Added tests for standalone generator

lark/tools/standalone.py

@@ -167,9 +167,8 @@ class TreeBuilderAtoms:
         print('}')
         print('parse_tree_builder = ParseTreeBuilder(RULES.values(), Tree)')
 
-def main(fn, start):
-    with codecs.open(fn, encoding='utf8') as f:
-        lark_inst = Lark(f, parser="lalr", start=start)
+def main(fobj, start):
+    lark_inst = Lark(fobj, parser="lalr", start=start)
 
     lexer_atoms = LexerAtoms(lark_inst.parser.lexer)
     parser_atoms = ParserAtoms(lark_inst.parser.parser)
@@ -178,9 +177,12 @@ def main(fn, start):
     print('# The file was automatically generated by Lark v%s' % lark.__version__)
 
     for pyfile in EXTRACT_STANDALONE_FILES:
-        print (extract_sections(open(os.path.join(__larkdir__, pyfile)))['standalone'])
+        with open(os.path.join(__larkdir__, pyfile)) as f:
+            print (extract_sections(f)['standalone'])
+
+    with open(os.path.join(__larkdir__, 'grammar.py')) as grammar_py:
+        print(grammar_py.read())
 
-    print(open(os.path.join(__larkdir__, 'grammar.py')).read())
     print('Shift = 0')
     print('Reduce = 1')
     lexer_atoms.print_python()
@@ -200,4 +202,5 @@ if __name__ == '__main__':
     else:
         assert False, sys.argv
 
-    main(fn, start)
+    with codecs.open(fn, encoding='utf8') as f:
+        main(f, start)

tests/__main__.py

@@ -4,6 +4,7 @@ import unittest
 import logging
 
 from .test_trees import TestTrees
+from .test_tools import TestStandalone
 
 try:
     from .test_nearley.test_nearley import TestNearley

tests/test_tools.py

@@ -0,0 +1,50 @@
+from __future__ import absolute_import
+
+import sys
+import unittest
+from unittest import TestCase
+
+from lark.tree import Tree
+
+from lark.tools import standalone
+
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
+class TestStandalone(TestCase):
+    def setUp(self):
+        pass
+
+    def test_simple(self):
+        grammar = """
+            start: NUMBER WORD
+
+            %import common.NUMBER
+            %import common.WORD
+            %import common.WS
+            %ignore WS
+
+        """
+
+        code_buf = StringIO()
+        temp = sys.stdout
+        sys.stdout = code_buf
+        standalone.main(StringIO(grammar), 'start')
+        sys.stdout = temp
+        code = code_buf.getvalue()
+
+        context = {}
+        exec(code, context)
+        _Lark = context['Lark_StandAlone']
+
+        l = _Lark()
+        x = l.parse('12 elephants')
+        self.assertEqual(x.children, ['12', 'elephants'])
+
+
+if __name__ == '__main__':
+    unittest.main()
+
+

tests/test_trees.py

@@ -2,7 +2,6 @@ from __future__ import absolute_import
 
 import unittest
 from unittest import TestCase
-import logging
 import copy
 import pickle