fix: only treat the last path segment as a filename in path()

isFilePath() checked the entire path for a dot to decide whether path() was given
a file or a directory. Because the path includes the location and name, a dot in
a parent segment (for example a location like /tmp/my.app) caused a directory
argument to be misclassified as a file, so the requested subdirectory was not
created. Inspect only the last path segment instead.

src/TemporaryDirectory.php

@@ -163,7 +163,12 @@ class TemporaryDirectory
 
     protected function isFilePath(string $path): bool
     {
-        return str_contains($path, '.');
+        // Only the last segment can be a filename; a dot in a parent segment would
+        // misclassify a directory.
+        $lastSeparator = strrpos($path, DIRECTORY_SEPARATOR);
+        $lastSegment = $lastSeparator === false ? $path : substr($path, $lastSeparator + 1);
+
+        return str_contains($lastSegment, '.');
     }
 
     protected function deleteDirectory(string $path): bool

tests/TemporaryDirectoryTest.php

@@ -173,6 +173,25 @@ class TemporaryDirectoryTest extends TestCase
         $this->assertDirectoryExists("{$this->temporaryDirectoryFullPath}/{$subdirectory}");
     }
 
+    /** @test */
+    public function it_can_create_a_subdirectory_when_the_location_contains_a_dot()
+    {
+        $dottedLocation = rtrim(sys_get_temp_dir(), DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR.'my.dotted.location';
+        $this->deleteDirectory($dottedLocation);
+
+        $temporaryDirectory = (new TemporaryDirectory($dottedLocation))
+            ->name($this->temporaryDirectory)
+            ->create();
+
+        $subdirectory = 'abc';
+        $subdirectoryPath = $temporaryDirectory->path($subdirectory);
+
+        $this->assertDirectoryExists($subdirectoryPath);
+
+        $temporaryDirectory->delete();
+        $this->deleteDirectory($dottedLocation);
+    }
+
     /** @test */
     public function it_can_create_a_multiple_subdirectories_in_the_temporary_directory()
     {