fix: Send each query parameter value at its own index

[mkieselmann]

Problem

Interaction.Request.queryParam(name:values:) joined all values with a comma and passed the result to pactffi_with_query_parameter_v2 at index 0. An expectation set up with ["foo", "bar"] was therefore recorded as the single value "foo,bar", so a consumer actually sending ?item=foo&item=bar failed to match its own pact:

QueryMismatch: Expected query parameter 'item' with value 'foo,bar' but was 'foo'
QueryMismatch: Expected query parameter 'item' with value '' but was 'bar'
QueryMismatch: Expected query parameter 'item' with 1 value(s) but received 2 value(s)
 Expected: ["foo,bar"]
 Actual: ["foo", "bar"]

This makes repeated query keys impossible to contract-test.

History

The correct behaviour was implemented in 4c01bec already but has been replaced it with values.joined(separator: ",") and a single index-0 call.
A fix has been applied in 5cd4fab, but only for headers not for the query.

withHeader(handle:name:values:interactionPart:) has kept the correct shape ever since and served as the template for this fix.

Change

withQueryParameter now mirrors withHeader and calls the FFI once per value with its offset, so each value is recorded as its own occurrence of the key.

File	Change
Sources/Protocols/PactFFIProviding.swift	withQueryParameter(handle:name:value: String) → values: [String]
Sources/Services/DefaultPactFFIProvider.swift	Indexed values.enumerated() loop; empty array delegates to withQueryParameterWithoutAssociatedValue
Sources/Model/Interaction+Request.swift	Dropped the joined(separator:); documented multi-value and empty-array semantics
Tests/Support/MockPactFFIProvider.swift	Conformance updated to the new signature
Tests/PactBuilderTests.swift	Tests no longer encode the buggy behaviour; adds a regression test

The public API (queryParam(name:values:)) is unchanged — this only corrects how those values reach the FFI.

Behaviour change

An empty values array previously produced ?name= (empty-string value, via [].joined() == ""). It now produces ?name with no associated value, by delegating to the — until now unreachable — withQueryParameterWithoutAssociatedValue, matching the NULL form documented by the FFI. The existing testInteractionWithQueryParameters case ("baz", []) was updated accordingly.

[mkieselmannPDG]

@surpher Thanks for looking into this and merging the PR. Would you mind creating a new Release with that fix so that we can use it in https://github.com/surpher/PactSwift/tree/feat/v2.0.0?

[pepejeria]

Hi @surpher, just checking if it would be possible to create a new release with this. I could then create a PR to have PactSwift consume the new version. Thanks.