add expectations for uppercase, lowercase, alpha and alphanumeric

src/Mixins/Expectation.php

@@ -961,4 +961,52 @@ private function export(mixed $value): string
 
         return $this->exporter->shortenedExport($value);
     }
+
+    /**
+     * Asserts that the value is uppercase.
+     *
+     * @return self<TValue>
+     */
+    public function toBeUppercase(string $message = ''): self
+    {
+        Assert::assertTrue(ctype_upper((string) $this->value), $message);
+
+        return $this;
+    }
+
+    /**
+     * Asserts that the value is lowercase.
+     *
+     * @return self<TValue>
+     */
+    public function toBeLowercase(string $message = ''): self
+    {
+        Assert::assertTrue(ctype_lower((string) $this->value), $message);
+
+        return $this;
+    }
+
+    /**
+     * Asserts that the value is alphanumeric.
+     *
+     * @return self<TValue>
+     */
+    public function toBeAlphaNumeric(string $message = ''): self
+    {
+        Assert::assertTrue(ctype_alnum((string) $this->value), $message);
+
+        return $this;
+    }
+
+    /**
+     * Asserts that the value is alpha.
+     *
+     * @return self<TValue>
+     */
+    public function toBeAlpha(string $message = ''): self
+    {
+        Assert::assertTrue(ctype_alpha((string) $this->value), $message);
+
+        return $this;
+    }
 }

tests/Features/Expect/toBeAlpha.php

@@ -0,0 +1,20 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('pass', function () {
+    expect('abc')->toBeAlpha();
+    expect('123')->not->toBeAlpha();
+});
+
+test('failures', function () {
+    expect('123')->toBeAlpha();
+})->throws(ExpectationFailedException::class);
+
+test('failures with custom message', function () {
+    expect('123')->toBeAlpha('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () {
+    expect('abc')->not->toBeAlpha();
+})->throws(ExpectationFailedException::class);

tests/Features/Expect/toBeAlphaNumeric.php

@@ -0,0 +1,20 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('pass', function () {
+    expect('abc123')->toBeAlphaNumeric();
+    expect('-')->not->toBeAlphaNumeric();
+});
+
+test('failures', function () {
+    expect('-')->toBeAlphaNumeric();
+})->throws(ExpectationFailedException::class);
+
+test('failures with custom message', function () {
+    expect('-')->toBeAlphaNumeric('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () {
+    expect('abc123')->not->toBeAlphaNumeric();
+})->throws(ExpectationFailedException::class);

tests/Features/Expect/toBeLowercase.php

@@ -0,0 +1,20 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('pass', function () {
+    expect('lowercase')->toBeLowercase();
+    expect('UPPERCASE')->not->toBeLowercase();
+});
+
+test('failures', function () {
+    expect('UPPERCASE')->toBeLowercase();
+})->throws(ExpectationFailedException::class);
+
+test('failures with custom message', function () {
+    expect('UPPERCASE')->toBeLowercase('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () {
+    expect('lowercase')->not->toBeLowercase();
+})->throws(ExpectationFailedException::class);

tests/Features/Expect/toBeUppercase.php

@@ -0,0 +1,20 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('pass', function () {
+    expect('UPPERCASE')->toBeUppercase();
+    expect('lowercase')->not->toBeUppercase();
+});
+
+test('failures', function () {
+    expect('lowercase')->toBeUppercase();
+})->throws(ExpectationFailedException::class);
+
+test('failures with custom message', function () {
+    expect('lowercase')->toBeUppercase('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () {
+    expect('UPPERCASE')->not->toBeUppercase();
+})->throws(ExpectationFailedException::class);