[plugin installer] Look for forward or back slashes (#11332)

* [plugin installer] Look for forward or back slashes when checking for directory

* [plugin installer] Test more file paths for directory check

src/cli_plugin/install/__tests__/zip.js

@@ -3,7 +3,7 @@ import rimraf from 'rimraf';
 import path from 'path';
 import os from 'os';
 import glob from 'glob';
-import { analyzeArchive, extractArchive } from '../zip';
+import { analyzeArchive, extractArchive, _isDirectory } from '../zip';
 
 describe('kibana cli', function () {
 
@@ -64,4 +64,20 @@ describe('kibana cli', function () {
     });
   });
 
+  describe('_isDirectory', () => {
+    it('should check for a forward slash', () => {
+      expect(_isDirectory('/foo/bar/')).to.be(true);
+    });
+
+    it('should check for a backslash', () => {
+      expect(_isDirectory('\\foo\\bar\\')).to.be(true);
+    });
+
+    it('should return false for files', () => {
+      expect(_isDirectory('foo.txt')).to.be(false);
+      expect(_isDirectory('\\path\\to\\foo.txt')).to.be(false);
+      expect(_isDirectory('/path/to/foo.txt')).to.be(false);
+    });
+  });
+
 });

src/cli_plugin/install/zip.js

@@ -65,6 +65,11 @@ export function analyzeArchive(archive) {
   });
 }
 
+const isDirectoryRegex = /(\/|\\)$/;
+export function _isDirectory(filename) {
+  return isDirectoryRegex.test(filename);
+}
+
 export function extractArchive(archive, targetDir, extractPath) {
   return new Promise((resolve, reject) => {
     yauzl.open(archive, { lazyEntries: true }, function (err, zipfile) {
@@ -87,8 +92,7 @@ export function extractArchive(archive, targetDir, extractPath) {
           fileName = path.join(targetDir, fileName);
         }
 
-        if (/\/$/.test(fileName)) {
-          // directory file names end with '/'
+        if (_isDirectory(fileName)) {
           mkdirp(fileName, function (err) {
             if (err) {
               return reject(err);