example/dist/bundle.js
function checkPropTypes(typeSpecs, values, location, componentName, getStack) {
  if (true) {
    for (var typeSpecName in typeSpecs) {
      if (typeSpecs.hasOwnProperty(typeSpecName)) {
        var error;
        // Prop type validation may throw. In case they do, we don't want to
        // fail the render phase where it didn't fail before. So we log it.
        // After these have been cleaned up, we'll let them throw.
        try {
          // This is intentionally an invariant that gets caught. It's the same
          // behavior as without this statement except with a better message.
          if (typeof typeSpecs[typeSpecName] !== 'function') {
            var err = Error(
              (componentName || 'React class') + ': ' + location + ' type `' + typeSpecName + '` is invalid; ' +
              'it must be a function, usually from the `prop-types` package, but received `' + typeof typeSpecs[typeSpecName] + '`.'
            );
            err.name = 'Invariant Violation';
            throw err;
          }
          error = typeSpecs[typeSpecName](values, typeSpecName, componentName, location, null, ReactPropTypesSecret);
        } catch (ex) {
          error = ex;
        }
        if (error && !(error instanceof Error)) {
          printWarning(
            (componentName || 'React class') + ': type specification of ' +
            location + ' `' + typeSpecName + '` is invalid; the type checker ' +
            'function must return `null` or an `Error` but returned a ' + typeof error + '. ' +
            'You may have forgotten to pass an argument to the type checker ' +
            'creator (arrayOf, instanceOf, objectOf, oneOf, oneOfType, and ' +
            'shape all require an argument).'
          )

        }
        if (error instanceof Error && !(error.message in loggedTypeFailures)) {
          // Only monitor this failure once because there tends to be a lot of the
          // same error.
          loggedTypeFailures[error.message] = true;

          var stack = getStack ? getStack() : '';

          printWarning(
            'Failed ' + location + ' type: ' + error.message + (stack != null ? stack : '')
          );
        }
      }
    }
  }
}
function checkPropTypes(typeSpecs, values, location, componentName, getStack) {
  if (true) {
    for (var typeSpecName in typeSpecs) {
      if (typeSpecs.hasOwnProperty(typeSpecName)) {
        var error;
        // Prop type validation may throw. In case they do, we don't want to
        // fail the render phase where it didn't fail before. So we log it.
        // After these have been cleaned up, we'll let them throw.
        try {
          // This is intentionally an invariant that gets caught. It's the same
          // behavior as without this statement except with a better message.
          if (typeof typeSpecs[typeSpecName] !== 'function') {
            var err = Error(
              (componentName || 'React class') + ': ' + location + ' type `' + typeSpecName + '` is invalid; ' +
              'it must be a function, usually from the `prop-types` package, but received `' + typeof typeSpecs[typeSpecName] + '`.'
            );
            err.name = 'Invariant Violation';
            throw err;
          }
          error = typeSpecs[typeSpecName](values, typeSpecName, componentName, location, null, ReactPropTypesSecret);
        } catch (ex) {
          error = ex;
        }
        if (error && !(error instanceof Error)) {
          printWarning(
            (componentName || 'React class') + ': type specification of ' +
            location + ' `' + typeSpecName + '` is invalid; the type checker ' +
            'function must return `null` or an `Error` but returned a ' + typeof error + '. ' +
            'You may have forgotten to pass an argument to the type checker ' +
            'creator (arrayOf, instanceOf, objectOf, oneOf, oneOfType, and ' +
            'shape all require an argument).'
          )

        }
        if (error instanceof Error && !(error.message in loggedTypeFailures)) {
          // Only monitor this failure once because there tends to be a lot of the
          // same error.
          loggedTypeFailures[error.message] = true;

          var stack = getStack ? getStack() : '';

          printWarning(
            'Failed ' + location + ' type: ' + error.message + (stack != null ? stack : '')
          );
        }
      }
    }
  }
}
Assert that the values match with the type specs.
Error messages are memorized and will only be shown once.

@param {object} typeSpecs Map of name to a ReactPropType
@param {object} values Runtime values that need to be type-checked
@param {string} location e.g. "prop", "context", "child context"
@param {string} componentName Name of the component for error messages.
@param {?Function} getStack Returns the component stack.
@private