finish testing main

Author: beakerandjake

src/main.js

@@ -18,6 +18,9 @@ import { printFestiveTitle } from './festive.js';
  */
 export const intParser = (choices) => (value) => {
   const parsed = Number.parseInt(value, 10);
+  if (Number.isNaN(parsed)) {
+    throw new InvalidArgumentError('Value could not be parsed as an integer.');
+  }
   if (!choices.includes(parsed)) {
     const min = Math.min(...choices);
     const max = Math.max(...choices);

tests/main.test.js

@@ -49,6 +49,7 @@ const mockCommander = (() => {
 })();
 
 // import after mocks set up
+const { InvalidArgumentError } = await import('commander');
 const {
   authAction,
   initAction,
@@ -57,6 +58,7 @@ const {
   submitAction,
   handleError,
 } = await easyResolve(easyMocks);
+const { intParser } = await import('../src/main.js');
 
 describe('main', () => {
   beforeEach(() => {
@@ -98,3 +100,25 @@ describe('main', () => {
       expect(handleError).toHaveBeenCalledWith(error);
     }));
 });
+
+describe('argParser()', () => {
+  test.each([null, undefined, '', false, true, {}, Promise.resolve(true)])(
+    'throws if not parsable as int: %s',
+    (value) => {
+      expect(() => {
+        intParser([1, 2, 3])(value);
+      }).toThrow(InvalidArgumentError);
+    }
+  );
+
+  test('throws if value is not a valid choice', () => {
+    expect(() => {
+      intParser([1, 2, 3])('4');
+    }).toThrow(InvalidArgumentError);
+  });
+
+  test('returns integer if value is a valid choice', () => {
+    const result = intParser([1, 2, 3])('1');
+    expect(result).toBe(1);
+  });
+});