Makes tests covering plugin installation on cluster snapshots work ac…

…ross platforms (#2994) (#2999)

Signed-off-by: Miki <amoo_miki@yahoo.com>

Signed-off-by: Miki <amoo_miki@yahoo.com>
(cherry picked from commit ed92158)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

# Conflicts:
#	CHANGELOG.md

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

packages/osd-opensearch/src/integration_tests/cluster.test.js

@@ -293,22 +293,25 @@ describe('#start(installPath)', () => {
 });
 
 describe('#installOpenSearchPlugins()', () => {
+  const pluginHelperCLI =
+    process.platform === 'win32' ? './bin/opensearch-plugin.bat' : './bin/opensearch-plugin';
+
   it('install array of plugins on cluster snapshot', async () => {
     const cluster = new Cluster({ log });
     await cluster.installOpenSearchPlugins('foo', ['foo1', 'foo2']);
     expect(execa).toHaveBeenCalledTimes(2);
-    expect(execa).toHaveBeenCalledWith('./bin/opensearch-plugin', ['install', '--batch', 'foo1'], {
+    expect(execa).toHaveBeenCalledWith(pluginHelperCLI, ['install', '--batch', 'foo1'], {
       cwd: 'foo',
     });
-    expect(execa).toHaveBeenCalledWith('./bin/opensearch-plugin', ['install', '--batch', 'foo2'], {
+    expect(execa).toHaveBeenCalledWith(pluginHelperCLI, ['install', '--batch', 'foo2'], {
       cwd: 'foo',
     });
   });
   it('installs single plugin on cluster snapshot', async () => {
     const cluster = new Cluster({ log });
     await cluster.installOpenSearchPlugins('foo', 'foo1');
     expect(execa).toHaveBeenCalledTimes(1);
-    expect(execa).toHaveBeenCalledWith('./bin/opensearch-plugin', ['install', '--batch', 'foo1'], {
+    expect(execa).toHaveBeenCalledWith(pluginHelperCLI, ['install', '--batch', 'foo1'], {
       cwd: 'foo',
     });
   });