Allow users to simplify entering items when the text and value are th…

…e same.

lib/filters/core-filters.js

@@ -2,14 +2,36 @@
 const { runWhenEnvIsAvailable, external } = require('./api')
 const { addFilter, getFilter } = external
 
-/**
- * Logs an object in the template to the console in the browser.
- * @param  {Any} a any type
- * @return {String} a script tag with a console.log call.
- * @example {{ "hello world" | log }}
- * @example {{ "hello world" | log | safe }}  [for environments with autoescaping turned on]
- */
 runWhenEnvIsAvailable(() => {
   const nunjucksSafe = getFilter('safe')
+
+  /**
+   * Logs an object in the template to the console in the browser.
+   * @param  {Any} a any type
+   * @return {String} a script tag with a console.log call.
+   * @example {{ "hello world" | log }}
+   * @example {{ "hello world" | log | safe }}  [for environments with autoescaping turned on]
+   */
   addFilter('log', a => nunjucksSafe('<script>console.log(' + JSON.stringify(a, null, '\t') + ');</script>'))
+
+  /**
+   * Returns an array of objects for use in a macro that requires a list of items
+   * @param  {String[]} an array of strings.
+   * @return {Object[]} an array of objects with each object containing text and value properties.
+   * @example {{ govukCheckboxes({
+   *             name: "waste",
+   *             fieldset: {
+   *               legend: {
+   *                 text: "Which types of waste do you transport?",
+   *                 isPageHeading: true,
+   *                 classes: "govuk-fieldset__legend--l"
+   *               }
+   *             },
+   *             hint: {
+   *               text: "Select all that apply."
+   *             },
+   *             items: ['Rubble', 'Oil', 'Card'] | formatItems
+   *           }) }}
+   */
+  addFilter('formatItems', (items = []) => Array.isArray(items) ? items.map(item => ({ text: item, value: item })) : [])
 })