How to use the nunjucks.compile function in nunjucks

const { encodeURL, full_url_for } = require('hexo-util');

env.addFilter('uriencode', str => {
  return encodeURI(str);
});

env.addFilter('noControlChars', str => {
  return str.replace(/[\x00-\x1F\x7F]/g, ''); // eslint-disable-line no-control-regex
});

const atomTmplSrc = join(__dirname, '../atom.xml');
const atomTmpl = nunjucks.compile(readFileSync(atomTmplSrc, 'utf8'), env);
const rss2TmplSrc = join(__dirname, '../rss2.xml');
const rss2Tmpl = nunjucks.compile(readFileSync(rss2TmplSrc, 'utf8'), env);
const customTmplSrc = join(__dirname, 'custom.xml');
const customTmlp = nunjucks.compile(readFileSync(customTmplSrc, 'utf8'), env);

const urlConfig = {
  url: 'http://localhost/',
  root: '/'
};

describe('Feed generator', () => {
  const hexo = new Hexo(__dirname, {
    silent: true
  });
  const Post = hexo.model('Post');
  const generator = require('../lib/generator').bind(hexo);

  require('../node_modules/hexo/lib/plugins/helper')(hexo);

  let posts = {};

const { readFileSync } = require('fs');
const cheerio = require('cheerio');
const { encodeURL, full_url_for } = require('hexo-util');

env.addFilter('uriencode', str => {
  return encodeURI(str);
});

env.addFilter('noControlChars', str => {
  return str.replace(/[\x00-\x1F\x7F]/g, ''); // eslint-disable-line no-control-regex
});

const atomTmplSrc = join(__dirname, '../atom.xml');
const atomTmpl = nunjucks.compile(readFileSync(atomTmplSrc, 'utf8'), env);
const rss2TmplSrc = join(__dirname, '../rss2.xml');
const rss2Tmpl = nunjucks.compile(readFileSync(rss2TmplSrc, 'utf8'), env);
const customTmplSrc = join(__dirname, 'custom.xml');
const customTmlp = nunjucks.compile(readFileSync(customTmplSrc, 'utf8'), env);

const urlConfig = {
  url: 'http://localhost/',
  root: '/'
};

describe('Feed generator', () => {
  const hexo = new Hexo(__dirname, {
    silent: true
  });
  const Post = hexo.model('Post');
  const generator = require('../lib/generator').bind(hexo);

  require('../node_modules/hexo/lib/plugins/helper')(hexo);

fs.mkdirSync(this.intermediary_folder, {recursive: true});
		}
		this.output_folder = this.parent.output_folder + this.path_slug;
		if (!fs.existsSync(__dirname + '/' + this.output_folder)) {
			fs.mkdirSync(this.output_folder, {recursive: true});
		}

		console.log('template loaded:');
		console.log(this);

		// read the template itself
		this.template_contents = fs.readFileSync(this.template_file, 'utf8');

		// prepare for templatizing
		this.compiled_file_name = nunjucks.compile(this.file_name);
		this.compiled_template = nunjucks.compile(this.template_contents);
	}

if (!fs.existsSync(__dirname + '/' + this.intermediary_folder)) {
			fs.mkdirSync(this.intermediary_folder, {recursive: true});
		}
		this.output_folder = this.parent.output_folder + this.path_slug;
		if (!fs.existsSync(__dirname + '/' + this.output_folder)) {
			fs.mkdirSync(this.output_folder, {recursive: true});
		}

		console.log('template loaded:');
		console.log(this);

		// read the template itself
		this.template_contents = fs.readFileSync(this.template_file, 'utf8');

		// prepare for templatizing
		this.compiled_file_name = nunjucks.compile(this.file_name);
		this.compiled_template = nunjucks.compile(this.template_contents);
	}

async generateTagsPages(postsMetadata) {
        const tagTemplateNJ = nunjucks.compile(this.theme.getFileContents('index.html'), this.nunjucksEnv);
        const config = this.config;

        await Promise.all([].concat(...Object.entries(postsMetadata).map(([lang, langPosts]) => {
            const postsByTag = {};
            langPosts.forEach((post) => {
                post.categories.forEach((category) => {
                    // TODO replace with kebabCase?
                    const tag = category.toLowerCase().trim().split(' ').join('-');
                    postsByTag[tag] = postsByTag[tag] || [];
                    postsByTag[tag].push(post);
                });
            });

            return Object.entries(postsByTag).map(async ([tag, tagPosts]) => {
                const tagContent = tagTemplateNJ.render({
                    posts: tagPosts,

compile: (src, options) => {
    const template = Nunjucks.compile(src, options.environment)
    return function (context) {
      return template.render(context)
    }
  },
  prepare: (options, next) => {

'use strict';
var nunjucks = require('nunjucks');
var env = new nunjucks.Environment();
var pathFn = require('path');
var fs = require('fs');

env.addFilter('uriencode', function(str) {
	return encodeURI(str);
});

env.addFilter('noControlChars', function(str) {
	return str && str.replace(/[\x00-\x1F\x7F]/g, '');
});

var searchTmplSrc = pathFn.join(__dirname, '../templates/search.xml');
var searchTmpl = nunjucks.compile(fs.readFileSync(searchTmplSrc, 'utf8'), env);

module.exports = function(locals){
  var config = this.config;
  var searchConfig = config.search;
  var template = searchTmpl;
  var searchfield = searchConfig.field;
  var content = searchConfig.content;
  if (content == undefined) content=true;

  var posts, pages;

  if(searchfield.trim() != ''){
    searchfield = searchfield.trim();
    if(searchfield == 'post'){
      posts = locals.posts.sort('-date');
    }else if(searchfield == 'page'){

{# Site icon #}
			{% if icon %}
				
			{% endif %}
		

		
			{# Supports adding arbitrary markup to  start #}
			{{ bodyStart | safe }}

			{# React page content. #}
			<div class="react--loading" id="react">`
.replace(/\t/g, ''))

const TEMPLATE_AFTER_CONTENT = nunjucks.compile
(`</div>

			{% if serverSideRender %}
				{#
					Server-Side Rendering "renderContent" flag.
					It is used to determine whether to call
					"ReactDOM.hydrate()" or "ReactDOM.render()".
				#}

async compile(str, inputPath) {
    let tmpl = NunjucksLib.compile(str, this.njkEnv);
    return async function(data) {
      return new Promise(function(resolve, reject) {
        tmpl.render(data, function(err, res) {
          if (err) {
            reject(err);
          } else {
            resolve(res);
          }
        });
      });
    };
  }
}

compile: (src, options) => {
                        const template = Nunjucks.compile(src, options.environment);
                        return (context) => {
                            return template.render(context);
                        };
                    },
                    prepare: (options, next) => {