mscgenjs/mscgenjs-cli

import * as puppeteer from "puppeteer";
import { INormalizedOptions, IPuppeteerOptions } from "../types";

function cookEvalFunction(pAST: string, pOptions: INormalizedOptions): string {
  return `const lReplaceMe = document.getElementById('replaceme');
        lReplaceMe.setAttribute("data-language", "json");
        lReplaceMe.setAttribute("data-named-style", "${pOptions.namedStyle}");
        lReplaceMe.setAttribute("data-mirror-entities", ${
          pOptions.mirrorEntities
        });
        lReplaceMe.setAttribute(
            "data-regular-arc-text-vertical-alignment",
            "${pOptions.regularArcTextVerticalAlignment}"
        );
        lReplaceMe.innerHTML = \`${pAST.replace(/\\/g, "\\\\")}\``;
}

function getPuppeteerLaunchOptions(pPuppeteerLaunchOptions: IPuppeteerOptions) {
  return Object.assign(
    {
      headless: true,
    },
    pPuppeteerLaunchOptions || {}
  );
}

async function renderSVG(page: puppeteer.Page) {
  /* the istanbul ignore thing is so istanbul won't instrument code
    that is meant to be run in browser context. If it does,
    you'll get errors like 'Error: Evaluation failed: ReferenceError: cov_'
    - which is chrome (not node) telling us something is foobar
  */
  /* istanbul ignore next */
  return await page.evaluate(() => {
    const lSVGElement = document.getElementById("mscgenjsreplaceme");
    const SVG_DOCTYPE = '<!DOCTYPE svg [<!ENTITY nbsp "&#160;">]>';
    if (lSVGElement) {
      return Promise.resolve(SVG_DOCTYPE + lSVGElement.outerHTML);
    }
    return Promise.reject("Couldn't render the SVG.");
  });
}

async function renderBitmap(
  page: puppeteer.Page,
  pOptions: INormalizedOptions
) {
  await page.setViewport({
    deviceScaleFactor: 2,
    height: 1,
    isMobile: false,
    width: 1,
  });
  return await page.screenshot({
    fullPage: true,
    omitBackground: false,
    type: pOptions.outputType as any,
  });
}

export async function renderWithChromeHeadless(
  pAST: any,
  pOptions: INormalizedOptions
) {
  let browser: puppeteer.Browser = {} as puppeteer.Browser;

  try {
    browser = await puppeteer.launch(
      getPuppeteerLaunchOptions(pOptions.puppeteerOptions)
    );

    const page = await browser.newPage();

    await page.goto(`file:///${__dirname}/template.html`, {
      waitUntil: "networkidle2",
    });

    await page.evaluate(cookEvalFunction(JSON.stringify(pAST), pOptions));

    await page.addScriptTag({
      path: require.resolve("mscgenjs-inpage"),
    });

    await page.waitForSelector("mscgen#replaceme[data-renderedby='mscgen_js']");

    if (pOptions.outputType === "svg") {
      return await renderSVG(page);
    } else {
      return await renderBitmap(page, pOptions);
    }
  } finally {
    if (Boolean(browser) && typeof browser.close === "function") {
      browser.close();
    }
  }
}
/*
    This file is part of mscgenjs-cli.
    mscgenjs-cli is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    mscgen_js is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with mscgenjs-cli.  If not, see <http://www.gnu.org/licenses/>.
*/