Support providing a custom ERB parser class

[joshaber]

What are you trying to accomplish?

Fixes #66

This allows users to specify a custom ERB parser to support non-standard tags. For example, we can use it to comment out <%graphql> tags from https://github.com/github/graphql-client so that Packwerk can parse the rest of the file:

class CustomParser < Packwerk::Parsers::Erb
  def parse_buffer(buffer, file_path:)
    preprocessed_source = buffer.source

    # Comment out <%graphql ... %> tags. They won't contain any object
    # references anyways.
    preprocessed_source = preprocessed_source.gsub(/<%graphql/, "<%#")

    preprocessed_buffer = Parser::Source::Buffer.new(file_path)
    preprocessed_buffer.source = preprocessed_source
    super(preprocessed_buffer, file_path: file_path)
  end
end

Packwerk::Parsers::Factory.instance.erb_parser_class = CustomParser

What approach did you choose and why?

This is similar to how graphql-client handles this same problem for Erubi itself: https://github.com/github/graphql-client/blob/master/lib/graphql/client/erubi_enhancer.rb

What should reviewers focus on?

Is this the appropriate way to set a global configuration value? Should it be set in Configuration instead?

Type of Change

• Bugfix
• New feature
• Non-breaking change (a change that doesn't alter functionality - i.e., code refactor, configs, etc.)

Additional Release Notes

• Breaking change (fix or feature that would cause existing functionality to change)

Users can now specify a custom ERB parser:

Packwerk::Parsers::Factory.instance.erb_parser_class = YourCustomParserClass

Checklist

• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• It is safe to rollback this change.

[joshaber]

I split this to allow subclasses to implement #parse_buffer without concerning themselves with the actual file read.

[joshaber]

CLA signed 👍

[mclark]

👋 Hi folks, is there anything we (@joshaber and I) can do to help move this along? Thanks! 🙇

[exterm]

Sorry folks, we've been a little busy with some internal stuff and the holiday season coming up. We'll get someone to look into this.

[exterm]

As previously the main branch was broken, could you rebase onto the current, fixed one?

[exterm]

Looks good to me.

[exterm]

@tomstuart would you be able to give this a second review?

[tomstuart]

This looks clean, simple & correct to me. Thank you @joshaber!

[joshaber]

Thanks all! ✨