lib/addons/src/make-decorator.ts
import { StoryWrapper, LegacyStoryFn, StoryContext } from './types';
type MakeDecoratorResult = (...args: any) => any;
interface MakeDecoratorOptions {
name: string;
parameterName: string;
skipIfNoParametersOrOptions?: boolean;
wrapper: StoryWrapper;
}
export const makeDecorator = ({
name,
parameterName,
wrapper,
skipIfNoParametersOrOptions = false,
}: MakeDecoratorOptions): MakeDecoratorResult => {
const decorator: any = (options: object) => (storyFn: LegacyStoryFn, context: StoryContext) => {
const parameters = context.parameters && context.parameters[parameterName];
if (parameters && parameters.disable) {
return storyFn(context);
}
if (skipIfNoParametersOrOptions && !options && !parameters) {
return storyFn(context);
}
return wrapper(storyFn, context, {
options,
parameters,
});
};
return (...args: any) => {
// Used without options as .addDecorator(decorator)
if (typeof args[0] === 'function') {
return decorator()(...args);
}
return (...innerArgs: any): any => {
// Used as [.]addDecorator(decorator(options))
if (innerArgs.length > 1) {
// Used as [.]addDecorator(decorator(option1, option2))
if (args.length > 1) {
return decorator(args)(...innerArgs);
}
return decorator(...args)(...innerArgs);
}
throw new Error(
`Passing stories directly into ${name}() is not allowed,
instead use addDecorator(${name}) and pass options with the '${parameterName}' parameter`
);
};
};
};