Merge pull request #344 from chisholm/fix_ast_builder

Fix the pattern AST creation function

stix2/pattern_visitor.py

@@ -1,16 +1,12 @@
 import importlib
 import inspect
 
-from antlr4 import CommonTokenStream, InputStream
-from antlr4.tree.Trees import Trees
-import six
 from stix2patterns.exceptions import ParseException
-from stix2patterns.grammars.STIXPatternLexer import STIXPatternLexer
 from stix2patterns.grammars.STIXPatternParser import (
     STIXPatternParser, TerminalNode,
 )
 from stix2patterns.grammars.STIXPatternVisitor import STIXPatternVisitor
-from stix2patterns.validator import STIXPatternErrorListener
+from stix2patterns.v20.pattern import Pattern
 
 from .patterns import *
 from .patterns import _BooleanExpression
@@ -328,41 +324,9 @@ class STIXPatternVisitorForSTIX2(STIXPatternVisitor):
 
 def create_pattern_object(pattern, module_suffix="", module_name=""):
     """
-    Validates a pattern against the STIX Pattern grammar.  Error messages are
-    returned in a list.  The test passed if the returned list is empty.
+    Create a STIX pattern AST from a pattern string.
     """
 
-    start = ''
-    if isinstance(pattern, six.string_types):
-        start = pattern[:2]
-        pattern = InputStream(pattern)
-
-    if not start:
-        start = pattern.readline()[:2]
-        pattern.seek(0)
-
-    parseErrListener = STIXPatternErrorListener()
-
-    lexer = STIXPatternLexer(pattern)
-    # it always adds a console listener by default... remove it.
-    lexer.removeErrorListeners()
-
-    stream = CommonTokenStream(lexer)
-
-    parser = STIXPatternParser(stream)
-
-    parser.buildParseTrees = True
-    # it always adds a console listener by default... remove it.
-    parser.removeErrorListeners()
-    parser.addErrorListener(parseErrListener)
-
-    # To improve error messages, replace "<INVALID>" in the literal
-    # names with symbolic names.  This is a hack, but seemed like
-    # the simplest workaround.
-    for i, lit_name in enumerate(parser.literalNames):
-        if lit_name == u"<INVALID>":
-            parser.literalNames[i] = parser.symbolicNames[i]
-
-    tree = parser.pattern()
+    pattern_obj = Pattern(pattern)
     builder = STIXPatternVisitorForSTIX2(module_suffix, module_name)
-    return builder.visit(tree)
+    return pattern_obj.visit(builder)

stix2/test/v21/test_indicator.py

@@ -271,7 +271,7 @@ def test_indicator_stix20_invalid_pattern():
         )
 
     assert excinfo.value.cls == stix2.v21.Indicator
-    assert "FAIL: The same qualifier is used more than once" in str(excinfo.value)
+    assert "FAIL: Duplicate qualifier type encountered" in str(excinfo.value)
 
     ind = stix2.v21.Indicator(
         type="indicator",

stix2/test/v21/test_pattern_expressions.py

@@ -1,6 +1,7 @@
 import datetime
 
 import pytest
+from stix2patterns.exceptions import ParseException
 
 import stix2
 from stix2.pattern_visitor import create_pattern_object
@@ -515,3 +516,8 @@ def test_list_constant():
 def test_parsing_multiple_slashes_quotes():
     patt_obj = create_pattern_object("[ file:name = 'weird_name\\'' ]")
     assert str(patt_obj) == "[file:name = 'weird_name\\'']"
+
+
+def test_parse_error():
+    with pytest.raises(ParseException):
+        create_pattern_object("[ file: name = 'weirdname]")