Function validateExplicitKey

dash/deps/react@16.14.0.js:1795–1825

* Warn if the element doesn't have an explicit key assigned to it. * This element is in an array. The array could grow and shrink or be * reordered. All children that haven't already been validated are required to * have a "key" property assigned to it. Error statuses are cached so a warnin

(element, parentType)

  function validateExplicitKey(element, parentType) {
    if (!element._store || element._store.validated || element.key != null) {
      return;
    }

    element._store.validated = true;
    var currentComponentErrorInfo = getCurrentComponentErrorInfo(parentType);

    if (ownerHasKeyUseWarning[currentComponentErrorInfo]) {
      return;
    }

    ownerHasKeyUseWarning[currentComponentErrorInfo] = true; // Usually the current owner is the offender, but if it accepts children as a
    // property, it may be the creator of the child that's responsible for
    // assigning it a key.

    var childOwner = '';

    if (element && element._owner && element._owner !== ReactCurrentOwner.current) {
      // Give the component that originally created this child.
      childOwner = " It was passed a child from " + getComponentName(element._owner.type) + ".";
    }

    setCurrentlyValidatingElement(element);

    {
      error('Each child in a list should have a unique "key" prop.' + '%s%s See https://fb.me/react-warning-keys for more information.', currentComponentErrorInfo, childOwner);
    }

    setCurrentlyValidatingElement(null);
  }
  /**
   * Ensure that every element either is passed in a static location, in an
   * array with an explicit keys property defined, or in an object literal