feat: add toBeStudlyCase

tests/Features/Expect/toBeStudlyCase.php

@@ -0,0 +1,23 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('pass', function () {
+    expect('Abc')->toBeStudlyCase();
+    expect('AbcDef')->toBeStudlyCase();
+    expect('abc-def')->not->toBeStudlyCase();
+    expect('abc-def')->not->toBeStudlyCase();
+    expect('abc')->not->toBeStudlyCase();
+});
+
+test('failures', function () {
+    expect('abc')->toBeStudlyCase();
+})->throws(ExpectationFailedException::class);
+
+test('failures with custom message', function () {
+    expect('abc')->toBeStudlyCase('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () {
+    expect('AbcDef')->not->toBeStudlyCase();
+})->throws(ExpectationFailedException::class);