We’re working on using matchers using the

pactffi_matches_json_value

function, and are seeing some unexpected behavior for some more advanced rules where the check passes even though it shouldn’t… For example, with an

arrayContains

matching rule, no error is returned even though an array with one element that doesn’t satisfy the matching rules is passed to it. Here’s the line in the pactffi log for the check:

2025-03-31T15:16:12.632536Z DEBUG ThreadId(01) pact_matching::json: JSON -> JSON: Comparing '[{"baz":42,"foo":"bar"}]' to '["bla"]' using ArrayContains([(0, MatchingRuleCategory { name: BODY, rules: {DocPath { path_tokens: [Root, Field("baz")], expr: "$.baz" }: RuleList { rules: [Type], rule_logic: And, cascaded: false }} }, {})]) -> Ok(())

We’re using pactffi release 0.4.26 btw, am I missing something here? Thread in Slack Conversation

I'll have to investigate that,

arrayContains

is a tricky matching rule to get right

Sure thing