Use comments as field description

[chuhlomin]

This PR adds a fields description based on a comments in proto-files (unless they have a custom option BigQueryFieldOptions.Description defined).

[sdotz]

Would love to see this reviewed and merged! We've used this great plugin, plus the code here to generate our BQ schema @ The New York Times. Our protobuf schema is used for generating lots of things in addition to the BQ schema, and so we store all of the field descriptions unobtrusively in comments. We would love to hear about any feedback/improvements as it seems pretty common thing to document .proto fields with comments. Thanks!

[chuhlomin]

@yugui Could you please give a review?

[brucearctor]

Was just looking at writing some similar functionality -- any reason this hasn't gotten reviewed/merged? Other thoughts/approaches that are more sensible? @yugui , @chuhlomin ? What did you wind up using as a solution @sdotz ?

[chuhlomin]

It seems like this repo is not actively maintained.
I ended up forking it: https://github.com/chuhlomin/protoc-gen-bq-schema
And providing Docker image: https://hub.docker.com/repository/docker/chuhlomin/protoc-gen-bq-schema

[sdotz]

I’m using the @chuhlomin fork

[brucearctor]

Awesome, thanks!

[martinroddam]

It's a great addition, but please note that there appears to be an issue with comments in RECORD fields. Raised an issue here.

[mescanne]

Konstantin -- we're looking to start maintaining this repo again. As you've forked it, do you have any interest in continuing to contribute? Thanks.

[mescanne]

I've tested out this change and am happy with it, but would like to update the examples to include descriptions. I'm merging it now and will add that on.