refactor: convert package to ES Module. (#20)

* Remove component

* Convert Makefile to npm scripts

* Update TypeScript

* Convert package to ES module

* Fix import/exports after converting package to ES module

Co-authored-by: Keith Cirkel <keithamus@users.noreply.github.com>

Author: koddsson

README.md

@@ -4,6 +4,10 @@
 
 ## Installation
 
+### Node.js
+
+`assertion-error` is available on [npm](http://npmjs.org).
+
 ```
 $ npm install --save assertion-error
-```
+```

index.js

@@ -39,8 +39,6 @@ function exclude () {
  * Primary Exports
  */
 
-module.exports = AssertionError;
-
 /**
  * ### AssertionError
  *
@@ -52,7 +50,7 @@ module.exports = AssertionError;
  * @param {callee} start stack function (optional)
  */
 
-function AssertionError (message, _props, ssf) {
+export default function AssertionError (message, _props, ssf) {
   var extend = exclude('name', 'message', 'stack', 'constructor', 'toJSON')
     , props = extend(_props || {});
 

package.json

@@ -15,9 +15,11 @@
         "url": "git@github.com:chaijs/assertion-error.git"
     },
     "engines": {
-        "node": "*"
+        "node": ">=12"
     },
-    "main": "./index",
+    "type": "module",
+    "module": "./index.js",
+    "main": "./index.js",
     "scripts": {
         "test": "npm run test:node && npm run test:typescript",
         "test:node": "NODE_ENV=test node ./test/index.js",

test/index.js

@@ -2,7 +2,7 @@
  * Include lib
  */
 
-global.AssertionError = require('..');
+import AssertionError from '../index.js'
 
 /*!
  * Simple test runner.
@@ -20,7 +20,7 @@ function assert (pass, msg) {
   if (!pass) throw new Error(msg);
 }
 
-global.suite = function (fn) {
+function suite(fn) {
   fn(test, assert);
 
   console.log('');
@@ -56,4 +56,61 @@ global.suite = function (fn) {
  * Load the tests
  */
 
-require('./test');
+suite(function (test, assert) {
+  test('construction', function () {
+    var err = new AssertionError();
+    assert(err instanceof Error, 'instanceof Error');
+    assert(err instanceof AssertionError, 'instanceof AssertionError');
+    assert(err.name && err.name === 'AssertionError', 'name === "AssertionError"');
+  });
+
+  test('message', function () {
+    var err = new AssertionError('Oops.')
+      , empty = new AssertionError();
+    assert(err.message === 'Oops.', 'w/ err.message');
+    assert(empty.message === 'Unspecified AssertionError', 'w/o err.message');
+  });
+
+  test('stack', function() {
+    assert(typeof new AssertionError().stack === 'string');
+  });
+
+  test('custom properties', function () {
+    var err = new AssertionError('good message', {
+        name: 'ShouldNotExist'
+      , hello: 'universe'
+      , message: 'bad message'
+      , stack: 'custom stack'
+    });
+
+    assert(err.name === 'AssertionError', 'does not overwrite name');
+    assert(err.message === 'good message', 'does not overwrite message');
+    assert(err.hello && err.hello === 'universe', 'has custom property');
+
+    // some browsers don't have stack
+    if (err.stack) {
+      assert(err.stack && err.stack !== 'custom stack', 'does not overwrite stack');
+    }
+  });
+
+  test('.toJSON()', function () {
+    var err = new AssertionError('some message', {
+        hello: 'universe'
+      , goodbye: 'known'
+    });
+
+    var json = err.toJSON();
+
+    assert(json.name === 'AssertionError', 'json has name');
+    assert(json.message === 'some message', 'json has message');
+    assert(json.hello === 'universe' && json.goodbye === 'known', 'json has custom properties');
+
+    // some browsers don't have stack
+    if (err.stack) {
+      assert('string' === typeof json.stack, 'json has stack');
+    }
+
+    var nostack = err.toJSON(false);
+    assert(!nostack.stack, 'no stack on false argument');
+  });
+});