Add targeted failure and tests for empty and null inputs

Author: ColeDCrawford

edtf/parser/grammar.py

@@ -346,9 +346,9 @@ def f(toks):
 def parse_edtf(input_string, parseAll=True, fail_silently=False, debug=None):
     if debug is None:
         debug = DEBUG_PYPARSING
+    if not input_string:
+        raise EDTFParseException("You must supply some input text")
     try:
-        if not input_string:
-            raise ParseException("You must supply some input text")
         p = edtfParser.parseString(input_string.strip(), parseAll)
         if p:
             return p[0]

edtf/parser/tests.py

@@ -347,6 +347,14 @@ def test_non_parsing(bad_input):
         parse(bad_input)
 
 
+@pytest.mark.parametrize("bad_input", [None, ""])
+def test_empty_input(bad_input):
+    """Test that empty input raises a specific exception."""
+    with pytest.raises(EDTFParseException) as exc_info:
+        parse(bad_input)
+    assert "You must supply some input text" in str(exc_info.value)
+
+
 def test_comparisons():
     """Test comparisons between parsed EDTF objects and standard dates."""
     d1 = parse("1979-08~")