WIP: Refactor package

[dotansimha]

Progress: 99.999%

The goals are:

• Move codegen core to a package and don't use fs
• Move generators to separate package
• Refactor directories structure and use Lerna to manage package's dependencies
• Refactor GraphQL Schema template context builder and object
• Handle fields and types in a better way (related to Mutation with only a string return. #96 and input types are not emitted (typescript, noSchema===true) #84) - my idea is to use expose the schema template context the same way GraphQL treat it's types (separate arrays for enum, type, input, union, interface, scalar)
• Treat Query and Mutation just like any other type
• Fix CI
• Refactor operations builder with flatten feature
• Reimplement typescript-single-file
• Reimplement imports builder for multiple files
• Reimplement typescript-multi-file
• Move and refactor CLI util to a separate package (use fs only here)
• Add support for input/output of a whole project (to generate apps)
• Fix lerna dependencies
• Add support for magic comments to easier integration in existing project (/*gqlgen {{#each types }} */
• Move generators to separate packages with compilation package
• Add support for directives (Add support for directives applied on IDL & Schema graphql/graphql-js#746)
• Update README

After merging to master:

• Reimplement flow-single-file
• Reimplement swift-single-file
• 100% code coverage for core & compiler packages
• Blog post

Ideas:

• Consider implementing the flatten types map in a better way - maybe just add a reference inside the template context to the actual type along the type name.

[dotansimha]

@DxCx @zephraph @eitanfr @davidyaha any thoughts?

[zephraph]

Whew... this is a huge change. Okay, I'll comment as I can go through it...

[dotansimha]

@zephraph my goal is to simplify the schema handler first.
I am almost done, and you can find it here: https://github.com/dotansimha/graphql-code-generator/blob/refactor/all/packages/graphql-codegen-core/src/schema/schema-to-template-context.ts
Also, I changed the schema template context object to be: https://github.com/dotansimha/graphql-code-generator/blob/refactor/all/packages/graphql-codegen-core/src/types.ts#L59-L72

This is much simpler implementation for the Schema handling, the difference is that I'm creating an array for each GraphQL base type (scalar/enum/type/input...), instead of a single array for all of them together.

I also separated it to 3 packages:

• core (GraphQLSchema and operations string => template context object)
• generators (combines template and template context, also in charge of converting primitives to language primitives, eg. String => string and Int to number in case of TS)
• cli (Find, read, introspect and execute core with generators package)

[zephraph]

It might be a good idea to generate a copy of dev-test from master (on all supported variations) and have a test just for comparing final generated outputs.