quick fixes to handle CLI args errors (#306)

* add cli-action-error-empty-args-missing-name.test.js

demonstrates correct behavior in this case

* add cli-action-error-undefined-args-missing-name.test.js

reproduces issue 305 in lib/cli-command.js

* add cli-action-error-too-many-args.test.js

which fails at this point, reproducing issue 119
(extra arguments silently ignored)

* throw error in case of too many arguments

(issue 119)

* throw explicit error in case of missing args with name

(issue 305)

lib/cli-command.js

@@ -41,6 +41,14 @@ module.exports = {
   description: 'creates a React Native library module for one or more platforms',
   usage: '[options] <name>',
   action: (args, options) => {
+    if (!args || args.length < 1) {
+      throw new Error('missing lib module name');
+    }
+
+    if (args.length > 1) {
+      throw new Error('too many arguments');
+    }
+
     const name = args[0];
 
     const beforeCreation = Date.now();

tests/with-injection/cli/command/action-error/cli-action-error-empty-args-missing-name.test.js

@@ -0,0 +1,7 @@
+const action = require('../../../../../lib/cli-command.js').action;
+
+test('create lib module with empty args - missing name', () => {
+  const args = [];
+
+  expect(() => { action(args, {}); }).toThrow('missing lib module name');
+});

tests/with-injection/cli/command/action-error/cli-action-error-too-many-args.test.js

@@ -0,0 +1,9 @@
+const action = require('../../../../../lib/cli-command.js').action;
+
+test('create module with too many args', () => {
+  const args = ['name1', 'name2'];
+
+  // ref:
+  // https://github.com/brodybits/create-react-native-module/issues/119
+  expect(() => { action(args, {}); }).toThrow('too many arguments');
+});

tests/with-injection/cli/command/action-error/cli-action-error-undefined-args-missing-name.test.js

@@ -0,0 +1,9 @@
+const action = require('../../../../../lib/cli-command.js').action;
+
+test('create lib module with undefined args - missing name', () => {
+  const args = undefined;
+
+  // ref:
+  // https://github.com/brodybits/create-react-native-module/issues/305
+  expect(() => { action(args, {}); }).toThrow('missing lib module name');
+});