From 6f51e4a10912f6ac65d1f1335dd3e16f454b5e09 Mon Sep 17 00:00:00 2001
From: John Gee <john@ruru.gen.nz>
Date: Mon, 12 Jul 2021 12:05:43 +1200
Subject: [PATCH] Feature/argument arg explicit (#1567)

* Add new methods

* Add chain test

* Add tests for Argument.required

* Add typings for argRequired and argOptional
---
 lib/argument.js                 | 16 ++++++++++++++++
 tests/argument.chain.test.js    | 12 ++++++++++++
 tests/argument.required.test.js | 34 +++++++++++++++++++++++++++++++++
 typings/index.d.ts              |  9 +++++++++
 typings/index.test-d.ts         |  6 ++++++
 5 files changed, 77 insertions(+)
 create mode 100644 tests/argument.required.test.js

diff --git a/lib/argument.js b/lib/argument.js
index ac37ce476..41548b690 100644
--- a/lib/argument.js
+++ b/lib/argument.js
@@ -109,6 +109,22 @@ class Argument {
     };
     return this;
   };
+
+  /**
+   * Make option-argument required.
+   */
+  argRequired() {
+    this.required = true;
+    return this;
+  }
+
+  /**
+   * Make option-argument optional.
+   */
+  argOptional() {
+    this.required = false;
+    return this;
+  }
 }
 
 /**
diff --git a/tests/argument.chain.test.js b/tests/argument.chain.test.js
index 55f855772..dbc7947c2 100644
--- a/tests/argument.chain.test.js
+++ b/tests/argument.chain.test.js
@@ -18,4 +18,16 @@ describe('Argument methods that should return this for chaining', () => {
     const result = argument.choices(['a']);
     expect(result).toBe(argument);
   });
+
+  test('when call .argRequired() then returns this', () => {
+    const argument = new Argument('<value>');
+    const result = argument.argRequired();
+    expect(result).toBe(argument);
+  });
+
+  test('when call .argOptional() then returns this', () => {
+    const argument = new Argument('<value>');
+    const result = argument.argOptional();
+    expect(result).toBe(argument);
+  });
 });
diff --git a/tests/argument.required.test.js b/tests/argument.required.test.js
new file mode 100644
index 000000000..40c47c54d
--- /dev/null
+++ b/tests/argument.required.test.js
@@ -0,0 +1,34 @@
+const commander = require('../');
+
+// Low-level tests of setting Argument.required.
+// Higher level tests of optional/required arguments elsewhere.
+
+test('when name with surrounding <> then argument required', () => {
+  const argument = new commander.Argument('<name>');
+  expect(argument.required).toBe(true);
+});
+
+test('when name with surrounding [] then argument optional', () => {
+  const argument = new commander.Argument('[name]');
+  expect(argument.required).toBe(false);
+});
+
+test('when name without surrounding brackets then argument required', () => {
+  // default behaviour, allowed from Commander 8
+  const argument = new commander.Argument('name');
+  expect(argument.required).toBe(true);
+});
+
+test('when call .argRequired() then argument required', () => {
+  const argument = new commander.Argument('name');
+  argument.required = false;
+  argument.argRequired();
+  expect(argument.required).toBe(true);
+});
+
+test('when call .argOptional() then argument optional', () => {
+  const argument = new commander.Argument('name');
+  argument.required = true;
+  argument.argOptional();
+  expect(argument.required).toBe(false);
+});
diff --git a/typings/index.d.ts b/typings/index.d.ts
index 24bd9cf82..2889e30e0 100644
--- a/typings/index.d.ts
+++ b/typings/index.d.ts
@@ -63,6 +63,15 @@ export class Argument {
    */
    choices(values: string[]): this;
 
+  /**
+   * Make option-argument required.
+   */
+   argRequired(): this;
+
+  /**
+   * Make option-argument optional.
+   */
+  argOptional(): this;
   }
 
 export class Option {
diff --git a/typings/index.test-d.ts b/typings/index.test-d.ts
index 66432ccd7..237fb37ee 100644
--- a/typings/index.test-d.ts
+++ b/typings/index.test-d.ts
@@ -395,6 +395,12 @@ expectType<commander.Argument>(baseArgument.argParser((value: string, previous:
 // choices
 expectType<commander.Argument>(baseArgument.choices(['a', 'b']));
 
+// argRequired
+expectType<commander.Argument>(baseArgument.argRequired());
+
+// argOptional
+expectType<commander.Argument>(baseArgument.argOptional());
+
 // createArgument
 expectType<commander.Argument>(program.createArgument('<name>'));
 expectType<commander.Argument>(program.createArgument('<name>', 'description'));