Function validateProp

static/vuejs/vue.esm.js:1270–1301

(
  key,
  propOptions,
  propsData,
  vm
)

/*  */

function validateProp (
  key,
  propOptions,
  propsData,
  vm
) {
  var prop = propOptions[key];
  var absent = !hasOwn(propsData, key);
  var value = propsData[key];
  // handle boolean props
  if (isType(Boolean, prop.type)) {
    if (absent && !hasOwn(prop, 'default')) {
      value = false;
    } else if (!isType(String, prop.type) && (value === '' || value === hyphenate(key))) {
      value = true;
    }
  }
  // check default value
  if (value === undefined) {
    value = getPropDefaultValue(vm, prop, key);
    // since the default value is a fresh copy,
    // make sure to observe it.
    var prevShouldConvert = observerState.shouldConvert;
    observerState.shouldConvert = true;
    observe(value);
    observerState.shouldConvert = prevShouldConvert;
  }
  if (process.env.NODE_ENV !== 'production') {
    assertProp(prop, key, value, vm, absent);
  }
  return value
}

/**
 * Get the default value of a prop.