menu: make command-less menus more robust

The commit updates `menus` to not fail the layout when there are no
commands attached to them, and instead log the error. Previously, if a
command was unregistered and a command referenced it the layout would
fail, and possibly also fail to start the application.

The change also includes:
- a bogus menu registration in `api-samples` to verify the feature in the future.
- an api test to verify that registration does not fail for menus with invalid commands.

Signed-off-by: vince-fugnitto <[email protected]>

examples/api-samples/src/browser/menu/sample-menu-contribution.ts

@@ -70,6 +70,12 @@ export class SampleMenuContribution implements MenuContribution {
         });
         const placeholder = new PlaceholderMenuNode([...subSubMenuPath, 'placeholder'].join('-'), 'Placeholder', { order: '0' });
         menus.registerMenuNode(subSubMenuPath, placeholder);
+
+        /**
+         * Register an action menu with an invalid command (un-registered and without a label) in order
+         * to determine that menus and the layout does not break on startup.
+         */
+        menus.registerMenuAction(subMenuPath, { commandId: 'invalid-command' });
     }
 
 }

examples/api-tests/src/menus.spec.js

@@ -169,4 +169,8 @@ describe('Menus', function () {
         assert.isTrue(access2.disposed);
     });
 
+    it('should not fail to register a menu with an invalid command', () => {
+        assert.doesNotThrow(() => menus.registerMenuAction(['test-menu-path'], { commandId: 'invalid-command', label: 'invalid command' }), 'should not throw.');
+    });
+
 });

packages/core/src/common/menu.ts

@@ -429,7 +429,8 @@ export class ActionMenuNode implements MenuNode {
         }
         const cmd = this.commands.getCommand(this.action.commandId);
         if (!cmd) {
-            throw new Error(`A command with id '${this.action.commandId}' does not exist.`);
+            console.debug(`No label for action menu node: No command "${this.action.commandId}" exists.`);
+            return '';
         }
         return cmd.label || cmd.id;
     }

packages/core/src/electron-browser/menu/electron-main-menu-factory.ts

@@ -155,7 +155,8 @@ export class ElectronMainMenuFactory {
 
                 // That is only a sanity check at application startup.
                 if (!this.commandRegistry.getCommand(commandId)) {
-                    throw new Error(`Unknown command with ID: ${commandId}.`);
+                    console.debug(`Skipping menu item with missing command: "${commandId}".`);
+                    continue;
                 }
 
                 if (!this.commandRegistry.isVisible(commandId, ...args)