# graphql-schema-diff
[](https://crates.io/crates/graphql-schema-diff)]
[](https://docs.rs/graphql-schema-diff/)
This crate implements diffing of two GraphQL schemas, returning a list of changes. It powers the changelog feature and operation checks at Grafbase.
## Example
```rust
use graphql_schema_diff::{diff, Change, ChangeKind};
let source = r#"
type Pizza {
id: ID!
name: String!
toppings: [Topping!]!
}
enum Topping {
OLIVES
MUSHROOMS
PINEAPPLE
}
"#;
let target = r#"
type Pizza {
id: ID!
name: PizzaName
toppings: [Topping!]!
}
type PizzaName {
english: String
italian: String!
}
enum Topping {
OLIVES
MUSHROOMS
POTATO
}
"#;
let changes = diff(source, target).unwrap();
assert_eq!(changes,
&[
Change {
path: String::from("Pizza.name"),
kind: ChangeKind::ChangeFieldType
},
Change {
path: String::from("PizzaName"),
kind: ChangeKind::AddObjectType
},
Change {
path: String::from("Topping.PINEAPPLE"),
kind: ChangeKind::RemoveEnumValue
},
Change {
path: String::from("Topping.POTATO"),
kind: ChangeKind::AddEnumValue
}
]);
```
## Cargo features
- `serde`: `Serialize` and `Deserialize` impls for `Change` (default: on).