Automatically discover and add missing types in your TypeScript code
# Deprecation Notice

As of 2021, I'm no longer working on TypeWiz. If anyone is interested in forking and developing it, you are more than welcome!

In case you are wondering, nowadays I work on an Wokwi, [an online Arduino & electronics simulation platform](https://wokwi.com).

--

## TypeWiz
Automatically discover and add missing types in your TypeScript code.

<img src="https://github.com/urish/typewiz/blob/master/assets/typewiz.png?raw=true" alt="TypeWiz"/>

[![Build Status](https://travis-ci.org/urish/typewiz.png?branch=master)](https://travis-ci.org/urish/typewiz)
[![Coverage Status](https://coveralls.io/repos/github/urish/typewiz/badge.svg?branch=master)](https://coveralls.io/github/urish/typewiz?branch=master)
[![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square)](https://github.com/prettier/prettier)

## Introduction

TypeWiz monitors your variable types in runtime, and uses this information to add missing type annotations to your
TypeScript code. For instance, given the following source code as input:

```typescript
function add(a, b) {
    return a + b;
}
add(5, 6);
```

TypeWiz will automatically detect the types of `a` and `b` as `number`, and will rewrite to code to read:

```typescript
function add(a: number, b: number) {
    return a + b;
}
add(5, 6);
```

You can learn more about the project in the blog posts:

* [Manual Typing is No Fun: Introducing TypeWiz!](https://medium.com/@urish/manual-typing-is-no-fun-introducing-typewiz-58e3e8813f4c)
* [Diving into the Internals of TypeScript: How I Built TypeWiz](https://medium.com/@urish/diving-into-the-internals-of-typescript-how-i-built-typewiz-d273bbef3565)

## Usage

For front-end code, please have a look at the [TypeWiz WebPack Plugin](packages/typewiz-webpack/README.md).

For node.js code, please check out the [typewiz-node Runner](packages/typewiz-node/README.md).

To use TypeWiz from the command line try the [TypeWiz CLI](packages/typewiz/README.md).

If you are interested in creating your own custom integration, see the [Integration Test](packages/typewiz-core/src/integration.spec.ts) 
for an example how to directly use the TypeWiz API. You can use the API directly by adding this library to your project:

    yarn add -D typewiz-core

or

    npm install --save-dev typewiz-core

## Configuration options

Configuration options can be specified using the `typewiz.json` configuration file. This file is used by `typewiz-node`
and `typewiz-webpack` and can be parsed using the `ConfigurationParser` class in `typewiz-core` for custom integrations.

The `typewiz.json` file has the following format:
```json
{
    "common":{
        "rootDir":".",
        "tsConfig":"tsconfig.json"
    },
    "instrument":{
        "instrumentCallExpressions":true,
        "instrumentImplicitThis":true,
        "skipTwizDeclarations":true
    },
    "applyTypes":{
        "prefix":"TypeWiz |"
    }
}
```

Options:
* `rootDir: string` (default: undefined) - If given, all the file paths in the collected type info will be resolved relative to this directory.
* `tsConfig: string` (default: undefined) - The path to your project's tsconfig.json file. 
    This is required for several other options, like instrumenting implicit this and type inference using static analysis.

* `instrumentCallExpressions: boolean` (default: false) - Try to find even more types by combining static analysis with
    the runtime analysis. TypeWiz will try to use TypeScript's inferred types when determining the type of a function argument. See [#27](https://github.com/urish/typewiz/pull/27) for an example.
* `instrumentImplicitThis: boolean` (default: false) - Find type of `this` in non-class member functions. See [#33](https://github.com/urish/typewiz/issues/33) for discussion.
* `skipTwizDeclarations: boolean` (default: false) - Don't add a declaration of $_$twiz to instrumented files.

* `prefix: string` (default: '') - A prefix to add before each type added by `applyTypes()`. See [#11](https://github.com/urish/typewiz/issues/11).

## License

Copyright (C) 2018, Uri Shaked. Licensed under the MIT license.
