React.PropTypes array with specific length

Question

Is it possible to use React.PropTypes to enforce length\'s on an array?

Here is a very simple case:

const TWO_NUMBERS = PropTypes.array; // i          


        

Answer 1

A custom function would be the correct approach here.

  const propTypes = {
    TWO_NUMBERS: arrayOfLength.bind(null, 2)
  }

  const arrayOfLength = (expectedLength, props, propName, componentName) => {
    const arrayPropLength = props[propName].length

    if (arrayPropLength !== expectedLength) {
      return new Error(
        `Invalid array length ${arrayPropLength} (expected ${expectedLength}) for prop ${propName} supplied to ${componentName}. Validation failed.`
      )
    }
  }