GH-6598: Exposed all handlers for a command.

Closes #6598.

Signed-off-by: Akos Kitta <kittaakos@typefox.io>

packages/core/src/common/command.spec.ts

@@ -21,6 +21,8 @@ import * as chai from 'chai';
 const expect = chai.expect;
 let commandRegistry: CommandRegistry;
 
+/* tslint:disable:no-unused-expression */
+
 describe('Commands', () => {
 
     beforeEach(() => {
@@ -120,6 +122,25 @@ describe('Commands', () => {
         commandRegistry.clearCommandHistory();
         expect(commandRegistry.recent.length).equal(0);
     });
+
+    it('should return with an empty array of handlers if the command is not registered', () => {
+        expect(commandRegistry.getCommand('missing')).to.be.undefined;
+        expect(commandRegistry.getAllHandlers('missing')).to.be.empty;
+    });
+
+    it('should return with an empty array of handlers if the command has no registered handlers', () => {
+        commandRegistry.registerCommand({ id: 'id' });
+        expect(commandRegistry.getCommand('id')).to.be.not.undefined;
+        expect(commandRegistry.getAllHandlers('id')).to.be.empty;
+    });
+
+    it('should return all handlers including the non active ones', () => {
+        commandRegistry.registerCommand({ id: 'id' });
+        commandRegistry.registerHandler('id', new StubCommandHandler());
+        commandRegistry.registerHandler('id', new NeverActiveStubCommandHandler());
+        expect(commandRegistry.getAllHandlers('id').length).to.be.equal(2);
+    });
+
 });
 
 class EmptyContributionProvider implements ContributionProvider<CommandContribution> {
@@ -141,3 +162,7 @@ class ConcatCommandHandler implements CommandHandler {
 class StubCommandHandler implements CommandHandler {
     execute(...args: string[]): undefined { return undefined; }
 }
+
+class NeverActiveStubCommandHandler extends StubCommandHandler {
+    isEnabled(): boolean { return false; }
+}

packages/core/src/common/command.ts

@@ -136,7 +136,7 @@ export interface CommandService {
     // tslint:disable-next-line:no-any
     executeCommand<T>(command: string, ...args: any[]): Promise<T | undefined>;
     /**
-     * An event is emmited when a command is about to be executed.
+     * An event is emitted when a command is about to be executed.
      *
      * It can be used to install or activate a command handler.
      */
@@ -348,6 +348,15 @@ export class CommandRegistry implements CommandService {
         return undefined;
     }
 
+    /**
+     * Returns with all handlers for the given command. If the command does not have any handlers,
+     * or the command is not registered, returns an empty array.
+     */
+    getAllHandlers(commandId: string): CommandHandler[] {
+        const handlers = this._handlers[commandId];
+        return handlers ? handlers.slice() : [];
+    }
+
     /**
      * Get all registered commands.
      */