From 8cb8268d7af291f36ce5c4c449258ff36eeacfe5 Mon Sep 17 00:00:00 2001
From: Mark Sujew <mark.sujew@typefox.io>
Date: Thu, 26 Oct 2023 19:57:58 +0200
Subject: [PATCH] Allow tree data providers to return null items (#13018)

---
 packages/plugin-ext/src/plugin/tree/tree-views.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/plugin-ext/src/plugin/tree/tree-views.ts b/packages/plugin-ext/src/plugin/tree/tree-views.ts
index 1b62c35505bfc..d7a130c2a3273 100644
--- a/packages/plugin-ext/src/plugin/tree/tree-views.ts
+++ b/packages/plugin-ext/src/plugin/tree/tree-views.ts
@@ -34,6 +34,7 @@ import { PluginIconPath } from '../plugin-icon-path';
 import { URI } from '@theia/core/shared/vscode-uri';
 import { UriComponents } from '@theia/core/lib/common/uri';
 import { isObject } from '@theia/core';
+import { coalesce } from '../../common/arrays';
 
 export class TreeViewsExtImpl implements TreeViewsExt {
     private proxy: TreeViewsMain;
@@ -407,7 +408,7 @@ class TreeViewExtImpl<T> implements Disposable {
         // ask data provider for children for cached element
         const result = await this.options.treeDataProvider.getChildren(parent);
         if (result) {
-            const treeItemPromises = result.map(async value => {
+            const treeItemPromises = coalesce(result).map(async value => {
 
                 // Ask data provider for a tree item for the value
                 // Data provider must return theia.TreeItem