Typesafe JSON Schema for ReScript
- Provides ReScript types to work with JSON schema
- Converts rescript-schema into JSON schemas
- Converts JSON schemas to rescript-schema
npm install rescript-json-schema rescript-schema
Then add rescript-json-schema
and rescript-schema
to bs-dependencies
in your rescript.json
:
{
...
+ "bs-dependencies": ["rescript-json-schema", "rescript-schema"]
+ "bsc-flags": ["-open RescriptSchema"],
}
One of the library's main features is the rescript-schema, which provides a way to describe the schema of a value. This schema contains meta information used for parsing, serializing, and generating JSON Schema. When working with the library, you will mostly interact with rescript-schema to define the schema of the values you are working with.
For example, if you have the following schema:
type rating =
| @as("G") GeneralAudiences
| @as("PG") ParentalGuidanceSuggested
| @as("PG13") ParentalStronglyCautioned
| @as("R") Restricted
type film = {
id: float,
title: string,
tags: array<string>,
rating: rating,
deprecatedAgeRestriction: option<int>,
}
let filmSchema = S.object(s => {
id: s.field("Id", S.float),
title: s.field("Title", S.string),
tags: s.fieldOr("Tags", S.array(S.string), []),
rating: s.field(
"Rating",
S.union([
S.literal(GeneralAudiences),
S.literal(ParentalGuidanceSuggested),
S.literal(ParentalStronglyCautioned),
S.literal(Restricted),
]),
),
deprecatedAgeRestriction: s.field("Age", S.option(S.int)->S.deprecate("Use rating instead")),
})
You can use it to generate JSON Schema for the value it describes:
JSONSchema.make(filmSchema)
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"Id": { "type": "number" },
"Title": { "type": "string" },
"Tags": { "items": { "type": "string" }, "type": "array", "default": [] },
"Rating": {
"anyOf": [
{ "type": "string", "const": "G" },
{ "type": "string", "const": "PG" },
{ "type": "string", "const": "PG13" },
{ "type": "string", "const": "R" }
]
},
"Age": {
"type": "integer",
"deprecated": true,
"description": "Use rating instead"
}
},
"additionalProperties": true,
"required": ["Id", "Title", "Rating"]
}