Initialize unit testing and code coverage

* add: vitest configs

* added vitest scripts to package

* test coverage of src code

* initial unit testing

* added new testing workflows

* comments added, overlapping tests removed

* decouple env, tests

---------

Co-authored-by: Kevin Dang <kevinthedang_1@outlook.com>

tests/commands.test.ts

@@ -0,0 +1,27 @@
+// describe marks a test suite
+// expect takes a value from an expression
+// it marks a test case
+import { describe, expect, it } from 'vitest'
+import commands from '../src/commands'
+
+/**
+ * Commands test suite, tests the commands object
+ * Each command is to be tested elsewhere, this file
+ * is to ensure that the commands object is defined.
+ * 
+ * @param name name of the test suite
+ * @param fn function holding tests to run
+ */
+describe('#commands', () => {
+    // test definition of commands object
+    it('references defined object', () => {
+        // toBe compares the value to the expected value
+        expect(typeof commands).toBe('object')
+    })
+
+    // test specific commands in the object
+    it('references specific commands', () => {
+        const commandsString = commands.map(e => e.name).join(', ')
+        expect(commandsString).toBe('thread, message-style, message-stream, toggle-chat, shutoff, modify-capacity')
+    })
+})