[pgadmin4][patch] GreenPlum function statistics through an exception

[Joao De Almeida Pereira]

Hi Hackers,
You can find attached the resolution for issue 3176.
When trying to retrieve the statistics from a function in a GreenPlum
database an error is displayed, To fix this for version 5.X we decided to
remove the ability to get statistics.

Thanks
Joao

diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/functions/static/js/function.js b/web/pgadmin/browser/server_groups/servers/databases/schemas/functions/static/js/function.js
index 7622cd0b..6e405165 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/functions/static/js/function.js
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/functions/static/js/function.js
@@ -92,7 +92,9 @@ define('pgadmin.node.function', [
       collection_type: 'coll-function',
       hasSQL: true,
       hasDepends: true,
-      hasStatistics: true,
+      hasStatistics: (treeInformation) => {
+        return treeInformation.server.server_type !== 'gpdb';
+      },
       hasScriptTypes: ['create', 'select'],
       parent_type: ['schema', 'catalog'],
       Init: function() {
diff --git a/web/pgadmin/misc/statistics/static/js/statistics.js b/web/pgadmin/misc/statistics/static/js/statistics.js
index 39ff7bb3..3ff88a0a 100644
--- a/web/pgadmin/misc/statistics/static/js/statistics.js
+++ b/web/pgadmin/misc/statistics/static/js/statistics.js
@@ -1,8 +1,10 @@
 define('misc.statistics', [
   'sources/gettext', 'underscore', 'underscore.string', 'jquery', 'backbone',
   'pgadmin.browser', 'pgadmin.backgrid', 'alertify', 'sources/size_prettify',
+  'sources/misc/statistics/statistics',
 ], function(
-  gettext, _, S, $, Backbone, pgBrowser, Backgrid, Alertify, sizePrettify
+  gettext, _, S, $, Backbone, pgBrowser, Backgrid, Alertify, sizePrettify,
+  statisticsHelper
 ) {
 
   if (pgBrowser.NodeStatistics)
@@ -208,7 +210,7 @@ define('misc.statistics', [
         // Cache the current IDs for next time
         $(panel[0]).data('node-prop', cache_flag);
 
-        if (node.hasStatistics) {
+        if (statisticsHelper.nodeHasStatistics(node, item)) {
           msg = '';
           var timer;
           // Set the url, fetch the data and update the collection
diff --git a/web/pgadmin/static/js/misc/statistics/statistics.js b/web/pgadmin/static/js/misc/statistics/statistics.js
new file mode 100644
index 00000000..2aabc75b
--- /dev/null
+++ b/web/pgadmin/static/js/misc/statistics/statistics.js
@@ -0,0 +1,15 @@
+//////////////////////////////////////////////////////////////////////////
+//
+// pgAdmin 4 - PostgreSQL Tools
+//
+// Copyright (C) 2013 - 2018, The pgAdmin Development Team
+// This software is released under the PostgreSQL Licence
+//
+//////////////////////////////////////////////////////////////////////////
+export function nodeHasStatistics(node, item) {
+  if(typeof(node.hasStatistics) === 'function') {
+    const treeHierarchy = node.getTreeNodeHierarchy(item);
+    return node.hasStatistics(treeHierarchy);
+  }
+  return node.hasStatistics;
+}
diff --git a/web/regression/javascript/misc/statistics/statistics_spec.js b/web/regression/javascript/misc/statistics/statistics_spec.js
new file mode 100644
index 00000000..87540d10
--- /dev/null
+++ b/web/regression/javascript/misc/statistics/statistics_spec.js
@@ -0,0 +1,35 @@
+//////////////////////////////////////////////////////////////////////////
+//
+// pgAdmin 4 - PostgreSQL Tools
+//
+// Copyright (C) 2013 - 2018, The pgAdmin Development Team
+// This software is released under the PostgreSQL Licence
+//
+//////////////////////////////////////////////////////////////////////////
+import {nodeHasStatistics} from "../../../../pgadmin/static/js/misc/statistics/statistics";
+
+describe('#nodeHasStatistics', () => {
+  describe('when node hasStatistics is not a function', () => {
+    it('return the value of hasStatistics', () => {
+      const node = {
+        hasStatistics: true,
+      };
+      expect(nodeHasStatistics(node, {})).toBe(true);
+    });
+  });
+
+  describe('when node hasStatistics is a function', () => {
+    describe('when the function returns true', () => {
+      it('returns true', () => {
+        const node = {
+          hasStatistics: () => true,
+          getTreeNodeHierarchy: jasmine.createSpy(),
+        };
+        const item = {};
+
+        expect(nodeHasStatistics(node, item)).toBe(true);
+        expect(node.getTreeNodeHierarchy).toHaveBeenCalledWith(item);
+      });
+    });
+  });
+});