Add new rule 'no-invalid-default-props'

Fixes jsx-eslint#1022

Author: Roy Sutton

docs/rules/no-invalid-default-props.md

@@ -0,0 +1,192 @@
+# Enforce all defaultProps have a corresponding non-required PropType (no-invalid-default-props)
+
+This rule aims to ensure that any `defaultProp` has a non-required `PropType` declaration.
+
+Having `defaultProps` for non-existent `propTypes` is likely the result of errors in refactoring
+or a sign of a missing `propType`. Having a `defaultProp` for a required property similarly
+indicates a possible refactoring problem.
+
+## Rule Details
+
+The following patterns are considered warnings:
+
+```jsx
+function MyStatelessComponent({ foo, bar }) {
+  return <div>{foo}{bar}</div>;
+}
+
+MyStatelessComponent.propTypes = {
+  foo: React.PropTypes.string.isRequired,
+  bar: React.PropTypes.string
+};
+
+MyStatelessComponent.defaultProps = {
+  foo: "foo"
+};
+```
+
+```jsx
+var Greeting = React.createClass({
+  render: function() {
+    return <div>Hello {this.props.foo} {this.props.bar}</div>;
+  },
+
+  propTypes: {
+    foo: React.PropTypes.string,
+    bar: React.PropTypes.string
+  },
+
+  getDefaultProps: function() {
+    return {
+      baz: "baz"
+    };
+  }
+});
+```
+
+```jsx
+class Greeting extends React.Component {
+  render() {
+    return (
+      <h1>Hello, {this.props.foo} {this.props.bar}</h1>
+    );
+  }
+}
+
+Greeting.propTypes = {
+  foo: React.PropTypes.string.isRequired,
+  bar: React.PropTypes.string
+};
+
+Greeting.defaultProps = {
+  foo: "foo"
+};
+```
+
+```jsx
+class Greeting extends React.Component {
+  render() {
+    return (
+      <h1>Hello, {this.props.foo} {this.props.bar}</h1>
+    );
+  }
+
+  static propTypes = {
+    foo: React.PropTypes.string,
+    bar: React.PropTypes.string.isRequired
+  };
+
+  static defaultProps = {
+    baz: "baz"
+  };
+}
+```
+
+```jsx
+type Props = {
+  foo: string,
+  bar?: string
+};
+
+function MyStatelessComponent(props: Props) {
+  return <div>Hello {props.foo} {props.bar}</div>;
+}
+
+MyStatelessComponent.defaultProps = {
+  foo: "foo",
+  bar: "bar"
+}
+```
+
+The following patterns are not considered warnings:
+
+```jsx
+function MyStatelessComponent({ foo, bar }) {
+  return <div>{foo}{bar}</div>;
+}
+
+MyStatelessComponent.propTypes = {
+  foo: React.PropTypes.string,
+  bar: React.PropTypes.string.isRequired
+};
+```
+
+```jsx
+function MyStatelessComponent({ foo, bar }) {
+  return <div>{foo}{bar}</div>;
+}
+
+MyStatelessComponent.propTypes = {
+  foo: React.PropTypes.string.isRequired,
+  bar: React.PropTypes.string
+};
+
+MyStatelessComponent.defaultProps = {
+    bar: 'some default'
+};
+```
+
+```jsx
+type Props = {
+  foo: string,
+  bar?: string
+};
+
+function MyStatelessComponent(props: Props) {
+  return <div>Hello {props.foo} {props.bar}</div>;
+}
+
+MyStatelessComponent.defaultProps = {
+  bar: 'some default'
+};
+```
+
+```js
+function NotAComponent({ foo, bar }) {}
+
+NotAComponent.propTypes = {
+  foo: React.PropTypes.string,
+  bar: React.PropTypes.string.isRequired
+};
+```
+
+## Rule Options
+
+```js
+...
+"no-invalid-default-props": [<enabled>, { "allowRequiredDefaults": <boolean> }]
+...
+```
+
+### `allowRequiredDefaults`
+
+When `true` the rule will ignore `defaultProps` for `isRequired` `propTypes`.
+
+The following patterns are considered okay and do not cause warnings:
+
+```jsx
+function MyStatelessComponent({ foo, bar }) {
+  return <div>{foo}{bar}</div>;
+}
+
+MyStatelessComponent.propTypes = {
+  foo: React.PropTypes.string.isRequired,
+  bar: React.PropTypes.string
+};
+
+MyStatelessComponent.defaultProps = {
+  foo: "foo"
+};
+```
+
+## When Not To Use It
+
+If you don't care about stray `defaultsProps` in your components, you can disable this rule.
+
+## Related rules
+
+- [require-default-props](./require-default-props.md)
+
+# Resources
+- [Official React documentation on defaultProps](https://facebook.github.io/react/docs/typechecking-with-proptypes.html#default-prop-values)
+

index.js

@@ -27,6 +27,7 @@ var allRules = {
   'jsx-no-bind': require('./lib/rules/jsx-no-bind'),
   'jsx-no-undef': require('./lib/rules/jsx-no-undef'),
   'no-unknown-property': require('./lib/rules/no-unknown-property'),
+  'no-invalid-default-props': require('./lib/rules/no-invalid-default-props'),
   'jsx-curly-spacing': require('./lib/rules/jsx-curly-spacing'),
   'jsx-equals-spacing': require('./lib/rules/jsx-equals-spacing'),
   'jsx-sort-props': require('./lib/rules/jsx-sort-props'),