AnnotationBear: Use unescaped_search_for

Find function doesn't ignore escape sequences
hence we use unescaped_search_for to ignore
the sequences which are escaped.

Fixes coala#993

Author: abh3po

bears/general/AnnotationBear.py

@@ -4,6 +4,7 @@
 from coalib.results.Result import Result, RESULT_SEVERITY
 from coalib.results.SourceRange import SourceRange
 from coalib.results.AbsolutePosition import AbsolutePosition
+from coala_utils.string_processing.Core import unescaped_search_for
 
 
 class AnnotationBear(LocalBear):
@@ -199,10 +200,8 @@ def get_multiline(file,
             A SourceRange object holding the range of the multi-line annotation
             and the end_position of the annotation as an integer.
         """
-        end_start = text.find(annotation_end,
-                              position + 1)
-        end_end = end_start + len(annotation_end) - 1
-        if end_start == -1:
+        end_end = get_end_position(annotation_end, text, position)
+        if end_end == -1:
             _range = SourceRange.from_absolute_position(
                 filename,
                 AbsolutePosition(file, position))
@@ -238,9 +237,8 @@ def get_singleline_strings(file,
             A SourceRange object identifying the range of the single-line
             string and the end_position of the string as an integer.
         """
-        end_position = (text.find(string_end, position + 1)
-                        + len(string_end) - 1)
-        newline = text.find("\n", position + 1)
+        end_position = get_end_position(string_end, text, position)
+        newline = get_end_position("\n", text, position)
         if newline == -1:
             newline = len(text)
         if end_position == -1:
@@ -273,7 +271,7 @@ def get_singleline_comment(file, filename, text, comment, position):
             A SourceRange object identifying the range of the single-line
             comment and the end_position of the comment as an integer.
         """
-        end_position = text.find("\n", position + 1)
+        end_position = get_end_position("\n", text, position)
         if end_position == -1:
             end_position = len(text) - 1
         return (SourceRange.from_absolute_position(
@@ -283,6 +281,16 @@ def get_singleline_comment(file, filename, text, comment, position):
                 end_position)
 
 
+def get_end_position(end_marker, text, position):
+    try:
+        end_match = next(unescaped_search_for(end_marker, text[position + 1:]))
+        end_position = position + end_match.span()[1]
+    except StopIteration:
+        end_position = -1
+
+    return end_position
+
+
 class NoCloseError(Exception):
 
     def __init__(self, annotation, code):

tests/general/AnnotationBearTest.py

@@ -140,3 +140,13 @@ def test_no_coalang(self):
         with execute_bear(uut, "F", text) as result:
             self.assertEqual(result[0].contents,
                              "coalang specification for Valyrian not found.")
+
+    def test_escape_strings(self):
+        text = [r"'I\'ll be back' -T1000"]
+        uut = AnnotationBear(self.section1, Queue())
+        test_range = SourceRange.from_absolute_position(
+            "F",
+            AbsolutePosition(text, 0),
+            AbsolutePosition(text, text[0].find("'", 4)))
+        with execute_bear(uut, "F", text) as result:
+            self.assertEqual(result[0].contents["strings"], (test_range,))