Add assertTStringEqual() helper

Lib/test/test_string/_support.py

@@ -1,6 +1,37 @@
+import unittest
 from string.templatelib import Interpolation
 
 
+class TStringTestCase(unittest.TestCase):
+    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 consists of
+        (value, expression, conversion, format_spec), though the final two
+        items may be omitted, and are assumed to be None and '' respectively.
+        """
+        self.assertEqual(t.strings, strings)
+        self.assertEqual(len(t.interpolations), len(interpolations))
+
+        for i, exp in zip(t.interpolations, interpolations, strict=True):
+            if len(exp) == 4:
+                actual = (i.value, i.expression, i.conversion, i.format_spec)
+                self.assertEqual(actual, exp)
+                continue
+
+            if len(exp) == 3:
+                self.assertEqual((i.value, i.expression, i.conversion),  exp)
+                self.assertEqual(i.format_spec, '')
+                continue
+
+            self.assertEqual((i.value, i.expression), exp)
+            self.assertEqual(i.format_spec, '')
+            self.assertIsNone(i.conversion)
+
+
 def convert(value, conversion):
     if conversion == "a":
         return ascii(value)

Lib/test/test_string/test_templatelib.py

@@ -1,78 +1,55 @@
-import unittest
 from string.templatelib import Template, Interpolation
 
-from test.test_string._support import f
+from test.test_string._support import TStringTestCase, f
 
 
-class TestTemplate(unittest.TestCase):
+class TestTemplate(TStringTestCase):
 
     def test_basic_creation(self):
         # Simple t-string creation
-        t = t"Hello, world"
-        self.assertTrue(isinstance(t, Template))
-        self.assertEqual(t.strings, ("Hello, world",))
-        self.assertEqual(len(t.interpolations), 0)
-        self.assertEqual(f(t), "Hello, world")
+        t = t'Hello, world'
+        self.assertIsInstance(t, Template)
+        self.assertTStringEqual(t, ('Hello, world',), ())
+        self.assertEqual(f(t), 'Hello, world')
 
         # Empty t-string
-        t = t""
-        self.assertEqual(t.strings, ("",))
-        self.assertEqual(len(t.interpolations), 0)
-        self.assertEqual(f(t), "")
+        t = t''
+        self.assertTStringEqual(t, ('',), ())
+        self.assertEqual(f(t), '')
 
         # Multi-line t-string
         t = t"""Hello,
 world"""
-        self.assertEqual(t.strings, ("Hello,\nworld",))
+        self.assertEqual(t.strings, ('Hello,\nworld',))
         self.assertEqual(len(t.interpolations), 0)
-        self.assertEqual(f(t), "Hello,\nworld")
+        self.assertEqual(f(t), 'Hello,\nworld')
 
     def test_creation_interleaving(self):
         # Should add strings on either side
-        t = Template(Interpolation("Maria", "name", None, ""))
-        self.assertEqual(t.strings, ("", ""))
-        self.assertEqual(t.interpolations[0].value, "Maria")
-        self.assertEqual(t.interpolations[0].expression, "name")
-        self.assertEqual(t.interpolations[0].conversion, None)
-        self.assertEqual(t.interpolations[0].format_spec, "")
-        self.assertEqual(f(t), "Maria")
+        t = Template(Interpolation('Maria', 'name', None, ''))
+        self.assertTStringEqual(t, ('', ''), [('Maria', 'name')])
+        self.assertEqual(f(t), 'Maria')
 
         # Should prepend empty string
-        t = Template(Interpolation("Maria", "name", None, ""), " is my name")
-        self.assertEqual(t.strings, ("", " is my name"))
-        self.assertEqual(t.interpolations[0].value, "Maria")
-        self.assertEqual(t.interpolations[0].expression, "name")
-        self.assertEqual(t.interpolations[0].conversion, None)
-        self.assertEqual(t.interpolations[0].format_spec, "")
-        self.assertEqual(f(t), "Maria is my name")
+        t = Template(Interpolation('Maria', 'name', None, ''), ' is my name')
+        self.assertTStringEqual(t, ('', ' is my name'), [('Maria', 'name')])
+        self.assertEqual(f(t), 'Maria is my name')
 
         # Should append empty string
-        t = Template("Hello, ", Interpolation("Maria", "name", None, ""))
-        self.assertEqual(t.strings, ("Hello, ", ""))
-        self.assertEqual(t.interpolations[0].value, "Maria")
-        self.assertEqual(t.interpolations[0].expression, "name")
-        self.assertEqual(t.interpolations[0].conversion, None)
-        self.assertEqual(t.interpolations[0].format_spec, "")
-        self.assertEqual(f(t), "Hello, Maria")
+        t = Template('Hello, ', Interpolation('Maria', 'name', None, ''))
+        self.assertTStringEqual(t, ('Hello, ', ''), [('Maria', 'name')])
+        self.assertEqual(f(t), 'Hello, Maria')
 
         # Should concatenate strings
-        t = Template("Hello", ", ", Interpolation("Maria", "name", None, ""), "!")
-        self.assertEqual(t.strings, ("Hello, ", "!"))
-        self.assertEqual(t.interpolations[0].value, "Maria")
-        self.assertEqual(t.interpolations[0].expression, "name")
-        self.assertEqual(t.interpolations[0].conversion, None)
-        self.assertEqual(t.interpolations[0].format_spec, "")
-        self.assertEqual(f(t), "Hello, Maria!")
+        t = Template('Hello', ', ', Interpolation('Maria', 'name', None, ''),
+                     '!')
+        self.assertTStringEqual(t, ('Hello, ', '!'), [('Maria', 'name')])
+        self.assertEqual(f(t), 'Hello, Maria!')
 
         # Should add strings on either side and in between
-        t = Template(Interpolation("Maria", "name", None, ""), Interpolation("Python", "language", None, ""))
-        self.assertEqual(t.strings, ("", "", ""))
-        self.assertEqual(t.interpolations[0].value, "Maria")
-        self.assertEqual(t.interpolations[0].expression, "name")
-        self.assertEqual(t.interpolations[0].conversion, None)
-        self.assertEqual(t.interpolations[0].format_spec, "")
-        self.assertEqual(t.interpolations[1].value, "Python")
-        self.assertEqual(t.interpolations[1].expression, "language")
-        self.assertEqual(t.interpolations[1].conversion, None)
-        self.assertEqual(t.interpolations[1].format_spec, "")
-        self.assertEqual(f(t), "MariaPython")
+        t = Template(Interpolation('Maria', 'name', None, ''),
+                     Interpolation('Python', 'language', None, ''))
+        self.assertTStringEqual(
+            t, ('', '', ''), [('Maria', 'name'), ('Python', 'language')]
+        )
+        self.assertEqual(f(t), 'MariaPython')