mutators/removeObjPropsMutator.js

const walk = require('babylon-walk')
const debug = require('debug')('mutode:removeObjPropsMutator')
const mutantRunner = require('../mutantRunner')
const lineDiff = require('../util/lineDiff')
/**
 * @description Mutates objects by removing single properties
 * @function removeObjPropsMutator
 * @memberOf module:Mutators
 */
module.exports = async function removeObjPropsMutator ({mutodeInstance, filePath, lines, queue, ast}) {
  debug('Running remove object properties mutator on %s', filePath)
  walk.simple(ast, {
    ObjectProperty (node) {
      const propertyName = node.key.name
      let contentToWrite = ''
      let log = ''
      if (node.loc.start.line !== node.loc.end.line) {
        const line = node.loc.start.line
        const mutantId = ++mutodeInstance.mutants
        log = `MUTANT ${mutantId}:\tROPM Lines ${node.loc.start.line}-${node.loc.end.line}: Commented property ${propertyName}`
        debug(log)
        mutodeInstance.mutantLog(log)
        const linesCopy = lines.slice()
        for (let i = line - 1; i < node.loc.end.line; i++) {
          linesCopy[i] = `// ${linesCopy[i]}`
        }
        contentToWrite = linesCopy.join('\n')
      } else {
        const line = node.loc.start.line
        const lineContent = lines[line - 1]
        let trimmed = false
        let start = lineContent.substr(0, node.loc.start.column)
        if (start.trim().endsWith(',')) {
          start = start.substr(0, start.lastIndexOf(','))
          trimmed = true
        }
        let end = lineContent.substr(node.loc.end.column)
        if (!trimmed && end.startsWith(',')) end = end.substr(1).trim()
        const mutantLineContent = start + end
        const mutantId = ++mutodeInstance.mutants
        const diff = lineDiff(lineContent, mutantLineContent)
        log = `MUTANT ${mutantId}:\tROPM Line ${line}:\t${diff}`
        debug(log)
        mutodeInstance.mutantLog(`MUTANT ${mutantId}:\tROPM ${filePath} Line ${line}:\t\`${lineContent.trim()}\` > \`${mutantLineContent.trim()}'\``)
        const linesCopy = lines.slice()
        linesCopy[line - 1] = mutantLineContent
        contentToWrite = linesCopy.join('\n')
      }
      queue.push(mutantRunner({mutodeInstance, filePath, contentToWrite, log}))
    }
  })
}