Cannot run `detectInFiles()` several times in a row

Describe the bug When running detectInFiles() several times in a row, the second run re-uses state from the previous run. This leads to files reporting duplication “on themselves” (i.e. duplicationA and duplicationB are the same line in the same file, for all lines in all files).

To Reproduce

example.js:

module.exports = {}

bug.js:

'use strict'

const { JSCPD } = require('jscpd')
const instance = new JSCPD({ minTokens: 1, minLines: 1 })
const detect = async function() {
  const clones = await instance.detectInFiles(['example.js'])
  console.log(clones)
}
detect().then(detect)

Output:

┌────────────┬────────────────┬─────────────┬──────────────┬──────────────────┬────┐
│ Format     │ Files analyzed │ Total lines │ Clones found │ Duplicated lines │ %  │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────┤
│ javascript │ 1              │ 1           │ 0            │ 0                │ 0% │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────┤
│ Total:     │ 1              │ 1           │ 0            │ 0                │ 0% │
└────────────┴────────────────┴─────────────┴──────────────┴──────────────────┴────┘
Execution Time: 91.967ms
[]
┌────────────┬────────────────┬─────────────┬──────────────┬──────────────────┬────┐
│ Format     │ Files analyzed │ Total lines │ Clones found │ Duplicated lines │ %  │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────┤
│ javascript │ 2              │ 2           │ 0            │ 0                │ 0% │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────┤
│ Total:     │ 2              │ 2           │ 0            │ 0                │ 0% │
└────────────┴────────────────┴─────────────┴──────────────┴──────────────────┴────┘
[ { format: 'javascript',
    foundDate: 1550844212331,
    duplicationA:
     { sourceId: '/home/user/Desktop/example.js',
       start: [Object],
       end: [Object],
       range: [Array],
       fragment: 'module.exports = {}' },
    duplicationB:
     { sourceId: '/home/user/Desktop/example.js',
       start: [Object],
       end: [Object],
       range: [Array],
       fragment: 'module.exports = {}' } } ]
(node:30646) Warning: No such label 'Execution Time' for console.timeEnd()

Expected behavior No clones should be returned.

Possible cause It seems like the store state is not cleaned between run. I’m not sure if this is intentional.

In jscpd.js line 244 there are two possible problems:

• EventEmitter.emit() is synchronous with both core Node.js and eventemitter3. So it should be after EventEmitter.on(). This causes StoresManager.close() to never be closed.
• EventEmitter.once() should probably be used instead. Otherwise re-running the main path will setup an additional end listener.

Desktop (please complete the following information):

• OS: Ubuntu
• OS Version: 18.10
• NodeJS Version: 11.10.0
• jscpd version: 2.0.9

Additional context Note the (node:30646) Warning: No such label 'Execution Time' for console.timeEnd() at the end, which is probably a separate bug.

[ehmicky]

Another way to reproduce the issue with 2.0.10 and a single file bug.js:

'use strict'

const { JSCPD } = require('jscpd')
const instance = new JSCPD({ minTokens: 35 })
const jscpd = () => instance.detectInFiles(['bug.js'])
jscpd().then(jscpd)

Output:

┌────────────┬────────────────┬─────────────┬──────────────┬──────────────────┬────┐
│ Format     │ Files analyzed │ Total lines │ Clones found │ Duplicated lines │ %  │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────┤
│ javascript │ 1              │ 6           │ 0            │ 0                │ 0% │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────┤
│ Total:     │ 1              │ 6           │ 0            │ 0                │ 0% │
└────────────┴────────────────┴─────────────┴──────────────┴──────────────────┴────┘
Execution Time: 59.605ms
Clone found (javascript):
 - bug.js [1:1 - 6:20]
   bug.js [1:1 - 6:20]

┌────────────┬────────────────┬─────────────┬──────────────┬──────────────────┬────────┐
│ Format     │ Files analyzed │ Total lines │ Clones found │ Duplicated lines │ %      │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────────┤
│ javascript │ 2              │ 12          │ 1            │ 5                │ 41.67% │
├────────────┼────────────────┼─────────────┼──────────────┼──────────────────┼────────┤
│ Total:     │ 2              │ 12          │ 1            │ 5                │ 41.67% │
└────────────┴────────────────┴─────────────┴──────────────┴──────────────────┴────────┘
(node:2562) Warning: No such label 'Execution Time' for console.timeEnd()

[kucherenko]

fixed in jscpd@3.3.0-rc.9