From 9d2ce4bcd4c1763ee0ce7451bda123864d4976b6 Mon Sep 17 00:00:00 2001
From: Dave Halter <davidhalter88@gmail.com>
Date: Fri, 6 Apr 2018 09:50:07 +0200
Subject: [PATCH] Fix a few fstring error gatherings

---
 parso/python/errors.py     | 20 +++++++++++++++++++-
 parso/python/grammar36.txt |  2 +-
 parso/python/tokenize.py   |  2 +-
 test/failing_examples.py   |  2 +-
 test/test_python_errors.py | 14 ++++++++++++++
 5 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/parso/python/errors.py b/parso/python/errors.py
index fe1e273..8dc99b7 100644
--- a/parso/python/errors.py
+++ b/parso/python/errors.py
@@ -843,7 +843,7 @@ class _TryStmtRule(SyntaxRule):
                 self.add_issue(default_except, message=self.message)
 
 
-@ErrorFinder.register_rule(type='string')
+@ErrorFinder.register_rule(type='fstring')
 class _FStringRule(SyntaxRule):
     _fstring_grammar = None
     message_empty = "f-string: empty expression not allowed"  # f'{}'
@@ -864,7 +864,25 @@ class _FStringRule(SyntaxRule):
             cls._fstring_grammar = parso.load_grammar(language='python-f-string')
         return cls._fstring_grammar
 
+    def _check_type(self, fstring_string):
+        index = -1
+        value = fstring_string.value
+        while True:
+            index = value.find('}', index + 1)
+            if index == -1:
+                break  # No further } found, we're finished.
+            elif index + 1 != len(value) and value[index + 1]:
+                # It's }}, which is totally ok.
+                index += 1
+            else:
+                self.add_issue(fstring_string, message=self.message_single_closing)
+
     def is_issue(self, fstring):
+        for fstring_content in fstring.children[1:-1]:
+            if fstring_content.type == 'fstring_string':
+                self._check_type(fstring_content)
+        return
+        print(fstring)
         if 'f' not in fstring.string_prefix.lower():
             return
 
diff --git a/parso/python/grammar36.txt b/parso/python/grammar36.txt
index 7d112f7..b82c1fe 100644
--- a/parso/python/grammar36.txt
+++ b/parso/python/grammar36.txt
@@ -153,5 +153,5 @@ strings: (STRING | fstring)+
 fstring: FSTRING_START fstring_content* FSTRING_END
 fstring_content: FSTRING_STRING | fstring_expr
 fstring_conversion: '!' NAME
-fstring_expr: '{' testlist [ fstring_conversion ] [ fstring_format_spec ] '}'
+fstring_expr: '{' testlist_comp [ fstring_conversion ] [ fstring_format_spec ] '}'
 fstring_format_spec: ':' fstring_content*
diff --git a/parso/python/tokenize.py b/parso/python/tokenize.py
index 150f72a..a410287 100644
--- a/parso/python/tokenize.py
+++ b/parso/python/tokenize.py
@@ -166,7 +166,7 @@ def _create_token_collection(version_info):
     # Because of leftmost-then-longest match semantics, be sure to put the
     # longest operators first (e.g., if = came before ==, == would get
     # recognized as two instances of =).
-    Operator = group(r"\*\*=?", r">>=?", r"<<=?", r"!=",
+    Operator = group(r"\*\*=?", r">>=?", r"<<=?",
                      r"//=?", r"->",
                      r"[+\-*/%&@`|^=<>]=?",
                      r"~")
diff --git a/test/failing_examples.py b/test/failing_examples.py
index 4227679..25e93ca 100644
--- a/test/failing_examples.py
+++ b/test/failing_examples.py
@@ -141,7 +141,7 @@ FAILING_EXAMPLES = [
 
     # f-strings
     'f"{}"',
-    'f"{\\}"',
+    r'f"{\}"',
     'f"{\'\\\'}"',
     'f"{#}"',
     "f'{1!b}'",
diff --git a/test/test_python_errors.py b/test/test_python_errors.py
index b724a41..ca7be7f 100644
--- a/test/test_python_errors.py
+++ b/test/test_python_errors.py
@@ -114,6 +114,20 @@ def _get_actual_exception(code):
         # Python 3.4/3.4 have a bit of a different warning than 3.5/3.6 in
         # certain places. But in others this error makes sense.
         return [wanted, "SyntaxError: can't use starred expression here"], line_nr
+    elif wanted == 'SyntaxError: f-string: unterminated string':
+        wanted = 'SyntaxError: EOL while scanning string literal'
+    elif wanted == 'SyntaxError: f-string expression part cannot include a backslash':
+        return [
+            wanted,
+            "SyntaxError: EOL while scanning string literal",
+            "SyntaxError: unexpected character after line continuation character",
+        ], line_nr
+    elif wanted == 'SyntaxError: f-string: empty expression not allowed':
+        wanted = 'SyntaxError: invalid syntax'
+    elif wanted == "SyntaxError: f-string expression part cannot include '#'":
+        wanted = 'SyntaxError: invalid syntax'
+    elif wanted == "SyntaxError: f-string: expecting '}'":
+        wanted = 'SyntaxError: EOL while scanning string literal'
     return [wanted], line_nr