTR_REPR)
+        return instr
+
     def test_repr_no_flow(self, instr: _Instruction):
         """``repr()`` returns default representation if there is no flow \
                 control or variables."""