react-admit-one/dist/utils/getErrorMessage.js

An admit-one ticket for your React components

import getDisplayName from './getDisplayName';
import captureComponentStack from './captureComponentStack';
export default function getErrorMessage(element, firstInstance, usingBoundary) {
    var name = "<" + getDisplayName(element.type) + ">";
    var firstInstanceTrace = firstInstance.stackTrace;
    var secondInstanceTrace = captureComponentStack(element);
    var error = '';
    error += "Warning: the component " + name + " is expected to be mounted ";
    error += "once, but a second attempt to mount this component was made:\n";
    error += secondInstanceTrace + "\n\n";
    error += 'As a result, the component mounted above will not be rendered. ';
    error += "Note that the first instance of " + name + " ";
    error += (firstInstance.element ? 'is already' : 'was') + " mounted";
    error += usingBoundary ? ' within a boundary:\n' : ':\n';
    error += firstInstanceTrace;
    return error;
}