Crate json_schema_diff

json-schema-diff

A work-in-progress tool to diff changes between JSON schemas. A lot of JSON schema features are not implemented and therefore ignored, see the issue tracker.

Use this tool as a best-effort to find obviously breaking changes in CI, but not for much more.

This crate is used with draft-07 but even that is work in progress.

Usage via CLI

Install Rust and:

cargo install json-schema-diff

cat schema-old.json schema-new.json
# {"type": "string"}
# {"type": "boolean"}

cargo run --features=build-binary -- \
    schema-old.json \
    schema-new.json
# {"path":"","change":{"TypeRemove":{"removed":"string"}},"is_breaking":true}
# {"path":"","change":{"TypeAdd":{"added":"boolean"}},"is_breaking":false}

Sentry uses this tool in sentry-kafka-schemas to annotate pull requests with breaking changes made to schema definitions. It invokes the CLI tool on the schema from master vs the schema in the PR, and post-processes the output using a Python script for human consumption.

is_breaking is just a suggestion. You may choose to ignore it entirely and instead define which kinds of changes are breaking to you in wrapper scripts.

Usage as library

use json_schema_diff::*;

let lhs = serde_json::json! {{ 
    "type": "string",
}};
let rhs = serde_json::json! {{ 
    "type": "boolean",
}};

assert_eq!(
    json_schema_diff::diff(lhs, rhs).unwrap(),
    vec![
        Change {
            path: "".to_owned(),
            change: ChangeKind::TypeRemove { removed: JsonSchemaType::String }
        },
        Change {
            path: "".to_owned(),
            change: ChangeKind::TypeAdd { added: JsonSchemaType::Boolean }
        }
    ]
);

License

Licensed under Apache 2.0

Structs

Change

An “atomic” change made to the JSON schema in question, going from LHS to RHS.

Enums

ChangeKind

The kind of change + data relevant to the change.

Error

The errors that can happen in this crate.

JsonSchemaType

All primitive types defined in JSON schema.

Range

Range constraints in JSON schema.

Functions

diff

Take two JSON schemas, and compare them.