Skip to content

rajatasusual/json-schema-2-ts

 
 

Repository files navigation

@rajatasusual/json-schema-2-ts npm mit

Compile json schema to typescript class

Example

Input:

{
  "title": "Example Schema",
  "type": "object",
  "properties": {
    "firstName": {
      "type": "string"
    },
    "lastName": {
      "type": "string"
    },
    "age": {
      "description": "Age in years",
      "type": "integer",
      "minimum": 0
    },
    "hairColor": {
      "enum": ["black", "brown", "blue"],
      "type": "string"
    }
  },
  "additionalProperties": false,
  "required": ["firstName", "lastName"]
}

Output:

export class ExampleSchema {
  firstName: string;
  lastName: string;
  /**
   * Age in years
   */
  age?: number;
  hairColor?: "black" | "brown" | "blue";
}

Installation

# Using Yarn:
yarn add @rajatasusual/json-schema-2-ts

# Or, using NPM:
npm install @rajatasusual/json-schema-2-ts --save

Usage

import { compile, compileFromFile } from 'json-schema-2-ts'

// compile from file
compileFromFile('foo.json')
  .then(ts => fs.writeFileSync('foo.d.ts', ts))

// or, compile a JS object
let mySchema = {
  properties: [...]
}
compile(mySchema, 'MySchema')
  .then(ts => ...)

Options

compileFromFile and compile accept options as their last argument (all keys are optional):

key type default description
additionalProperties boolean true Default value for additionalProperties, when it is not explicitly set
bannerComment string "/* eslint-disable */\n/**\n* This file was automatically generated by @rajatasusual/json-schema-2-ts.\n* DO NOT MODIFY IT BY HAND. Instead, modify the source JSONSchema file,\n* and run @rajatasusual/json-schema-2-ts to regenerate this file.\n*/" Disclaimer comment prepended to the top of each generated file
cwd string process.cwd() Root directory for resolving $refs
declareExternallyReferenced boolean true Declare external schemas referenced via $ref?
enableConstEnums boolean true Prepend enums with const?
format boolean true Format code? Set this to false to improve performance.
ignoreMinAndMaxItems boolean false Ignore maxItems and minItems for array types, preventing tuples being generated.
maxItems number 20 Maximum number of unioned tuples to emit when representing bounded-size array types, before falling back to emitting unbounded arrays. Increase this to improve precision of emitted types, decrease it to improve performance, or set it to -1 to ignore maxItems.
strictIndexSignatures boolean false Append all index signatures with | undefined so that they are strictly typed.
style object { bracketSpacing: false, printWidth: 120, semi: true, singleQuote: false, tabWidth: 2, trailingComma: 'none', useTabs: false } A Prettier configuration
unknownAny boolean true Use unknown instead of any where possible
unreachableDefinitions boolean false Generates code for $defs that aren't referenced by the schema.
$refOptions object {} $RefParser Options, used when resolving $refs

Tests

npm test

Features

  • title => interface
  • Primitive types:
    • array
    • homogeneous array
    • boolean
    • integer
    • number
    • null
    • object
    • string
    • homogeneous enum
    • heterogeneous enum
  • Non/extensible interfaces
  • Custom JSON-schema extensions
  • Nested properties
  • Schema definitions
  • Schema references
  • Local (filesystem) schema references
  • External (network) schema references
  • Add support for running in browser
  • default class name
  • infer unnamed class name from filename
  • deprecated
  • allOf ("intersection")
  • anyOf ("union")
  • oneOf (treated like anyOf)
  • maxItems (eg)
  • minItems (eg)
  • additionalProperties of type
  • patternProperties (partial support)
  • extends
  • required properties on objects (eg)
  • validateRequired (eg)
  • literal objects in enum (eg)
  • referencing schema by id (eg)
  • custom typescript types via tsType

Custom schema properties:

  • tsType: Overrides the type that's generated from the schema. Useful for forcing a type to any or when using non-standard JSON schema extensions (eg).
  • tsEnumNames: Overrides the names used for the elements in an enum. Can also be used to create string enums (eg).

Not expressible in TypeScript:

FAQ

@rajatasusual/json-schema-2-ts is crashing on my giant file. What can I do?

Prettier is known to run slowly on really big files. To skip formatting and improve performance, set the format option to false.

Further Reading

About

Compile JSONSchema to TypeScript type declarations

Resources

License

Stars

Watchers

Forks

Packages

No packages published

Languages

  • TypeScript 100.0%