cpython/Lib/test/test_string/_support.py
Miss Islington (bot) 95baa28d9f
[3.14] gh-132661: Add default value (of "") for Interpolation.expression (GH-136441) (#136511)
Co-authored-by: Dave Peck <davepeck@gmail.com>
2025-07-10 14:52:18 +00:00

67 lines
2.3 KiB
Python

import unittest
from string.templatelib import Interpolation
class TStringBaseCase:
def assertInterpolationEqual(self, i, exp):
"""Test Interpolation equality.
The *i* argument must be an Interpolation instance.
The *exp* argument must be a tuple of the form
(value, expression, conversion, format_spec) where the final three
items may be omitted and are assumed to be '', None and '' respectively.
"""
if len(exp) == 4:
actual = (i.value, i.expression, i.conversion, i.format_spec)
self.assertEqual(actual, exp)
elif len(exp) == 3:
self.assertEqual((i.value, i.expression, i.conversion), exp)
self.assertEqual(i.format_spec, "")
elif len(exp) == 2:
self.assertEqual((i.value, i.expression), exp)
self.assertEqual(i.conversion, None)
self.assertEqual(i.format_spec, "")
elif len(exp) == 1:
self.assertEqual((i.value,), exp)
self.assertEqual(i.expression, "")
self.assertEqual(i.conversion, None)
self.assertEqual(i.format_spec, "")
def assertTStringEqual(self, t, strings, interpolations):
"""Test template string literal equality.
The *strings* argument must be a tuple of strings equal to *t.strings*.
The *interpolations* argument must be a sequence of tuples which are
compared against *t.interpolations*. Each tuple must match the form
described in the `assertInterpolationEqual` method.
"""
self.assertEqual(t.strings, strings)
self.assertEqual(len(t.interpolations), len(interpolations))
for i, exp in zip(t.interpolations, interpolations, strict=True):
self.assertInterpolationEqual(i, exp)
def convert(value, conversion):
if conversion == "a":
return ascii(value)
elif conversion == "r":
return repr(value)
elif conversion == "s":
return str(value)
return value
def fstring(template):
parts = []
for item in template:
match item:
case str() as s:
parts.append(s)
case Interpolation(value, _, conversion, format_spec):
value = convert(value, conversion)
value = format(value, format_spec)
parts.append(value)
return "".join(parts)