.eleventy.js

const Prism = require("prismjs");
const hasTemplateFormat = require("./src/hasTemplateFormat");
const HighlightPairedShortcode = require("./src/HighlightPairedShortcode");
const LiquidHighlightTag = require("./src/LiquidHighlightTag");
const markdownPrismJs = require("./src/markdownSyntaxHighlight");

module.exports = {
  initArguments: { Prism },
  configFunction: function(eleventyConfig, options = {}) {
    // TODO hbs?
    if( hasTemplateFormat(options.templateFormats, "liquid") ) {
      eleventyConfig.addLiquidTag("highlight", (liquidEngine) => {
        // {% highlight js 0 2 %}
        let highlight = new LiquidHighlightTag(liquidEngine);
        return highlight.getObject();
      });
    }

    if( hasTemplateFormat(options.templateFormats, "njk") ) {
      eleventyConfig.addPairedNunjucksShortcode("highlight", (content, args) => {
        // {% highlight "js 0 2-3" %}
        let [language, ...highlightNumbers] = args.split(" ");
        return HighlightPairedShortcode(content, language, highlightNumbers.join(" "));
      });
    }

    if( hasTemplateFormat(options.templateFormats, "md") ) {
      eleventyConfig.addMarkdownHighlighter(markdownPrismJs);
    }
  }
};