WIP: 3.0.0

[phpnode]

(Don't merge this yet)

This is the work in progress rewrite to become compatible with babel6.

Todo:

• [x] type alias support (type foo = string;)
• [x] type parameters support (Array<string>)
• [x] array-tuple support (Array<string, number, boolean>)
• [x] Return type guards
• [x] Argument guards
• [x] Generics support (partial)
• [x] Import / export types
• [x] Variable declarations (var foo: string = "string")
• [x] Static analysis
• [x] Descriptive error messages
• [x] Rest args support
• [x] New docs Slightly better docs
• [x] Figure out plugin ordering
• [x] Type casting
• [x] Assignment checks
• [x] Support ArrayTypeAnnotation
• [x] Support Map<string, number>
• [x] Support Set<string>
• [x] Support function foo (): RegExp { return /a/; }
• [x] Support proper tuples const foo: [string, number] = ["bar", 123]
• [x] Support InterfaceDeclaration and InterfaceExtends
• [x] Support class Foo implements Bar {}
• [x] Support intersection types
• [x] Support TypeofTypeAnnotation
• [x] Support ObjectTypeIndexer
• [ ] Support ObjectTypeCallProperty

Fixes #42 Fixes #39 Fixes #16 Fixes #13 Fixes #10 Fixes #3 Fixes #2

for reference: https://gist.github.com/hzoo/e3a7db9be7a3b0c2094e

Changes

Supports type aliases:

type Foo = string|number;

function demo (input: Foo): string {
  return input + '  world';
}

demo('hello'); // ok
demo(123); // ok
demo(["not", "a", "Foo"]); // fails

Better static type inference

function demo (input: string): Array<string> {
  return makeArray(input); // no return type check required, knows that makeArray is compatible
}

function makeArray (input: string): Array<string> {
  return [input];
}

Type propagation

function demo (input: string): User {
  const user = new User({name: input});
  return user; // No check required, knows that user is the correct type
}

Assignment tracking

let name: string = "bob";

name = "Bob"; // ok
name = makeString(); // ok
name = 123; // SyntaxError, expected string not number

function makeString (): string {
  return "Sally";
}

Type casting

let name: string = "bob";

name = "Bob";
((name: number) = 123);
name = 456;
name = "fish"; // SyntaxError, expected number;

Array type parameters

function demo (input: Array<string>): number {
  return input.length;
}

demo(["a", "b", "c"]); // ok
demo([1, 2, 3]); // TypeError

Shape tracking

type User = {
  name: string;
  email: string;
};

function demo (input: User): string {
  return input.name;
}

demo({}); // TypeError
demo({name: 123, email: "test@test.com"}); // TypeError
demo({name: "test", email: "test@test.com"}); // ok

[phpnode]

@fixplz @motiz88 @STRML this is getting pretty close now, it'd be awesome if you could try it out.

[STRML]

Yeah, will do @phpnode , thanks for the great work!