Add update_if_exist option to add_parameter

!77+ made `add_parameter` always update the parameter if already
existing, but it may be better to allow to choose depending
on the situation

Author: adanaja

src/e3/aws/troposphere/__init__.py

@@ -118,7 +118,10 @@ def resources(self, stack: Stack) -> list[AWSObject | Construct]:
         # Add the parameter during template creation even if the S3 key may not
         # be known yet. This is useful if creating a stack from code, so that
         # the exported template contains the parameter
-        stack.add_parameter(self.s3_key_parameter)
+        stack.add_parameter(
+            self.s3_key_parameter,
+            update_if_exist=True,
+        )
         # Adding the Output can be useful for Lambda function with versioning.
         # The exported value can be retrieved by the lambda without the need to update
         # the lambda version.
@@ -277,7 +280,7 @@ def add(self, element: AWSObject | Construct | Stack) -> Stack:
                 # Special case to keep track of Assets and generate parameters
                 # for the S3 keys
                 if isinstance(construct, Asset):
-                    self.add_parameter(construct.s3_key_parameter)
+                    self.add_parameter(construct.s3_key_parameter, update_if_exist=True)
                     self.assets[construct.name] = construct
 
                 constructs_to_objects.extend(construct.resources(stack=self))
@@ -296,16 +299,20 @@ def extend(self, elements: Iterable[AWSObject | Construct | Stack]) -> Stack:
 
         return self
 
-    def add_parameter(self, parameter: Parameter | list[Parameter]) -> None:
+    def add_parameter(
+        self, parameter: Parameter | list[Parameter], update_if_exist: bool = False
+    ) -> None:
         """Add parameters to stack template.
 
         :param parameter: parameter to add to the template
+        :param update_if_exist: update the parameter if already exists, avoiding
+            the duplicate key exception
         """
         if not isinstance(parameter, list):
             parameter = [parameter]
 
         for param in parameter:
-            if param.title in self.template.parameters:
+            if update_if_exist and param.title in self.template.parameters:
                 self.template.parameters[param.title] = param
             else:
                 self.template.add_parameter(param)

tests/tests_e3_aws/troposphere/stack/stack_test.py

@@ -59,6 +59,28 @@ def test_add_parameters() -> None:
     assert stack.export()["Parameters"] == expected_template
 
 
+def test_update_parameter() -> None:
+    """Test updating an already existing parameter."""
+    p = Parameter("Parameter", Description="My parameter", Type="String")
+    stack = Stack("test-stack", "this is a test stack")
+    stack.add_parameter(p)
+
+    # This one should fail because of the duplicate key
+    with pytest.raises(match='duplicate key "Parameter" detected'):
+        stack.add_parameter(p)
+
+    # This one should update the parameter
+    p.Description = "Updated parameter"
+    stack.add_parameter(p, update_if_exist=True)
+
+    assert stack.export()["Parameters"] == {
+        "Parameter": {
+            "Description": "Updated parameter",
+            "Type": "String",
+        },
+    }
+
+
 def test_add_outputs() -> None:
     """Test adding outputs to a stack."""
     stack = Stack("test-stack", "this is a test stack")