`juniper_codegen` changelog
===========================

All user visible changes to `juniper_codegen` crate will be documented in this file. This project uses [Semantic Versioning 2.0.0].




## master

### BC Breaks

- `#[graphql_object]` and `#[graphql_subscription]` expansions now preserve defined `impl` blocks "as is" and reuse defined methods in opaque way. ([#971])
- Renamed `rename = "<policy>"` attribute argument to `rename_all = "<policy>"` (following `serde` style). ([#971])
- Redesigned `#[graphql_interface]` macro: ([#1009])
    - Removed support for `dyn` attribute argument (interface values as trait objects).
    - Removed support for `downcast` attribute argument (custom resolution into implementer types).
    - Removed support for `async` trait methods (not required anymore).
    - Removed necessity of writing `impl Trait for Type` blocks (interfaces are implemented just by matching their fields now). ([#113])
    - Forbade default implementations of non-ignored trait methods.
    - Supported coercion of additional `null`able arguments and return sub-typing on implementer.
    - Supported `rename_all = "<policy>"` attribute argument influencing all its fields and their arguments. ([#971])
    - Supported interfaces implementing other interfaces. ([#1028])
- Split `#[derive(GraphQLScalarValue)]` macro into: 
    - `#[derive(GraphQLScalar)]` for implementing GraphQL scalar: ([#1017]) 
        - Supported generic `ScalarValue`.
        - Supported structs with single named field.
        - Supported overriding resolvers with external functions, methods or modules.
        - Supported `specified_by_url` attribute argument. ([#1003], [#1000])
    - `#[derive(ScalarValue)]` for implementing `ScalarValue` trait: ([#1025])
        - Removed `Serialize` implementation (now should be provided explicitly). ([#985])
- Redesigned `#[graphql_scalar]` macro: ([#1014])
    - Changed `from_input_value()` return type from `Option` to `Result`. ([#987]) 
    - Mirrored new `#[derive(GraphQLScalar)]` macro.
    - Supported usage on type aliases in case `#[derive(GraphQLScalar)]` isn't applicable because of [orphan rules].

### Added

- `#[derive(GraphQLInterface)]` macro allowing using structs as GraphQL interfaces. ([#1026])

### Fixed

- All procedural macros expansion inside `macro_rules!`. ([#1054], [#1051])

[#113]: /../../issues/113
[#971]: /../../pull/971
[#985]: /../../pull/985
[#987]: /../../pull/987
[#1000]: /../../issues/1000
[#1003]: /../../pull/1003
[#1009]: /../../pull/1009
[#1014]: /../../pull/1014
[#1017]: /../../pull/1017
[#1025]: /../../pull/1025
[#1026]: /../../pull/1026
[#1028]: /../../pull/1028
[#1051]: /../../issues/1051
[#1054]: /../../pull/1054




[orphan rules]: https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
[Semantic Versioning 2.0.0]: https://semver.org