feat: add various util methods

Author: streamich

src/util/addClassDecoratorSupport.ts

@@ -0,0 +1,10 @@
+import isStatelessComponent from './isStatelessComponent';
+import wrapInStatefulComponent from './wrapInStatefulComponent';
+
+const addClassDecoratorSupport = (Comp) => {
+  return isStatelessComponent(Comp) ?
+    Comp :
+    wrapInStatefulComponent(Comp);
+};
+
+export default addClassDecoratorSupport;

src/util/isStatelessComponent.ts

@@ -0,0 +1,9 @@
+const isStatelessComponent = (Comp) => {
+  if (typeof Comp !== 'function') {
+    return false;
+  }
+
+  return !Comp.prototype || (Comp instanceof Function);
+};
+
+export default isStatelessComponent;

src/util/mapProps.ts

@@ -0,0 +1,3 @@
+import {h} from '../util';
+
+export const mapProps = (mapper) => (Comp) => (props) => h(Comp, mapper(props));

src/util/renderProp.ts

@@ -0,0 +1,29 @@
+import {isFn} from '../util';
+
+const renderProp = (props, ...args) => {
+  if (process.env.NODE_ENV !== 'production') {
+    if (typeof props !== 'object') {
+      throw new TypeError('renderProp(props, data) first argument must be a prop object.');
+    }
+
+    const {children, render} = props;
+
+    if (isFn(children) && isFn(render)) {
+      console.warn(
+        'Both "render" and "children" are specified for a render-prop component. ' +
+        'Children will be used.'
+      );
+      console.trace();
+    }
+  }
+
+  const {children, render} = props;
+
+  return isFn(children) ?
+    children(...args) :
+    isFn(render) ?
+      render(...args) :
+      (children || null);
+};
+
+export default renderProp;

src/util/wrapInStatefulComponent.ts

@@ -0,0 +1,14 @@
+import {Component} from 'react';
+import {h} from '../util';
+
+const wrapInStatefulComponent = (Comp) => {
+  const Decorated = class Decorated extends Component<any, any> {
+    render () {
+      return h(Comp, this.props);
+    }
+  };
+
+  return Decorated;
+};
+
+export default wrapInStatefulComponent;