@alu0101240374/addlogging/logging-espree-CLI.js

Espree logging module

#!/usr/bin/env node

const util = require('util');
const fs = require('fs');
var escodegen = require('escodegen');
var espree = require('espree');
var estraverse = require('estraverse');
const program = require('commander');
const { version, description } = require('./package.json');

function addLogging(code, pattern) {
    var ast = espree.parse(code, {ecmaVersion: 6, loc: true});
    let patternRegex = new RegExp(pattern);
    estraverse.traverse(ast, {
        enter: function(node, parent) {
            if ((node.type === 'FunctionDeclaration' ||
                node.type === 'FunctionExpression'  ||
                node.type === 'ArrowFunctionExpression') &&
                (pattern == undefined || node.id == undefined || patternRegex.test(node.id.name))) {
                addBeforeCode(node);
            }
        }
    });
    return escodegen.generate(ast);
}

function addBeforeCode(node) {
    var name = node.id ? node.id.name : '<anonymous function>';
    let parameters = node.params.map(param => `\$\{${param.name}\}`);
    var beforeCode = `console.log(\`Entering ${name}(${parameters}) at line ${node.loc.start.line}\`);`;
    var beforeNodes = espree.parse(beforeCode, { ecmaVersion: 6 }).body;
    node.body.body = beforeNodes.concat(node.body.body);
}

program
  .version(version)
  .description(description)
  .usage('[opciones] <nombreFicheroEntrada>')
  .option('-o, --output <filename>', 'asigna un fichero donde se guardara la salida')
  .option('-p --pattern <patttern>', 'añadira los mensajes a las funcionas que tengan ese pattern');

program.parse(process.argv);
const options = program.opts();

let inputFilename = program.args.shift();

try {
  if (inputFilename) {
    fs.readFile(inputFilename, 'utf8', (err,input) => {
      if (err) throw `Error reading '${inputFilename}': ${err}`;
      const output = (options.pattern) ? addLogging(input, options.pattern) : addLogging(input);
      console.error(`\ninput:\n${input}\n---`);
      if (options.output) {
        fs.writeFile(options.output, output, err => {
          if (err) throw `Cant write to '${options.output}': ${err}`;
          console.log(`Output in file '${options.output}'`);
        })
      }
      else {
        console.error(`output:\n`);
        console.log(output);
      }
    })
  }
}

catch (e) {
  console.error(`Hubieron errores: ${e}`);
}