.eleventy.js

const pkg = require("./package.json");
const Prism = require("prismjs");
const hasTemplateFormat = require("./src/hasTemplateFormat");
const HighlightPairedShortcode = require("./src/HighlightPairedShortcode");
const LiquidHighlightTag = require("./src/LiquidHighlightTag");
const markdownPrismJs = require("./src/markdownSyntaxHighlightOptions");

module.exports = {
  initArguments: { Prism },
  configFunction: function(eleventyConfig, options = {}) {
    try {
      eleventyConfig.versionCheck(pkg["11ty"].compatibility);
    } catch(e) {
      console.log( `WARN: Eleventy Plugin (${pkg.name}) Compatibility: ${e.message}` );
    }

    options = Object.assign({
      lineSeparator: "\n",
      errorOnInvalidLanguage: false,
      alwaysWrapLineHighlights: false,
      preAttributes: {},
      codeAttributes: {}
    }, options);

    if( hasTemplateFormat(options.templateFormats, "liquid") ) {
      eleventyConfig.addLiquidTag("highlight", (liquidEngine) => {
        // {% highlight js 0 2 %}
        let highlight = new LiquidHighlightTag(liquidEngine);
        return highlight.getObject(options);
      });
    }

    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(" "), options);
      });
    }

    if( hasTemplateFormat(options.templateFormats, "md") ) {
      // ```js/0,2-3
      eleventyConfig.addMarkdownHighlighter(markdownPrismJs(options));
    }

    // we need to add this as many template languages (Vue, WebC) rely on JavaScript functions (not just 11ty.js)
    eleventyConfig.addJavaScriptFunction("highlight", (language, content, highlight1, highlight2) => {
      let highlightLines = [highlight1, highlight2].filter(entry => entry).join(" ");
      let result = HighlightPairedShortcode(content, language, highlightLines, options);
      return result;
    });
  }
};

module.exports.pairedShortcode = HighlightPairedShortcode;