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Type Checking
ScandiPWA uses PropTypes to help verify that the expected props are passed, and catch bugs
PropTypes is a library for React that verifies at runtime if props have the correct type, and if required props are passed.
PropTypes are only used in development builds, which means that production builds will be more efficient - but it also means that you should not rely on PropTypes being present in the production build!
PropTypes are declared as a static field:
component/CategoryPaginationLink/CategoryPaginationLink.component.js (annotated excerpt)
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import { ChildrenType } from 'Type/Common';
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export class CategoryPaginationLink extends PureComponent {
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static propTypes = {
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// component children are treated as props in React
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// by leaving out .isRequired, we make them optional
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children: ChildrenType,
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// we expect the getPage prop to be a function
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// it is required, so this will emit a warning if
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// getPage is not provided
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getPage: PropTypes.func.isRequired,
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// isCurrent expects a boolean
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isCurrent: PropTypes.bool.isRequired,
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// expects a string
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url_path: PropTypes.string.isRequired,
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// expects a number
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pageNumber: PropTypes.number.isRequired
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};
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static defaultProps = {
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// we must provide a default value for every prop that
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// is optionalex
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children: []
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};
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Advanced Types
Sometimes you want to specify that a prop expects something more complex than a number or a string. You can check the official documentation to learn how to use:
instanceOfto expect an instance of a classoneOfto expect an enum-like value that can have one of the specified valuesoneOfTypeto indicate that this prop may have one of the specified typesarrayOforobjectOfto specify that this prop is an array or object where each value has the specified typeshapeorexactto specify that the prop should be an object, as well as what keys and values you expect it to have
For example, you could specify that a prop expecting a payment method should be given an object with two string properties:
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PropTypes.shape({
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code: PropTypes.string,
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title: PropTypes.string
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});
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However, it is likely that this "complex" type would be needed in multiple places in the application. Copy-pasting the same PropType definition would lead to code duplication, and a hard-to-maintain codebase. Instead, we prefer defining these types in the
type directory and exporting them for re-use:type/Checkout.js (excerpt)
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import PropTypes from 'prop-types';
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export const paymentMethodType = PropTypes.shape({
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code: PropTypes.string,
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title: PropTypes.string
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});
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Now, we can use this type definition anywhere we want:
component/CheckoutPayment/CheckoutPayment.component.js (excerpt)
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import { paymentMethodType } from 'Type/Checkout';
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/** @namespace Component/CheckoutPayment/Component */
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export class CheckoutPayment extends PureComponent {
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static propTypes = {
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method: paymentMethodType.isRequired,
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onClick: PropTypes.func.isRequired,
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isSelected: PropTypes.bool
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};
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Last modified 1yr ago
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