requestMetadata expects exact value instead of matching type

[sathishathpe]

Software versions

• OS: e.g. Mac OSX 10.11.5
• Consumer Pact library: Pact go v2.0.1
• Golang Version: go1.20.5
• Golang environment: GO111MODULE="" GOARCH="amd64" GOBIN="" GOCACHE="/home/dev/.cache/go-build" GOENV="/home/dev/.config/go/env" GOEXE="" GOEXPERIMENT="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="linux" GOINSECURE="" GOMODCACHE="/home/dev/go/pkg/mod" GONOPROXY="github.hpe.com" GONOSUMDB="github.hpe.com" GOOS="linux" GOPATH="/home/dev/go" GOPRIVATE="github.hpe.com" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/local/go" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64" GOVCS="" GOVERSION="go1.20.5" GCCGO="gccgo" GOAMD64="v1" AR="ar" CC="gcc" CXX="g++" CGO_ENABLED="1" GOMOD="/home/dev/ws/pact-go/go.mod" GOWORK="" CGO_CFLAGS="-O2 -g" CGO_CPPFLAGS="" CGO_CXXFLAGS="-O2 -g" CGO_FFLAGS="-O2 -g" CGO_LDFLAGS="-O2 -g" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build1831304596=/tmp/go-build -gno-record-gcc-switches"

Expected behaviour

requestMetadata matching type instead of exact values

Actual behaviour

requestMetadata matching exact value

Steps to reproduce

{
		"pact:proto": "/home/service.proto",
		"pact:proto-service": "Service/Validate",
		"pact:content-type": "application/protobuf",
		"request": {
			"token": "matching(type, 'bj8qnqw9cnalksnd9qwnk1j9cjm')"
		},
		"requestMetadata": {
			"x-b3-traceid": "matching(type, 'foo')"
        },
		"response": {
			"valid": "matching(boolean, true)"
		}
	}

Relevent log files

pact validation failed: [{Request:{Method: Path:Service/Validate Query: Headers:map[] Body:<nil>} Mismatches:[{Actual:0123456789abcdef0123456789abcdef Expected:foo Key: Mismatch:Comparison of metadata key 'x-b3-traceid' failed: Expected 'foo' to be equal to '0123456789abcdef0123456789abcdef' Type:}] Type:}]