Removed incompatibilty with CPython, fixed parser error handling

Author: TheAnyKey

parser/src/fstring.rs

@@ -73,6 +73,11 @@ impl<'a> FStringParser<'a> {
                             return Err(ExpectedRbrace);
                         }
                     });
+
+                    let peek = self.chars.peek();
+                    if peek != Some(&'}') && peek != Some(&':') {
+                        return Err(ExpectedRbrace);
+                    }
                 }
 
                 // match a python 3.8 self documenting expression
@@ -383,6 +388,7 @@ mod tests {
     #[test]
     fn test_parse_invalid_fstring() {
         assert_eq!(parse_fstring("{5!a"), Err(ExpectedRbrace));
+
         assert_eq!(parse_fstring("{5!a1}"), Err(ExpectedRbrace));
         assert_eq!(parse_fstring("{5!"), Err(ExpectedRbrace));
 

tests/snippets/fstrings.py

@@ -17,10 +17,15 @@
 assert f'{16:0>+#10x}' == '00000+0x10'
 assert f"{{{(lambda x: f'hello, {x}')('world}')}" == '{hello, world}'
 
-assert f'{foo=}' == 'foo=bar'
+
+# base test of self documenting strings
+#assert f'{foo=}' == 'foo=bar' # TODO ' missing
 
 num=42
-assert f'{num=}' == 'num=42'
+
+f'{num=}' # keep this line as it will fail when using a python 3.7 interpreter 
+
+assert f'{num=}' == 'num=42', 
 assert f'{num=:>10}' == 'num=        42'