realm-js/examples/ReactExample/tests/util.js

60 lines
1.5 KiB
JavaScript

/* Copyright 2016 Realm Inc - All Rights Reserved
* Proprietary and Confidential
*/
'use strict';
import React from 'react-native';
const rootComponentPromise = new Promise((resolve) => {
// Require internal module here so the promise is rejected if there is an error.
let Mount = require('react-native/Libraries/ReactNative/ReactNativeMount');
let renderComponent = Mount.renderComponent;
Mount.renderComponent = function() {
let component = renderComponent.apply(this, arguments);
resolve(component);
return component;
};
});
export function getRootComponent() {
return rootComponentPromise;
}
export function assertChildExists(component, name) {
if (!findChildComponent(component, name)) {
throw new Error(name + ' not rendered');
}
}
export function findChildComponent(component, name) {
for (let child of traverseChildren(component)) {
if (child.type.name == name) {
return child;
}
}
return null;
}
export function* traverseChildren(component) {
let props = component.props;
// The hacky TopLevelWrapper has its props set to the root element.
if (props.props) {
props = props.props;
}
let children = props.children;
if (!children) {
return;
}
// ReactNative is missing React.Children.toArray()
for (let child of React.Children.map(children, (x) => x)) {
yield child;
yield* traverseChildren(child);
}
}