Allow loading schema from SDL definition file as well as JSON

[Tabby]

If passing a path to a file with a name that ends in ".graphql" or ".graphqls" (matching the filenames used in
graphql-ruby), attempt to load the schema from that file assuming it's a schema definition rather than a JSON schema.

[jesstice]

Is there anything that can be done to help move this PR along? 🙏 This is something our team would benefit from as we have introspection disabled for our graphql server.

[Tabby]

Is there anything that can be done to help move this PR along? 🙏 This is something our team would benefit from as we have introspection disabled for our graphql server.

Knowing it would be helpful for someone else is a pretty good incentive to make time to finish it :)
Tests all pass locally now, and it tests loading a GraphQL schema SDL from both a string and from a file

➜  graphql-client git:(allow-loading-schema-from-sdl-definition) rake test
Run options: --seed 26501

# Running:

........S..SS..............................................................................................................S..............................................

Finished in 1.468751s, 115.7446 runs/s, 437.1061 assertions/s.

170 runs, 642 assertions, 0 failures, 0 errors, 4 skips

You have skipped tests. Run with --verbose for details.

[rmosolgo]

Weird about CI not running... I pulled the branch locally and confirmed that the new tests passed.

(I did have one unrelated failure:

  1) Failure:
TestCollocatedEnforcement#test_exception_backtrace_excludes_enforce_collocated_callers [test/test_collocated_enforcement.rb:68]:
Expected "/Users/rmosolgo/code/graphql-client/test/foo_helper.rb:4:in 'FooHelper#format_person_info'" to include "in `format_person_info'".

I think it's because the backtrace format changed in my version of Ruby.)