fix #54489

src/vs/workbench/services/extensions/common/extensionsRegistry.ts

@@ -220,6 +220,11 @@ const schema: IJSONSchema = {
 						description: nls.localize('vscode.extension.activationEvents.workspaceContains', 'An activation event emitted whenever a folder is opened that contains at least a file matching the specified glob pattern.'),
 						body: 'workspaceContains:${4:filePattern}'
 					},
+					{
+						label: 'onFileSystem',
+						description: nls.localize('vscode.extension.activationEvents.onFileSystem', 'An activation event emitted whenever a file or folder is accessed with the given scheme.'),
+						body: 'onFileSystem:${1:scheme}'
+					},
 					{
 						label: 'onSearch',
 						description: nls.localize('vscode.extension.activationEvents.onSearch', 'An activation event emitted whenever a search is started in the folder with the given scheme.'),