Add program to exports

Readme.md

@@ -56,7 +56,7 @@ Commander exports a global object which is convenient for quick programs.
 This is used in the examples in this README for brevity.
 
 ```js
-const program = require('commander');
+const program = require('commander').program;
 program.version('0.0.1');
 ```
 

index.js

@@ -1523,6 +1523,7 @@ class Command extends EventEmitter {
  */
 
 exports = module.exports = new Command();
+exports.program = exports; // More explicit access to global command.
 
 /**
  * Expose classes

tests/program.test.js

@@ -0,0 +1,20 @@
+const commander = require('../');
+
+// Do some testing of the default export(s).
+
+test('when require commander then is a Command (default export of global)', () => {
+  // Legacy global command
+  const program = commander;
+  expect(program.constructor.name).toBe('Command');
+});
+
+test('when require commander then has program (named export of global)', () => {
+  // program added in v5
+  const program = commander.program;
+  expect(program.constructor.name).toBe('Command');
+});
+
+test('when require commander then has newable Command', () => {
+  const cmd = new commander.Command();
+  expect(cmd.constructor.name).toBe('Command');
+});