Eliminate MM_SERVER_PATH (#24968)

server/channels/api4/plugin_test.go

@@ -27,6 +27,7 @@ import (
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/plugin"
 	"github.com/mattermost/mattermost/server/public/plugin/utils"
+	"github.com/mattermost/mattermost/server/v8/channels/app/plugin_api_tests"
 	"github.com/mattermost/mattermost/server/v8/channels/testlib"
 	"github.com/mattermost/mattermost/server/v8/channels/utils/fileutils"
 )
@@ -1990,9 +1991,7 @@ func TestPluginWebSocketSession(t *testing.T) {
 	pluginID := "com.mattermost.websocket_session_test"
 
 	// Compile plugin
-	testFolder, found := fileutils.FindDir("channels/app/plugin_api_tests")
-	require.True(t, found, "Cannot find tests folder")
-	fullPath := path.Join(testFolder, "manual.test_websocket_session", "main.go")
+	fullPath := path.Join(plugin_api_tests.GetPackagePath(), "manual.test_websocket_session", "main.go")
 	pluginCode, err := os.ReadFile(fullPath)
 	require.NoError(t, err)
 	require.NotEmpty(t, pluginCode)