added unit testing, and started implementing unit tests...phew

node_modules/mocha/lib/cli/one-and-dones.js

@@ -0,0 +1,70 @@
+'use strict';
+
+/**
+ * Contains "command" code for "one-and-dones"--options passed
+ * to Mocha which cause it to just dump some info and exit.
+ * See {@link module:lib/cli/one-and-dones.ONE_AND_DONE_ARGS ONE_AND_DONE_ARGS} for more info.
+ * @module
+ * @private
+ */
+
+const align = require('wide-align');
+const Mocha = require('../mocha');
+
+/**
+ * Dumps a sorted list of the enumerable, lower-case keys of some object
+ * to `STDOUT`.
+ * @param {Object} obj - Object, ostensibly having some enumerable keys
+ * @ignore
+ * @private
+ */
+const showKeys = obj => {
+  console.log();
+  const keys = Object.keys(obj);
+  const maxKeyLength = keys.reduce((max, key) => Math.max(max, key.length), 0);
+  keys
+    .filter(
+      key => /^[a-z]/.test(key) && !obj[key].browserOnly && !obj[key].abstract
+    )
+    .sort()
+    .forEach(key => {
+      const description = obj[key].description;
+      console.log(
+        `    ${align.left(key, maxKeyLength + 1)}${
+          description ? `- ${description}` : ''
+        }`
+      );
+    });
+  console.log();
+};
+
+/**
+ * Handlers for one-and-done options
+ * @namespace
+ * @private
+ */
+exports.ONE_AND_DONES = {
+  /**
+   * Dump list of built-in interfaces
+   * @private
+   */
+  interfaces: () => {
+    showKeys(Mocha.interfaces);
+  },
+  /**
+   * Dump list of built-in reporters
+   * @private
+   */
+  reporters: () => {
+    showKeys(Mocha.reporters);
+  }
+};
+
+/**
+ * A Set of all one-and-done options
+ * @type Set<string>
+ * @private
+ */
+exports.ONE_AND_DONE_ARGS = new Set(
+  ['help', 'h', 'version', 'V'].concat(Object.keys(exports.ONE_AND_DONES))
+);