Convert from X→ to →Y (X→Y).

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• try online
• cheat sheet
• type-coverage - A CLI tool to check type coverage for typescript code
• dtslint
• TSTools - Tools for developing TypeScript declaration files
• typewiz
• Advanced Static Types in TypeScript

• flowgen

See also:

• Differences between Flowtype and TypeScript

• typescript-to-json-schema
• typescript-json-schema
• typson
• typhen-json-schema

• ts2jsdoc
• ts2jsdoc last commit 16 May 2015

• tsickle
• typescript-closure-compiler
• bolinfest/typescript
• --language_in=ES6_TYPED

• ReasonablyTyped

• js_facade_gen

• ts2kt

• try online
• cheat sheet
• flow-coverage-report - Generate flow coverage reports

• flow-to-typescript
• babel-plugin-flow-to-typescript

See also:

• Utility Types for TypeScript (provide compatibility with Flow's Utility Types)
• Differences between Flowtype and TypeScript

• ReasonablyTyped

• 😢 no options here

Who needs it:

• mapbox-gl-js
• React

• babel-plugin-flow-prepack

• flow2schema
• babel-plugin-flow-to-json

• babel-plugin-flow-react-proptypes

• graphql-code-generator
• gql2ts
• apollo-codegen
• transform.now.sh

See also:

• typed-graphqlify. Build Typed GraphQL Query in TypeScript. Better TypeScript + GraphQL experience
• ts-graphql-plugin

• graphql-code-generator
• gql2flow
• apollo-codegen
• transform.now.sh

• graphql-json-schema

• graphqelm, Comaprison with other packages
• elm-graphql

• graphql_ppx
• graphql-to-reason

• quicktype, 📦 cast
• transform.now.sh
• json-schema-to-typescript-browse

• json-schema-to-flowtype-cli
• flowtypify
• json-schema-to-flow-type

• json-schema-to-graphql-types
• jsonschema-to-graphql

• quicktype, 📦 Json.Decode

• jsonschema-protobuf

• json-schema-table

• OpenAPI

• openapi3-ts

• json-ts

• json-to-flow
• swagger-to-flowtype

• elm-typescript-interop

• flow-jsdoc

• tsd-jsdoc
• typescript-closure-tools
• jsdoc-tsd

• 😢 Allow --declaration with --allowJs
• 😢 TypeScript-flavored JSDoc issues

Who needs it:

• puppeteer

• clutz

• official
• Closure compiler
• TypeScript-flavored JSDoc
• ngdoc
• YUIDoc
• Leafdoc
• jsduck
• esdoc
• autodoc

See also:

• State of documentation.js
• documentation.js: See also

• MakeTypes, 📦 TypeScript Proxies
• quicktype, 📦 cast
• transform.now.sh, 📦 io-ts
• json-ts
• jsontots
• json2ts
• json2dts

• transform.now.sh, 📦 Sarcastic
• json-flow

• graphql-schema-from-json
• json-to-graphql

• transform.now.sh

• json-to-elm, 📦 Json.Decode
• quicktype, 📦 Json.Decode

I suppose this can be used for Scala.js.

• transform.now.sh

• quicktype
• json-to-json-schema

• ppx_deriving_yojson ?

• Get Started with Reason

• genTypescript

• Progress on that prototype for automatically creating Flow APIs for @reasonml
• genFlow

• purescript-ohyes
• purescript-tsd-gen

• purescript-bismuth

Status of Static Typing in ECMAScript

• jstyper
• react-javascript-to-typescript-transform
• dts-gen

• genFlowFilesCommand

• rebind

• react-javascript-to-typescript-transform

• JSXtyper

• codemod-proptypes-to-flow
• proptypes-to-flow-codemod
• codemod-react-proptypes-to-flow
• proptypes-to-flow

• typed-css-modules
• friendly-typed-css-modules

• css-modules-flow-types

• grpc-web
• protobuf.js
• ts-protoc-gen
• protobuf-js-typer

• protobuf2flowtype
• protobuf-js-typer
• protoc-gen-flow

• rejoiner (Java)
• gRPC-to-GraphQL-Adapter

• protoc-gen-jsonschema
• protobuf-jsonschema
• grpc-gateway - reverse-proxy server which translates a RESTful JSON API into gRPC. Optionally emitting API definition for Swagger.

• elm-protobuf

• protoc-gen-persist

• ScalaPB

• thrift-typescript

• schemats

• database-types

• sql-to-graphql
• rdbms-to-graphql
• graphile
• postgraphile

• go-grpc-sql

https://developer.microsoft.com/en-us/microsoft-edge/platform/catalog/ - checkout "Visualization" tab.

• TSJS-lib-generator
• idl2typings

• webidl-to-flow

• typescriptify-golang-structs
• struct2ts

• go2flow

• ts-generator

• type-profile for JavaScript
• MonkeyType for Python
• ruby-type-inference for Ruby

Why do you need Runtime and Static type system together? See this discussion.

• ts-runtime - TypeScript Runtime Type Checks Playground
• io-ts - TypeScript compatible runtime type system for IO validation

• flow-runtime - Flow-compatible runtime type system for JavaScript.
• flow-io - (deprecated) Flow compatible runtime type system for IO validation

• React PropTypes
• tcomb - Type checking and DDD for JavaScript
• hm-def - Runtime type checking for JS with Hindley Milner signatures
• ftor - ftor enables ML-like type-directed, functional programming with Javascript including reasonable debugging
• sanctuary-def - Run-time type system for JavaScript. See also sanctuary#254
• rfx - Self documenting runtime interfaces.
• rtype - Intuitive structural type notation for JavaScript.

See also:

• getdocs - Getdocs is not JSDoc
• ndoc - js port of pdoc, with extentions
• Algebraic Data Types in awesome-fp-js

• testcheck-js
• quickcheck-ts
• Type Test Scripts for TypeScript Testing

• babel-plugin-transform-flow-to-gen
• Randomized Testing in JavaScript Without Lifting a Finger
• jest-runner-flowtype

• jsverify

• elm-check

• qcheck

• purescript-quickcheck

(And not mentioned above)

• purescript
• scala.js
• fable, F# Language Reference

See also:

• List of languages that compile to JS
• Functional Languages that Compile to JavaScript

• Awesome json: format extensions
• The Last JSON Spec
• schemaform