Test for default semantic action

tests/unit/test_default_semantic_action.py

+# -*- coding: utf-8 -*-
+#######################################################################
+# Name: test_default_semantic_action
+# Purpose: Default semantic action is applied during semantic analysis
+#           if no action is given for node type. Default action converts
+#           terminals to strings, remove StrMatch terminals from sequences.
+# Author: Igor R. Dejanović <igor DOT dejanovic AT gmail DOT com>
+# Copyright: (c) 2014 Igor R. Dejanović <igor DOT dejanovic AT gmail DOT com>
+# License: MIT License
+#######################################################################
+import pytest
+from arpeggio import ParserPython, SemanticAction, ParseTreeNode
+from arpeggio import RegExMatch as _
+
+def grammar():      return parentheses, 'strmatch'
+def parentheses():  return '(', rulea, ')'
+def rulea():        return ['+', '-'], number
+def number():       return _(r'\d+')
+
+p_removed = False
+number_str = False
+parse_tree_node = False
+
+class ParenthesesSA(SemanticAction):
+    def first_pass(self, parser, node, children):
+        global p_removed, parse_tree_node
+        p_removed = str(children[0]) != '('
+        parse_tree_node = isinstance(children[0], ParseTreeNode)
+        return children[0] if len(children)==1 else children[1]
+
+
+class RuleSA(SemanticAction):
+    def first_pass(self, parser, node, children):
+        global number_str
+        number_str = type(children[1]) == str
+        return children[1]
+
+
+parentheses.sem = ParenthesesSA()
+rulea.sem = RuleSA()
+
+def test_default_action_enabled():
+
+    parser = ParserPython(grammar)
+
+    parse_tree = parser.parse('(-34) strmatch')
+
+    parser.getASG(defaults=True)
+
+    assert p_removed
+    assert number_str
+    assert not parse_tree_node
+
+
+def test_default_action_disabled():
+
+    parser = ParserPython(grammar)
+
+    parse_tree = parser.parse('(-34) strmatch')
+
+    parser.getASG(defaults=False)
+
+    assert not p_removed
+    assert not number_str
+    assert parse_tree_node
+
+
+