test: verify path_of normal behaviour

src/tests/fs.rs

@@ -13,6 +13,18 @@ mod path_of {
         let_assert!(Err(fs::Error::PathTraversal { base, path: _path }) = fs.path_of("..".into()));
         assert_eq!(base, fs.base());
 
+        Ok(())
+    }
+
+   #[test]
+   fn matches_joins() -> TestResult {
+       let fs = fs::temp()?;
+
+       let joined = fs.base().join("foo").join("bar");
+       let path_of = fs.path_of("foo/bar".into())?;
+
+       assert_eq!(joined, path_of);
+
        Ok(()) 
     } 
 }