@alu0101140469/addlogging/src/logging-sol-daniel.js

Práctica 6 npm Module

#!/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
 * @param  {string} pattern
 * @returns {string}
 */
 let addLogging = function (code, pattern = '') {
    let ast = esprima.parse(code, { ecmaVersion: esprima.latestEcmaVersion, loc: true });
    estraverse.traverse(ast, {
        enter: function(node) {
            if (node.type === 'FunctionDeclaration' ||
                node.type === 'FunctionExpression'  ||
                node.type === 'ArrowFunctionExpression') { 
				if (pattern) { 
					const actualFunctionName = node.id ? node.id.name : undefined;
					if ((actualFunctionName !== undefined) && (actualFunctionName.indexOf(pattern) !== -1)) {
							addBeforeCode(node);
						}
				}
				else {
					addBeforeCode(node);
				}
			}
		}
	});
	return escodegen.generate(ast);
}


/**
 * Function that recive a node add one line of code before code
 * @param  {object} node
 * @returns {void}
 */
function addBeforeCode(node) {
	let name = node.id ? node.id.name : '<anonymous function>';

	let params = ""
	for (let i = 0; i < node.params.length; i++) {
		if (node.params.length - 1 !== i) {
			params += "${" + ` ${node.params[i].name}` + "},";
		}else {
			params += "${" + ` ${node.params[i].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);
}

module.exports = { addLogging };