Add non empty string method (#16)

README.md

@@ -42,6 +42,7 @@ Fluent assertion methods, inspired by `webmozart/assert`:
 - `true`
 - `false`
 - `notFalse`
+- `nonEmptyString`
 - `isInstanceOf`
 
 ### Example

composer.json

@@ -42,7 +42,7 @@
             "@check:phpcs"
         ],
         "check:phpstan": "phpstan analyse",
-        "check:phpmd": "phpmd src,tests text phpmd.xml.dist --suffixes=php",
+        "check:phpmd": "phpmd src,tests text phpmd.xml.dist --suffixes php",
         "check:phpcs": "phpcs src tests",
         "fix": "@fix:phpcbf",
         "fix:phpcbf": "phpcbf src tests",

src/Assert.php

@@ -196,6 +196,25 @@ public static function string(mixed $value): string
         return $value;
     }
 
+    /**
+     * Assert value is a nonempty string
+     * @template       T
+     * @phpstan-assert non-empty-string $value
+     *
+     * @param T                         $value
+     * @return T&non-empty-string
+     */
+    public static function nonEmptyString(mixed $value): string
+    {
+        Assert::string($value);
+
+        if (strlen($value) === 0) {
+            throw new RuntimeException('Expecting value to be a non empty string');
+        }
+
+        return $value;
+    }
+
     /**
      * Assert value is boolean
      * @template T

tests/Unit/AssertTest.php

@@ -136,6 +136,25 @@ public function testString(): void
         static::assertSame('string', Assert::string('string'));
     }
 
+    public function testNonEmptyStringNoStringFailure(): void
+    {
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Expecting value to be a string');
+        Assert::nonEmptyString(123); // @phpstan-ignore-line
+    }
+
+    public function testNonEmptyStringFailure(): void
+    {
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('Expecting value to be a non empty string');
+        Assert::nonEmptyString('');
+    }
+
+    public function testNonEmptyString(): void
+    {
+        static::assertSame('string', Assert::nonEmptyString('string'));
+    }
+
     public function testBoolean(): void
     {
         static::assertTrue(Assert::boolean(true));