React: checker is not a function

I'm getting this weird warning message in the console for my React app.

Warning: Failed propType: checker is not a function Check the render method of Chart.

I do not have any checker method at all. If I remove my propTypes, the warning is gone. Any ideas?

My react component:

var Chart = React.createClass({
  //...
  propTypes: {
    legend: React.PropTypes.bool,
    max: React.PropTypes.number,
    min: React.PropTypes.number,
    series: React.PropTypes.arrayOf(
      React.PropTypes.shape({
        label: React.PropTypes.string,
        values: React.PropTypes.arrayOf(
          React.PropTypes.arrayOf(
            React.PropTypes.oneOfType(
              React.PropTypes.number,
              React.PropTypes.object // Date
            )
          )
        ),
        colorIndex: React.PropTypes.string
      })
    ).isRequired,
    threshold: React.PropTypes.number,
    type: React.PropTypes.oneOf(['line', 'bar', 'area']),
    units: React.PropTypes.string,
    xAxis: React.PropTypes.arrayOf(React.PropTypes.string)
  },
  render: function() {
    return (<svg>...</svg>);
  }
  //...
});

The payload I send to the Chart component is this one:

var series = [
  {label: 'first', values: [[5,2], [4,3], [3,3], [2,2], [1,1]], colorIndex: "graph-1"},
  {label: 'second', values: [[5,3], [4,2], [3,0], [2,0], [1,0]], colorIndex: "graph-2"}
];

In my case I got this when I used the shape function with a complex object. The solution was to go from:

outerObject: shape({
  firstInnerObject: {
    a: string,
    b: string,
  },
  secondInnerObject: {
    a: string,
    b: number,
  },
}),

To:

outerObject: shape({
  firstInnerObejct: shape({
    a: string,
    b: string,
  }),
  secondInnerObject: shape({
    a: string,
    b: number,
  }),
}),

Very trivial, I know, yet this might be the solution for someone equally inexperienced as I am. ;)

A pull request has been merged to the React repo that provides a better feedback for the developer whenever a mistake like this happens again.

Now, the validation message will look like the following:

Invalid argument supplied to oneOf, expected an instance of array.

https://github.com/facebook/react/pull/3963

This should be part of React 0.14.

Change

React.PropTypes.oneOfType(React.PropTypes.number, React.PropTypes.object)

to

React.PropTypes.oneOfType([React.PropTypes.number, React.PropTypes.object])

(the argument should be an array)

FWIW, I was getting Failed PropType: typeChecker is not a function. I noticed that in my PropTypes.arrayOf() properties, I was passing in an object of PropTypes e.g. PropTypes.arrayOf({})instead of passing in PropTypes.shape() e.g. PropTypes.arrayOf(PropTypes.shape({})

Making this change eliminated the error message.

In my case, I was validating props wrong. I forgot to wrap the profile object into PropTypes shape method.

Mistake

Component.propTypes = {
  viewProfile: PropTypes.shape({
    profile: {     // it is a normal object without a PropTypes shape method
      firstName: PropTypes.string,
      lastName: PropTypes.string,
      profileImage: PropTypes.string,
    },
  }).isRequired,
};

Solution

Component.propTypes = {
  viewProfile: PropTypes.shape({
    profile: PropTypes.shape({
      firstName: PropTypes.string,
      lastName: PropTypes.string,
      profileImage: PropTypes.string,
    }),
  }).isRequired,
};