py2wasm/python.py

@@ -219,13 +219,19 @@ class Visitor:
         """
         Visits a UnaryOp node as (part of) an expression
         """
-        del module
+        if isinstance(node.op, ast.UAdd):
-        del wlocals
+            return self.visit_expr(module, wlocals, exp_type, node.operand)
 
-        if not isinstance(node.operand, ast.Constant):
+        if isinstance(node.op, ast.USub):
-            raise NotImplementedError
+            if not isinstance(node.operand, ast.Constant):
+                raise NotImplementedError(node.operand)
 
-        return self.visit_Constant(exp_type, node.operand)
+            if not isinstance(node.operand.value, int):
+                raise NotImplementedError(node.operand.value)
+
+            return self.visit_Constant(exp_type, ast.Constant(-node.operand.value))
+
+        raise NotImplementedError(node.op)
 
     def visit_BinOp(
             self,

tests/integration/test_simple.py

@@ -28,6 +28,32 @@ def testEntry(a: i32) -> i32:
     assert 125 == result.returned_value
     assert [] == result.log_int32_list
 
+@pytest.mark.integration_test
+def test_uadd():
+    code_py = """
+@exported
+def testEntry() -> i32:
+    return +523
+"""
+
+    result = Suite(code_py, 'test_addition').run_code()
+
+    assert 523 == result.returned_value
+    assert [] == result.log_int32_list
+
+@pytest.mark.integration_test
+def test_usub():
+    code_py = """
+@exported
+def testEntry() -> i32:
+    return -19
+"""
+
+    result = Suite(code_py, 'test_addition').run_code()
+
+    assert -19 == result.returned_value
+    assert [] == result.log_int32_list
+
 @pytest.mark.integration_test
 def test_addition():
     code_py = """