Modify test conversions to fix failing tests (#194)

we-like-parsers · Oct 31, 2022 · de6ac55 · de6ac55
1 parent 947d210
commit de6ac55
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diff --git a/Grammar/python.gram b/Grammar/python.gram
@@ -852,16 +852,17 @@ lambda_param[arg_ty]: a=NAME { _PyAST_arg(a->v.Name.id, NULL, NULL, EXTRA) }
 # LITERALS
 # ========
 
+gstring_conversion[expr_ty]:
+    | "!" conv=NAME { conv }
+    | "!" !NAME { RAISE_SYNTAX_ERROR("f-string: invalid conversion character: expected 's', 'r', or 'a'") }
 gstring_middle[expr_ty]:
     | gstring_replacement_field
     | t=FSTRING_MIDDLE { _PyPegen_constant_from_token2(p, t) }
 # There are some shenanigans with the gstring_format_spec: Don't try to put it in its own rule
 # or otherwise it will try to parse the first token with the regular tokenizer mode (due to the EXTRA).
 # TODO: (Ideally we need a way similar to 'memo' so the parser can set the tokenize mode on fstring/normal)
 gstring_replacement_field[expr_ty]:
-    | expr_start='{' a=(yield_expr | star_expressions) debug_expr="="? conversion=[
-        "!" conv=NAME {conv}
-    ] format=[
+    | expr_start='{' a=(yield_expr | star_expressions) debug_expr="="? conversion=[gstring_conversion] format=[
         ':' spec=gstring_format_spec* { spec ? _PyAST_JoinedStr((asdl_expr_seq*)spec, EXTRA) : NULL }
     ] &&'}' {
         _PyPegen_formatted_value(p, a, debug_expr, conversion, format, EXTRA)

diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py
@@ -993,16 +993,14 @@ def test_conversions(self):
                              "f'{3!G}'",
                              "f'{3!!}'",
                              "f'{3!:}'",
-                             "f'{3! s}'",  # no space before conversion char
-                             ])
-
-        self.assertAllRaise(SyntaxError, "f-string: expecting '}'",
-                            ["f'{x!s{y}}'",
                              "f'{3!ss}'",
                              "f'{3!ss:}'",
                              "f'{3!ss:s}'",
                              ])
 
+        with self.assertRaisesRegex(SyntaxError, "expected '}'"):
+            eval("f'{x!s{y}}'")
+
     def test_assignment(self):
         self.assertAllRaise(SyntaxError, r'invalid syntax',
                             ["f'' = 3",