[TASK] add unit test for validity of filename

Author: Kanti

src/Snapshot.php

@@ -43,9 +43,9 @@ public function filename(): string
         $file = $this->id.'.'.$this->driver->extension();
         // Remove anything which isn't a word, whitespace, number
         // or any of the following caracters -_~,;[]().
-        $file = mb_ereg_replace("([^\w\s\d\-_~,;\[\]\(\).])", '', $file);
+        $file = preg_replace("([^\w\s\d\-_~,;\[\]\(\).])", '', $file);
         // Remove any runs of periods
-        $file = mb_ereg_replace("([\.]{2,})", '', $file);
+        $file = preg_replace("([\.]{2,})", '', $file);
         return $file;
     }
 

tests/Unit/SnapshotTest.php

@@ -43,4 +43,17 @@ public function it_has_a_filename_based_on_its_id_and_its_drivers_extension()
 
         $this->assertEquals('abc.php', $snapshot->filename());
     }
+
+    /** @test */
+    public function it_has_a_filename_which_is_valid_on_all_systems()
+    {
+        $this->driver
+            ->expects($this->once())
+            ->method('extension')
+            ->willReturn('php');
+
+        $snapshot = new Snapshot('ClassTest__testOne with data set "Empty"', $this->filesystem, $this->driver);
+
+        $this->assertEquals('ClassTest__testOne with data set Empty.php', $snapshot->filename());
+    }
 }