jsGiven/jsGiven

// @flow
export type TagValue = string | string[];

export type Tag = {
  (...values: string[]): Tag,
  +tagDescriptionGenerator: (tag: TagConfiguration, value: string) => string,
} & TagConfiguration;

export type TagConfiguration = {
  +tagName: string,
  +description: string,
  +values: string[],
  +parentTags: Tag[],
  +prependName: boolean,
};

type BuildTagOptions = {
  description: string,
  style: string,
  values: string[],
  parentTags: Tag[],
  prependName: boolean,
  tagDescriptionGenerator: (tag: TagConfiguration, value: string) => string,
};
export function buildTag(
  tagName: string,
  {
    description = '',
    style = '',
    values = [],
    parentTags = [],
    prependName = false,
    tagDescriptionGenerator = ({ description }) => description,
  }: $Shape<BuildTagOptions> = {}
): Tag {
  const tag = (...values: string[]) => {
    const buildTagOptions: BuildTagOptions = {
      description,
      style,
      values,
      parentTags,
      prependName,
      tagDescriptionGenerator,
    };
    return buildTag(tagName, buildTagOptions);
  };
  tag.tagName = tagName;
  tag.description = tag.description;
  tag.values = values;
  tag.parentTags = parentTags;
  tag.prependName = prependName;
  tag.tagDescriptionGenerator = tagDescriptionGenerator;

  return tag;
}