Shopify detect 2.0 theme support

json-theme-check.js

import Shopify from "@shopify/shopify-api";

export const themeCheck = async(ctx, shop, accessToken) => {
  const client = new Shopify.Clients.Rest(shop, accessToken);

  // Get all themes
  const { body: { themes } } = await client.get({
    path: 'themes',
    tries: 3
  });

  // Find the "main" theme
  const mainTheme = themes.find((theme) => theme.role === 'main');
  const { body: { assets } } = await client.get({
    path: `themes/${mainTheme.id}/assets`,
    query: { 'fields': 'key, content_type' },
    tries: 3
  });

  const jsonTemplates = assets
    .filter(file => file.content_type === 'application/json') // only JSON files
    .filter(file => file.key.startsWith('templates/')) // only templates
    .map(file => file.key)
    .map(templateData);

  function templateData(str) {
    let fileParts = last(str.split('/')).split('.');
    fileParts.pop();

    let fileTemplateName = head(fileParts);
    let fileTemplateAlternateName = fileParts[1] || null;

    return {
      template: fileTemplateName,
      alternate: fileTemplateAlternateName
    }
  }

  ctx.body = {
    status: 'success',
    data: {
      jsonTemplates: jsonTemplates
    }
  };

  function head(arr) {
    return arr[0];
  }

  function last(arr) {
    return arr[arr.length - 1];
  }
}