ReScript JSON Schema 📄

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

Install

1npm install rescript-json-schema rescript-schema

Then add rescript-json-schema and rescript-schema to bs-dependencies in your rescript.json:

1{
2  ...
3+ "bs-dependencies": ["rescript-json-schema", "rescript-schema"]
4+ "bsc-flags": ["-open RescriptSchema"],
5}

Create JSON schemas with type safety

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:

1type rating =
2  | @as("G") GeneralAudiences
3  | @as("PG") ParentalGuidanceSuggested
4  | @as("PG13") ParentalStronglyCautioned
5  | @as("R") Restricted
6type film = {
7  id: float,
8  title: string,
9  tags: array<string>,
10  rating: rating,
11  deprecatedAgeRestriction: option<int>,
12}
13
14let filmSchema = S.object(s => {
15  id: s.field("Id", S.float),
16  title: s.field("Title", S.string),
17  tags: s.fieldOr("Tags", S.array(S.string), []),
18  rating: s.field(
19    "Rating",
20    S.union([
21      S.literal(GeneralAudiences),
22      S.literal(ParentalGuidanceSuggested),
23      S.literal(ParentalStronglyCautioned),
24      S.literal(Restricted),
25    ]),
26  ),
27  deprecatedAgeRestriction: s.field("Age", S.option(S.int)->S.deprecate("Use rating instead")),
28})

You can use it to generate JSON Schema for the value it describes:

1JSONSchema.make(filmSchema)

1{
2  "$schema": "http://json-schema.org/draft-07/schema#",
3  "type": "object",
4  "properties": {
5    "Id": { "type": "number" },
6    "Title": { "type": "string" },
7    "Tags": { "items": { "type": "string" }, "type": "array", "default": [] },
8    "Rating": {
9      "anyOf": [
10        { "type": "string", "const": "G" },
11        { "type": "string", "const": "PG" },
12        { "type": "string", "const": "PG13" },
13        { "type": "string", "const": "R" }
14      ]
15    },
16    "Age": {
17      "type": "integer",
18      "deprecated": true,
19      "description": "Use rating instead"
20    }
21  },
22  "additionalProperties": true,
23  "required": ["Id", "Title", "Rating"]
24}

Create rescript-schema from JSON schema

Online

Just paste your JSON schemas here!