Attribute Macro typegen

#[typegen]

Generates Rust types from GraphQL schema definitions and queries.

Arguments

Positional:

1. String literal with path to the file containing the schema definition. If relative, should be with respect to the project root (wherever Cargo.toml is located). Alternatively, include the schema contents enclosed in square brackets.

Optional keyword:

borrow: Boolean literal indicating whether the generated types should borrow where possible. Defaults to false. When true, deserializing must be done from a string as a opposed to serde_json::Value or a reader.

Trait implementations

By default, will implement PartialEq, Eq, Clone, and Debug for all types. Will implement Copy for enums. For types corresponding to values returned from queries, serde::Deserialize is implemented. For types that would be arguments to a query, serde::Serialize is implemented.

Usage

Must be used with a module. Inside the module, type aliases must be defined for any custom scalars in the schema. To use a query, define a module within the aforementioned module, and annotate it with #[query("path/to/query.graphql")], where the argument is a string literal path to the query document, or the query contents enclosed in square brackets.

Naming

To generate idiomatic Rust code, some renaming of types, enum variants, and fields is performed. Types are renamed with PascalCase, as are enum variants. Fields are renamed with snake_case.

Query restrictions

In order to keep the type generation code relatively simple, there are some restrictions on the queries that are permitted. This may be relaxed in future versions.

• Selection sets on object and interface types must contain either a single fragment spread, or entirely field selections.
• Selection sets on union types must contain either a single fragment spread, or both an unaliased __typename selection and inline fragments for all or a subset of the objects contained in the union.

Example

See top-level documentation of bluejay-typegen for an example.