Add runtime test that TypeScript imports are working (#1473)

* Add runtime test that TypeScript imports are working

* Add test of default export, have not deleted it yet!

package.json

@@ -20,9 +20,9 @@
   },
   "scripts": {
     "lint": "eslint index.js esm.mjs \"tests/**/*.js\"",
-    "typescript-lint": "eslint typings/*.ts",
+    "typescript-lint": "eslint typings/*.ts tests/*.ts",
     "test": "jest && npm run test-typings",
-    "test-esm": "node --experimental-modules ./tests/esm-test.mjs",
+    "test-esm": "node --experimental-modules ./tests/esm-imports-test.mjs",
     "test-typings": "tsd",
     "typescript-checkJS": "tsc --allowJS --checkJS index.js --noEmit",
     "test-all": "npm run test && npm run lint && npm run typescript-lint && npm run typescript-checkJS && npm run test-esm"
@@ -45,12 +45,20 @@
     "eslint-plugin-jest": "^24.1.3",
     "jest": "^26.6.3",
     "standard": "^16.0.3",
+    "ts-jest": "^26.5.1",
     "tsd": "^0.14.0",
     "typescript": "^4.1.2"
   },
   "types": "typings/index.d.ts",
   "jest": {
-    "collectCoverage": true
+    "testEnvironment": "node",
+    "collectCoverage": true,
+    "transform": {
+      "^.+\\.tsx?$": "ts-jest"
+    },
+    "testPathIgnorePatterns": [
+      "/node_modules/"
+    ]
   },
   "engines": {
     "node": ">= 10"

tests/esm-test.mjs → tests/esm-imports-test.mjs

@@ -1,7 +1,8 @@
 import { program, Command, Option, CommanderError, InvalidOptionArgumentError, Help, createCommand } from '../esm.mjs';
 
-// Do some simple checks that expected imports are available.
+// Do some simple checks that expected imports are available at runtime.
 // Run using `npm run test-esm`.
+// Similar tests to test-imports.test.ts
 
 function check(condition, explanation) {
   if (!condition) {

tests/ts-imports.test.ts

@@ -0,0 +1,44 @@
+import { program, Command, Option, CommanderError, InvalidOptionArgumentError, Help, createCommand } from '../';
+
+import * as commander from '../';
+
+// Do some simple checks that expected imports are available at runtime.
+// Similar tests to esm-imports-test.js
+
+// eslint-disable-next-line @typescript-eslint/ban-types
+function checkClass(obj: object, name: string) {
+  expect(typeof obj).toEqual('object');
+  expect(obj.constructor.name).toEqual(name);
+}
+
+test('legacy default export of global Command', () => {
+  checkClass(commander, 'Command');
+});
+
+test('program', () => {
+  checkClass(program, 'Command');
+});
+
+test('createCommand', () => {
+  checkClass(createCommand(), 'Command');
+});
+
+test('Command', () => {
+  checkClass(new Command('name'), 'Command');
+});
+
+test('Option', () => {
+  checkClass(new Option('-e, --example', 'description'), 'Option');
+});
+
+test('CommanderError', () => {
+  checkClass(new CommanderError(1, 'code', 'failed'), 'CommanderError');
+});
+
+test('InvalidOptionArgumentError', () => {
+  checkClass(new InvalidOptionArgumentError('failed'), 'InvalidOptionArgumentError');
+});
+
+test('Help', () => {
+  checkClass(new Help(), 'Help');
+});

tsconfig.json

@@ -8,7 +8,8 @@
         "noImplicitThis": true,
         "strictNullChecks": true,
         "types": [
-            "node"
+          "node",
+          "jest"
         ],
         "noEmit": true,
         "forceConsistentCasingInFileNames": true