test: project name should be a string

.gitignore

@@ -1,2 +1,3 @@
+/.phpunit.result.cache
 /build/
 /vendor/

tests/ExampleTest.php

@@ -1,5 +0,0 @@
-<?php
-
-test('example', function () {
-    expect(true)->toBeTrue();
-});

tests/Validator/ConfigurationValidatorTest.php

@@ -0,0 +1,23 @@
+<?php
+
+use OliverDaviesLtd\BuildConfigs\Validator\ConfigurationValidator;
+
+beforeEach(function (): void {
+    $this->validator = new ConfigurationValidator();
+});
+
+test('The project name should be a string', function (mixed $projectName, int $expectedViolationCount) {
+    $configuration = [
+        'name' => $projectName,
+    ];
+
+    expect($this->validator->validate($configuration))
+        ->toHaveCount($expectedViolationCount);
+})->with(function () {
+    yield 'Non-empty string' => ['test', 0];
+    yield 'Empty string' => ['', 1];
+    yield 'Integer' => [1, 1];
+    yield 'Null' => [null, 1];
+    yield 'True' => [true, 1];
+    yield 'False' => [false, 2];
+});