jeffmo

[version]
0.18.1

jeffmo

// @flow

import React from "React";

class JDiv extends React.Component {
  props: {
    id: string
  };
}

jeffmo

// @flow

import React from "React";

class JDiv extends React.Component {
  props: {
    id: string
  };

  render() {

jeffmo

// @flow

import React from "React";

class JDiv extends React.Component {
  props: {
    id: string
  };
}

jeffmo

// @flow

class Foo {
  prop1 = 'asdf';
  prop2: number;

  constructor() {
    this.prop2 = this.prop1;
  }
}

jeffmo

// @flow

class Foo {
  prop1: string = 'asdf';

  constructor() {
    this.prop1 = 42;
  }
}

jeffmo

[options]
esproposal.class_instance_fields=enable

jeffmo

/* @flow */

function foo() {
  arguments;
}

jeffmo

###v0.18.0

Likely to cause new Flow errors:

• Flow is now stricter (and more consistent) about how null works when used as an initialization value for object properties that are mutated later. So let o = {prop: null}; o.prop = 42; is now an error and requires that null be annotated: let o = {prop: (null: ?number)};.
• The return type of RegExp.prototype.match() is now properly annotated to return a nullable.

New Features:

• We now take advantage of the guarantee that const variables are read-only when doing refinements. This means that refinements of const variables now have much fewer caveats than refinements of lets or vars!

jeffmo

###v0.18.0

Likely to cause new Flow errors:

• Flow is now stricter (and more consistent) about how null works when used as an initialization value for object properties that are mutated later. So let o = {prop: null}; o.prop = 42; is now an error and requires that null be annotated: let o = {prop: (null: ?number)};.
• The return type of RegExp.prototype.match() is now properly annotated to return a nullable.

New Features:

• We now take advantage of the guarantee that const variables are read-only when doing refinements. This means that refinements of const variables now have much fewer caveats than refinements of lets or vars!