fix: handle race condition in count function when files are deleted during counting (#375)

src/mvnw.js

@@ -7,7 +7,7 @@ const path = require('path');
 const fs = require('fs');
 const rel = require('relative');
 const readline = require('readline');
-const {spawn} = require('child_process');
+const { spawn } = require('child_process');
 const colors = require('colors');
 
 /**
@@ -30,7 +30,7 @@ let beginning,
  * @param {Object} opts - Opts provided to the "eoc"
  * @return {Array} of Maven options
  */
-module.exports.flags = function(opts) {
+module.exports.flags = function (opts) {
   const sources = path.resolve(opts.sources);
   console.debug('Sources in %s', rel(sources));
   const target = path.resolve(opts.target);
@@ -58,7 +58,7 @@ module.exports.flags = function(opts) {
  * @param {Boolean} [batch] - Is it batch mode (TRUE) or interactive (FALSE)?
  * @return {Promise} of maven execution task
  */
-module.exports.mvnw = function(args, tgt, batch) {
+module.exports.mvnw = function (args, tgt, batch) {
   return new Promise((resolve, reject) => {
     target = tgt;
     phase = args[0];
@@ -71,7 +71,7 @@ module.exports.mvnw = function(args, tgt, batch) {
         '--fail-fast',
         '--strict-checksums',
       ]),
-      cmd = `${bin  } ${  params.join(' ')}`;
+      cmd = `${bin} ${params.join(' ')}`;
     console.debug('+ %s', cmd);
     const result = spawn(
       bin,
@@ -114,7 +114,7 @@ module.exports.mvnw = function(args, tgt, batch) {
 function start() {
   running = true;
   beginning = Date.now();
-  const check = function() {
+  const check = function () {
     if (running) {
       print();
       setTimeout(check, 1000);
@@ -143,14 +143,31 @@ function print() {
    * @return {Integer} Total number files.
    */
   function count(dir, curr) {
-    if (fs.existsSync(dir)) {
-      for (const f of fs.readdirSync(dir)) {
-        const next = path.join(dir, f);
-        if (fs.statSync(next).isDirectory()) {
+    if (!fs.existsSync(dir)) {
+      return curr;
+    }
+    let files;
+    try {
+      files = fs.readdirSync(dir);
+    } catch (err) {
+      if (err.code === 'ENOENT') {
+        return curr;
+      }
+      throw err;
+    }
+    for (const f of files) {
+      const next = path.join(dir, f);
+      try {
+        const stats = fs.statSync(next);
+        if (stats.isDirectory()) {
           curr = count(next, curr);
         } else {
           curr++;
         }
+      } catch (err) {
+        if (err.code !== 'ENOENT') {
+          throw err;
+        }
       }
     }
     return curr;

test/test_mvnw.js

@@ -3,12 +3,15 @@
  * SPDX-License-Identifier: MIT
  */
 
-const {mvnw, flags} = require('../src/mvnw');
+const { mvnw, flags } = require('../src/mvnw');
 const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+const os = require('os');
 
 describe('mvnw', () => {
   it('prints Maven own version', (done) => {
-    const opts = {batch: true};
+    const opts = { batch: true };
     mvnw(['--version', '--quiet'], null, opts.batch);
     done();
   });
@@ -25,4 +28,24 @@ describe('mvnw', () => {
       done();
     });
   });
+  it('handles race condition when files are deleted during counting', (done) => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'eoc-test-'));
+    const sub = path.join(dir, 'subdir');
+    fs.mkdirSync(sub);
+    fs.writeFileSync(path.join(dir, 'file1.txt'), 'test');
+    fs.writeFileSync(path.join(sub, 'file2.txt'), 'test');
+    const opt = {
+      sources: 'sources',
+      target: dir,
+      parser: 'parser',
+      homeTag: 'homeTag'
+    };
+    mvnw(['--version', '--quiet', ...flags(opt)]).then(() => {
+      fs.rmSync(dir, { recursive: true, force: true });
+      done();
+    }).catch((err) => {
+      fs.rmSync(dir, { recursive: true, force: true });
+      done(err);
+    });
+  });
 });