npm install -g json-ts

Automatically generate Typescript Definition files or Flow types from JSON input.

Use it via the API, CLI, or Website

How does json-ts stack up against the competition?

|Feature |json-ts (this library) |json-to-ts |json2ts | |---|---|---|---| |simple literal types (number, string etc) |YES |YES |YES | |array type, all elements of same kind |YES |YES |YES | |merge multiple json files|YES (cli, v1.6 & above) |NO |NO | |optional members | YES | YES | NO | |array union types | YES |YES |NO | |correct handling of top-level values (strings, arrays, arrays of objects numbers etc) |YES |NO |NO | |recursive data structures (see here) |YES |NO |NO | |nested type literals (to account for invalid interface names) |YES |YES |NO | |output @flow types |YES |NO |NO | |Website |YES |YES |YES | |CLI |YES |NO |NO | |API |YES |YES |NO |

Quick-start

# install
npm install -g json-ts

# run against a single JSON file
json-ts dir/myfile.json

# run against multiple single JSON files (interfaces will be merged)
json-ts api/resp1.json api/resp2.json

Usage (CLI)

Note: only stdin (which requires the --stdin flag) & filepaths are supported right now. Later I will add support for Windows, reading data from network requests etc.

## piping via stdin
curl https://jsonplaceholder.typicode.com/posts/1 | json-ts --stdin

## reading single json file from disk
json-ts my-file.json

## reading multiple json files from disk
json-ts my-file.json my-other-file.json

... produces the following:

interface IRootObject {
  userId: number;
  id: number;
  title: string;
  body: string;
}

Usage (API)

npm install json-ts --save-dev

const { json2ts } = require('json-ts');
const json = `
{
    "name": "Shane"
}
`;
console.log(json2ts(json))

... produces the following:

interface IRootObject {
  name: string;
}

For more examples, see the Tests

Options

• namespace: string - if provided, interfaces will be wrapped in a namespace (see below)

  # usage
  json-ts <filename> --namespace <namespace_name> 
     
  # example
  json-ts data/my-file.json --namespace API

• flow: boolean - output types in Flow format.

  # usage
  json-ts <filename> --flow 
     
  # example
  json-ts data/my-file.json --flow

• prefix: string - override the I prefix on interface names

  # usage
  json-ts <filename> --prefix <prefix_string> 
     
  # example (remove prefix)
  json-ts data/my-file.json --prefix ""

• rootName: string - override the RootObject name of the top-level interface

  # usage
  json-ts <filename> --rootName <rootname_string> 
     
  # example
  json-ts data/my-file.json --rootName "Product"

TODO:

options

• [x] Allow choice of I prefix on interface names
• [x] Allow naming of RootObject
• [ ] Allow choice of spaces/tabs

Core

• [x] support array types
• [x] support boolean types
• [x] support null types
• [x] output types for Flow via --flow
• [x] PascalCase as default for all interface names
• [x] de-dupe interfaces (it's dumb atm, POC)
• [x] de-dupe interfaces where propname differs, but members are the same
• [x] merge interfaces by creating union types for members
• [x] union types for array that contain mixed literal types: nums: [1, "2"] -> nums: number|string[] (already works for complex objects)
• [x] quoted member names when needed
• [x] handle invalid name for interface
• [x] support type alias declarations
• [x] Use Typescript factory methods/printer for output
• [x] Allow wrapping in namespace: eg:

      declare namespace Projects {
          export interface ILoc {
             lat: number;
             lng: number;
          }
          ...
      }

CLI

• [x] CLI tool to accept stdin (with --stdin flag)
• [x] CLI tool to accept json file as input
• [ ] CLI tool to accept URL as input (for validating against remote API)
• [ ] configurable output (filename/stdout etc)