canonicalize.markdown

Canonicalize

jsonschema canonicalize <schema.json>

JSON Schema is an extremely expressive schema language. As such, schema authors can express the same constraints in a variety of ways, making the process of statically analyzing schemas complex. This command attempts to tackle the problem by transforming a given JSON Schema into a simpler (but more verbose) normalized form referred to as canonical.

Refer to Juan Cruz Viotti's dissertation on JSON BinPack for how JSON Schema canonicalization was originally defined.

Examples

For example, consider the following simple schema:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "foo": { "type": "string" }
  }
}

The canonicalization process will result in something like this:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "anyOf": [
    {
      "enum": [
        null
      ]
    },
    {
      "enum": [
        false,
        true
      ]
    },
    {
      "type": "object",
      "minProperties": 0,
      "properties": {
        "foo": {
          "type": "string",
          "minLength": 0
        }
      }
    },
    {
      "type": "array",
      "minItems": 0
    },
    {
      "type": "string",
      "minLength": 0
    },
    {
      "type": "number",
      "multipleOf": 1
    },
    {
      "type": "integer",
      "multipleOf": 1
    }
  ]
}

Canonicalize a JSON Schema

jsonschema canonicalize path/to/my/schema.json