Using pactffi_with_pact_metadata with duplicate namespace, overwrites existing namespace contents

[YOU54F]

Writing a pact with the following metadata

      pactffi_with_pact_metadata(pact, 'namespace1', 'var_1', 'value_1')
      pactffi_with_pact_metadata(pact, 'namespace1', 'var_2', 'value_2')
      pactffi_with_pact_metadata(pact, 'namespace2', 'var_1', 'value_1')
      pactffi_with_pact_metadata(pact, 'namespace2', 'var_2', 'value_2')
      pactffi_with_pact_metadata(pact, 'pactRust', 'var_1', 'var_1')
      pactffi_with_pact_metadata(pact, 'pactRust', 'var_2', 'var_2')

Results in the following metadata.

  "metadata": {
    "namespace1": {
      "var_2": "value_2"
    },
    "namespace2": {
      "var_2": "value_2"
    },
    "pactRust": {
      "mockserver": "1.2.9",
      "models": "1.2.3",
      "var_2": "var_2"
    },
    "pactSpecification": {
      "version": "3.0.0"
    }

1. namespace1 only has the last entry {"var_2": "value_2"}, missing {"var_1": "value_1"}
2. namespace2 only has the last entry {"var_2": "value_2"}, missing {"var_1": "value_1"}
3. pactRust only has the last entry {"var_2": "value_2"}, missing {"var_1": "value_1"}, existing pactRust entries not removed. (models /mockserver)

Other notes.

• pactSpecification namespace appears to be protected and cannot write to it
• pactRust library versions are not overwritten, so only newly added keys bar the latest are removed, in a single pact execution

Source location for function

pact-reference/rust/pact_ffi/src/mock_server/handles.rs

Lines 1140 to 1152 in f5ddf3d

	pact.with_pact(&|_, inner| {
	let namespace = convert_cstr("namespace", namespace).unwrap_or_default();
	let name = convert_cstr("name", name).unwrap_or_default();
	let value = convert_cstr("value", value).unwrap_or_default();
	if !namespace.is_empty() {
	inner.pact.metadata.insert(namespace.to_string(), json!({ name: value }));
	} else {
	warn!("no namespace provided for metadata {:?} => {:?}. Ignoring", name, value);
	}
	!inner.mock_server_started
	}).unwrap_or(false)
	}

Should we do the following

1. Fix so all added metadata is retained, unless a duplicate call is made which overwrites an existing namespace & key
2. Create a v2 suffixed function that can accept json, rather than a using having to make multiple calls. This pattern is used in the message metadata v2 functions, but I believe this was mainly done to accept matching rules in the integration json format but are not relevant for generic top level Pact file metadata

[JP-Ellis]

I do think the current functions needs to be fixed. Adding to entries to a namespace should result in these two entries being in the namespace. This is a bug which I highly doubt anyone is relying on.

Now for accepting JSON, this really should be added. It can also fallack to handling the string as-is, namely:

1. Try and deserialise the value into a serde_json::Value:
   2. If that succeeds, proceed with the given value in the code as before
   3. If that fails, proceed with the original string as the value

This would be a breaking change to the current behaviour for strings which were handled as strings, but can be deserialized into a JSON value:

Input Str/Current	Fixed
"null"	null
"1"	1
r#"{"foo": "bar"}#	{"foo": "bar"}

Given this function is only for Pact metadata, I do wonder whether incorporating a breaking change into the current function is justified? Or we just be safe and create a _v2 function?

[rholshausen]

I'll update it to return an error if you try to write to pactSpecification or pactRust. Them be mine, and you can't touch.

[YOU54F]

Cheers Ron!