@alu0101209067/addlogging/src/my-sol-logging-espree.js

Páctice 3 npm module addlogging

#!/usr/bin/env node

const esprima = require('espree');
const estraverse = require('estraverse');
let escodegen = require('escodegen');


/**
 * Function that recive a code like a string and then create a code
 * @param  {string} code
 * @returns {string}
 */
module.exports.addLogging = function(code, pattern = '') {
	let ast = esprima.parse(code, {ecmaVersion: 6, loc : true});
	estraverse.traverse(ast, {
		enter: function(node, parent) {
			if (node.type === 'FunctionDeclaration' ||
					node.type === 'FunctionExpression' 	||
					node.type === 'ArrowFunctionExpression') {
					if (!pattern 
							|| (node.id === null && parent.id.name.match(pattern)) 
							|| node.id 
							&& node.id.name.match(pattern)) 
					{
								addBeforeCode(node);
					}
			}
		}
	});
	return escodegen.generate(ast);
}


/**
 * Function that recive a node add one line of code before code
 * @param  {} node
 * @returns {void}
 */
function addBeforeCode(node) {
	let name = node.id ? node.id.name : '<anonymous function>';
	const params = node.params.map(param =>`\$\{${param.name}\}`);
	let beforeCode = `console.log(\`Entering ${name}(${params}) at line ${node.loc.start.line}\`);`;
	let beforeNodes = esprima.parse(beforeCode, {ecmaVersion: 6}).body; // Is an Array of ASTs
	node.body.body = beforeNodes.concat(node.body.body);
}