smartssr/ts/smartssr.classes.smartssr.ts

import * as plugins from './smartssr.plugins';
import * as paths from './smartssr.paths';

import { serializeFunction } from './smartssr.function.serialize';

export interface ISmartSSROptions {
  debug: boolean;
}

/**
 *
 */
export class SmartSSR {
  public options: ISmartSSROptions;

  constructor(optionsArg?: ISmartSSROptions) {
    this.options = {
      ...{
        debug: false,
      },
      ...optionsArg,
    };
  }

  public async renderPage(urlArg: string) {
    const overallTimeMeasurement = new plugins.smarttime.HrtMeasurement();
    overallTimeMeasurement.start();
    const resultDeferred = plugins.smartpromise.defer<string>();
    const browser = new plugins.smartpuppeteer.IncognitoBrowser();
    const renderTimeMeasurement = new plugins.smarttime.HrtMeasurement();
    let renderedPageString: string;
    let screenshotBuffer: Buffer;
    await browser.start();
    try {
      const context = await browser.getNewIncognitoContext();
      const page = await context.newPage();

      // lets protect against left open tabs
      plugins.smartdelay.delayFor(30000).then(async () => {
        try {
          await browser.stop();
        } catch {}
      });

      page.on('console', (msg) => {
        console.log(`${urlArg}: ${msg.text()}`);
      });

      renderTimeMeasurement.start();
      await page.goto(urlArg, {
        waitUntil: 'networkidle2',
        timeout: 30000,
      });

      if (this.options.debug) {
        screenshotBuffer = await page.screenshot({
          encoding: 'binary',
        }) as Buffer;
      }

      await page.$eval('body', serializeFunction);
      const pageContent = await page.content();
      renderedPageString = pageContent;
      resultDeferred.resolve(renderedPageString);
      renderTimeMeasurement.stop();

      // lets clean up async
      await page.close();
      await context.close();
    } catch (e) {
      console.log(e);
    }
    await browser.stop();

    overallTimeMeasurement.stop();
    console.log(
      `Overall it took ${overallTimeMeasurement.milliSeconds} milliseconds to render ${urlArg}`
    );
    console.log(
      `The rendering alone took ${renderTimeMeasurement.milliSeconds} milliseconds for ${urlArg}`
    );

    // debug
    if (this.options.debug) {
      plugins.smartfile.memory.toFsSync(
        renderedPageString,
        plugins.path.join(paths.noGitDir, 'test.html')
      );
      const fs = await import('fs');
      fs.writeFileSync(plugins.path.join(paths.noGitDir, 'test.png'), screenshotBuffer);
    }

    return resultDeferred.promise;
  }
}