typescript-json-schema

Generate json-schemas from your Typescript sources.

Features

• Compiles your Typescript program to get complete type information.
• Translates required properties, extends, annotation keywords, property initializers as defaults. You can find examples for these features in the test examples.

Usage

Command line

• Install with npm install typescript-json-schema -g
• Generate schema from a typescript type: typescript-json-schema project/directory/tsconfig.json TYPE

In case no tsconfig.json is available for your project, you can directly specify the .ts files (this in this case we use some built-in compiler presets):

• Generate schema from a typescript type: typescript-json-schema "project/directory/**/*.ts" TYPE

The TYPE can either be a single, fully qualified type or * to generate the schema for all types.

Usage: node typescript-json-schema.js <path-to-typescript-files-or-tsconfig> <type>

Options:
  --refs                Create shared ref definitions.                               [boolean] [default: true]
  --aliasRefs           Create shared ref definitions for the type aliases.          [boolean] [default: false]
  --topRef              Create a top-level ref definition.                           [boolean] [default: false]
  --titles              Creates titles in the output schema.                         [boolean] [default: false]
  --defaultProps        Create default properties definitions.                       [boolean] [default: false]
  --noExtraProps        Disable additional properties in objects by default.         [boolean] [default: false]
  --propOrder           Create property order definitions.                           [boolean] [default: false]
  --required            Create required array for non-optional properties.           [boolean] [default: false]
  --strictNullChecks    Make values non-nullable by default.                         [boolean] [default: false]
  --useTypeOfKeyword    Use `typeOf` keyword (https://goo.gl/DC6sni) for functions.  [boolean] [default: false]
  --out, -o             The output file, defaults to using stdout
  --validationKeywords  Provide additional validation keywords to include            [array]   [default: []]
  --ignoreErrors        Generate even if the program has errors.                     [boolean] [default: false]
  --excludePrivate      Exclude private members from the schema                      [boolean] [default: false]

Programmatic use

import {resolve} from "path";

import * as TJS from "typescript-json-schema";

// optionally pass argument to schema generator
const settings: TJS.PartialArgs = {
    required: true
};

// optionally pass ts compiler options
const compilerOptions: TJS.CompilerOptions = {
    strictNullChecks: true
}

// optionally pass a base path
const basePath = "./my-dir";

const program = TJS.getProgramFromFiles([resolve("my-file.ts")], compilerOptions, basePath);

// We can either get the schema for one file and one type...
const schema = TJS.generateSchema(program, "MyType", settings);


// ... or a generator that lets us incrementally get more schemas

const generator = TJS.buildGenerator(program, settings);

// all symbols
const symbols = generator.getUserSymbols();

// Get symbols for different types from generator.
generator.getSchemaForSymbol("MyType");
generator.getSchemaForSymbol("AnotherType");

Annotations

The schema generator converts annotations to JSON schema properties.

For example

export interface Shape {
    /**
     * The size of the shape.
     *
     * @minimum 0
     * @TJS-type integer
     */
    size: number;
}

will be translated to

{
    "$ref": "#/definitions/Shape",
    "$schema": "http://json-schema.org/draft-07/schema#",
    "definitions": {
        "Shape": {
            "properties": {
                "size": {
                    "description": "The size of the shape.",
                    "minimum": 0,
                    "type": "integer"
                }
            },
            "type": "object"
        }
    }
}

Note that we needed to use @TJS-type instead of just @type because of an issue with the typescript compiler.

Background

Inspired and builds upon Typson, but typescript-json-schema is compatible with more recent Typescript versions. Also, since it uses the Typescript compiler internally, more advanced scenarios are possible.

Debugging

npm run debug -- test/programs/type-alias-single/main.ts --aliasRefs true MyString

And connect via the debugger protocol.