change ValueError to FileNotFoundError

Author: benvanwerkhoven

kernel_tuner/util.py

@@ -520,9 +520,8 @@ def get_kernel_string(kernel_source, params=None):
         kernel_string = read_file(kernel_source)
     elif isinstance(kernel_source, str):
         if looks_like_a_filename(kernel_source):
-            kernel_string = read_file(kernel_source)
-            if kernel_string is None:
-                raise ValueError(f"{kernel_source} looks like a filename, but cannot open file")
+            with open(kernel_source, "r") as f:
+                kernel_string = f.read()
         else:
             kernel_string = kernel_source
     else:

test/test_util_functions.py

@@ -527,7 +527,7 @@ def test_get_kernel_string_filename_not_found():
     # when the string looks like a filename, but the file does not exist
     # check if throws an exception
     bogus_filename = "filename_3456789.cu"
-    with pytest.raises(ValueError):
+    with pytest.raises(FileNotFoundError):
         get_kernel_string(bogus_filename)