Target message protocol from upstream Cucumber project

[pjlsergeant]

There are a number of parsing and output protocols in the upstream Cucumber project that if we targeted properly, we could use more of their tooling

[ehuelsmann]

I would argue that the reverse is true: if we part with our own parser (and use theirs), we can use more of their tooling. My proposal is to move to the Gherkin parser in their tree (after it gets fixed using cucumber/common#694).

[ehuelsmann]

I've tried fixing their parser and succeeded. However, quite soon after the working code was contributed, they broke it again.

In order to fix the official parser, I'll need to add a dependency on a protobuf library (https://metacpan.org/pod/Google::ProtocolBuffers::Dynamic). The output they generate isn't the usual binary protobuf output, but JSONLD instead.

I'm not sure I like the dependency on the protobuf library. At least JSON::XS is self-contained. The protobuf library is a binding for an external library, which means an extra hurdle for installation.

[ehuelsmann]

The Perl code in their parser has been upgraded to comply with the latest language definition. Waiting for a release.

[ehuelsmann]

Current state of affairs is that there is no dependency on proto if anymore. Instead, there are jsonschemas which map to ndjson structures. Which allows tapping into the wire protocol much more easily (or rather, at all, imo).

[ehuelsmann]

Oh. And the Perl parser has been released.