1 """Unit tests for the positional only argument syntax specified in PEP 570."""
2
3 import dis
4 import pickle
5 import unittest
6
7 from test.support import check_syntax_error
8
9
10 def global_pos_only_f(a, b, /):
11 return a, b
12
13 def global_pos_only_and_normal(a, /, b):
14 return a, b
15
16 def global_pos_only_defaults(a=1, /, b=2):
17 return a, b
18
19 class ESC[4;38;5;81mPositionalOnlyTestCase(ESC[4;38;5;149munittestESC[4;38;5;149m.ESC[4;38;5;149mTestCase):
20
21 def assertRaisesSyntaxError(self, codestr, regex="invalid syntax"):
22 with self.assertRaisesRegex(SyntaxError, regex):
23 compile(codestr + "\n", "<test>", "single")
24
25 def test_invalid_syntax_errors(self):
26 check_syntax_error(self, "def f(a, b = 5, /, c): pass", "parameter without a default follows parameter with a default")
27 check_syntax_error(self, "def f(a = 5, b, /, c): pass", "parameter without a default follows parameter with a default")
28 check_syntax_error(self, "def f(a = 5, b=1, /, c, *, d=2): pass", "parameter without a default follows parameter with a default")
29 check_syntax_error(self, "def f(a = 5, b, /): pass", "parameter without a default follows parameter with a default")
30 check_syntax_error(self, "def f(a, /, b = 5, c): pass", "parameter without a default follows parameter with a default")
31 check_syntax_error(self, "def f(*args, /): pass")
32 check_syntax_error(self, "def f(*args, a, /): pass")
33 check_syntax_error(self, "def f(**kwargs, /): pass")
34 check_syntax_error(self, "def f(/, a = 1): pass")
35 check_syntax_error(self, "def f(/, a): pass")
36 check_syntax_error(self, "def f(/): pass")
37 check_syntax_error(self, "def f(*, a, /): pass")
38 check_syntax_error(self, "def f(*, /, a): pass")
39 check_syntax_error(self, "def f(a, /, a): pass", "duplicate argument 'a' in function definition")
40 check_syntax_error(self, "def f(a, /, *, a): pass", "duplicate argument 'a' in function definition")
41 check_syntax_error(self, "def f(a, b/2, c): pass")
42 check_syntax_error(self, "def f(a, /, c, /): pass")
43 check_syntax_error(self, "def f(a, /, c, /, d): pass")
44 check_syntax_error(self, "def f(a, /, c, /, d, *, e): pass")
45 check_syntax_error(self, "def f(a, *, c, /, d, e): pass")
46
47 def test_invalid_syntax_errors_async(self):
48 check_syntax_error(self, "async def f(a, b = 5, /, c): pass", "parameter without a default follows parameter with a default")
49 check_syntax_error(self, "async def f(a = 5, b, /, c): pass", "parameter without a default follows parameter with a default")
50 check_syntax_error(self, "async def f(a = 5, b=1, /, c, d=2): pass", "parameter without a default follows parameter with a default")
51 check_syntax_error(self, "async def f(a = 5, b, /): pass", "parameter without a default follows parameter with a default")
52 check_syntax_error(self, "async def f(a, /, b = 5, c): pass", "parameter without a default follows parameter with a default")
53 check_syntax_error(self, "async def f(*args, /): pass")
54 check_syntax_error(self, "async def f(*args, a, /): pass")
55 check_syntax_error(self, "async def f(**kwargs, /): pass")
56 check_syntax_error(self, "async def f(/, a = 1): pass")
57 check_syntax_error(self, "async def f(/, a): pass")
58 check_syntax_error(self, "async def f(/): pass")
59 check_syntax_error(self, "async def f(*, a, /): pass")
60 check_syntax_error(self, "async def f(*, /, a): pass")
61 check_syntax_error(self, "async def f(a, /, a): pass", "duplicate argument 'a' in function definition")
62 check_syntax_error(self, "async def f(a, /, *, a): pass", "duplicate argument 'a' in function definition")
63 check_syntax_error(self, "async def f(a, b/2, c): pass")
64 check_syntax_error(self, "async def f(a, /, c, /): pass")
65 check_syntax_error(self, "async def f(a, /, c, /, d): pass")
66 check_syntax_error(self, "async def f(a, /, c, /, d, *, e): pass")
67 check_syntax_error(self, "async def f(a, *, c, /, d, e): pass")
68
69 def test_optional_positional_only_args(self):
70 def f(a, b=10, /, c=100):
71 return a + b + c
72
73 self.assertEqual(f(1, 2, 3), 6)
74 self.assertEqual(f(1, 2, c=3), 6)
75 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
76 f(1, b=2, c=3)
77
78 self.assertEqual(f(1, 2), 103)
79 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
80 f(1, b=2)
81 self.assertEqual(f(1, c=2), 13)
82
83 def f(a=1, b=10, /, c=100):
84 return a + b + c
85
86 self.assertEqual(f(1, 2, 3), 6)
87 self.assertEqual(f(1, 2, c=3), 6)
88 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
89 f(1, b=2, c=3)
90
91 self.assertEqual(f(1, 2), 103)
92 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"):
93 f(1, b=2)
94 self.assertEqual(f(1, c=2), 13)
95
96 def test_syntax_for_many_positional_only(self):
97 # more than 255 positional only arguments, should compile ok
98 fundef = "def f(%s, /):\n pass\n" % ', '.join('i%d' % i for i in range(300))
99 compile(fundef, "<test>", "single")
100
101 def test_pos_only_definition(self):
102 def f(a, b, c, /, d, e=1, *, f, g=2):
103 pass
104
105 self.assertEqual(5, f.__code__.co_argcount) # 3 posonly + 2 "standard args"
106 self.assertEqual(3, f.__code__.co_posonlyargcount)
107 self.assertEqual((1,), f.__defaults__)
108
109 def f(a, b, c=1, /, d=2, e=3, *, f, g=4):
110 pass
111
112 self.assertEqual(5, f.__code__.co_argcount) # 3 posonly + 2 "standard args"
113 self.assertEqual(3, f.__code__.co_posonlyargcount)
114 self.assertEqual((1, 2, 3), f.__defaults__)
115
116 def test_pos_only_call_via_unpacking(self):
117 def f(a, b, /):
118 return a + b
119
120 self.assertEqual(f(*[1, 2]), 3)
121
122 def test_use_positional_as_keyword(self):
123 def f(a, /):
124 pass
125 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"
126 with self.assertRaisesRegex(TypeError, expected):
127 f(a=1)
128
129 def f(a, /, b):
130 pass
131 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"
132 with self.assertRaisesRegex(TypeError, expected):
133 f(a=1, b=2)
134
135 def f(a, b, /):
136 pass
137 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'a, b'"
138 with self.assertRaisesRegex(TypeError, expected):
139 f(a=1, b=2)
140
141 def test_positional_only_and_arg_invalid_calls(self):
142 def f(a, b, /, c):
143 pass
144 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'c'"):
145 f(1, 2)
146 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'b' and 'c'"):
147 f(1)
148 with self.assertRaisesRegex(TypeError, r"f\(\) missing 3 required positional arguments: 'a', 'b', and 'c'"):
149 f()
150 with self.assertRaisesRegex(TypeError, r"f\(\) takes 3 positional arguments but 4 were given"):
151 f(1, 2, 3, 4)
152
153 def test_positional_only_and_optional_arg_invalid_calls(self):
154 def f(a, b, /, c=3):
155 pass
156 f(1, 2) # does not raise
157 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'b'"):
158 f(1)
159 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"):
160 f()
161 with self.assertRaisesRegex(TypeError, r"f\(\) takes from 2 to 3 positional arguments but 4 were given"):
162 f(1, 2, 3, 4)
163
164 def test_positional_only_and_kwonlyargs_invalid_calls(self):
165 def f(a, b, /, c, *, d, e):
166 pass
167 f(1, 2, 3, d=1, e=2) # does not raise
168 with self.assertRaisesRegex(TypeError, r"missing 1 required keyword-only argument: 'd'"):
169 f(1, 2, 3, e=2)
170 with self.assertRaisesRegex(TypeError, r"missing 2 required keyword-only arguments: 'd' and 'e'"):
171 f(1, 2, 3)
172 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'c'"):
173 f(1, 2)
174 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'b' and 'c'"):
175 f(1)
176 with self.assertRaisesRegex(TypeError, r" missing 3 required positional arguments: 'a', 'b', and 'c'"):
177 f()
178 with self.assertRaisesRegex(TypeError, r"f\(\) takes 3 positional arguments but 6 positional arguments "
179 r"\(and 2 keyword-only arguments\) were given"):
180 f(1, 2, 3, 4, 5, 6, d=7, e=8)
181 with self.assertRaisesRegex(TypeError, r"f\(\) got an unexpected keyword argument 'f'"):
182 f(1, 2, 3, d=1, e=4, f=56)
183
184 def test_positional_only_invalid_calls(self):
185 def f(a, b, /):
186 pass
187 f(1, 2) # does not raise
188 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'b'"):
189 f(1)
190 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"):
191 f()
192 with self.assertRaisesRegex(TypeError, r"f\(\) takes 2 positional arguments but 3 were given"):
193 f(1, 2, 3)
194
195 def test_positional_only_with_optional_invalid_calls(self):
196 def f(a, b=2, /):
197 pass
198 f(1) # does not raise
199 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'a'"):
200 f()
201
202 with self.assertRaisesRegex(TypeError, r"f\(\) takes from 1 to 2 positional arguments but 3 were given"):
203 f(1, 2, 3)
204
205 def test_no_standard_args_usage(self):
206 def f(a, b, /, *, c):
207 pass
208
209 f(1, 2, c=3)
210 with self.assertRaises(TypeError):
211 f(1, b=2, c=3)
212
213 def test_change_default_pos_only(self):
214 def f(a, b=2, /, c=3):
215 return a + b + c
216
217 self.assertEqual((2,3), f.__defaults__)
218 f.__defaults__ = (1, 2, 3)
219 self.assertEqual(f(1, 2, 3), 6)
220
221 def test_lambdas(self):
222 x = lambda a, /, b: a + b
223 self.assertEqual(x(1,2), 3)
224 self.assertEqual(x(1,b=2), 3)
225
226 x = lambda a, /, b=2: a + b
227 self.assertEqual(x(1), 3)
228
229 x = lambda a, b, /: a + b
230 self.assertEqual(x(1, 2), 3)
231
232 x = lambda a, b, /, : a + b
233 self.assertEqual(x(1, 2), 3)
234
235 def test_invalid_syntax_lambda(self):
236 check_syntax_error(self, "lambda a, b = 5, /, c: None", "parameter without a default follows parameter with a default")
237 check_syntax_error(self, "lambda a = 5, b, /, c: None", "parameter without a default follows parameter with a default")
238 check_syntax_error(self, "lambda a = 5, b=1, /, c, *, d=2: None", "parameter without a default follows parameter with a default")
239 check_syntax_error(self, "lambda a = 5, b, /: None", "parameter without a default follows parameter with a default")
240 check_syntax_error(self, "lambda a, /, b = 5, c: None", "parameter without a default follows parameter with a default")
241 check_syntax_error(self, "lambda *args, /: None")
242 check_syntax_error(self, "lambda *args, a, /: None")
243 check_syntax_error(self, "lambda **kwargs, /: None")
244 check_syntax_error(self, "lambda /, a = 1: None")
245 check_syntax_error(self, "lambda /, a: None")
246 check_syntax_error(self, "lambda /: None")
247 check_syntax_error(self, "lambda *, a, /: None")
248 check_syntax_error(self, "lambda *, /, a: None")
249 check_syntax_error(self, "lambda a, /, a: None", "duplicate argument 'a' in function definition")
250 check_syntax_error(self, "lambda a, /, *, a: None", "duplicate argument 'a' in function definition")
251 check_syntax_error(self, "lambda a, /, b, /: None")
252 check_syntax_error(self, "lambda a, /, b, /, c: None")
253 check_syntax_error(self, "lambda a, /, b, /, c, *, d: None")
254 check_syntax_error(self, "lambda a, *, b, /, c: None")
255
256 def test_posonly_methods(self):
257 class ESC[4;38;5;81mExample:
258 def f(self, a, b, /):
259 return a, b
260
261 self.assertEqual(Example().f(1, 2), (1, 2))
262 self.assertEqual(Example.f(Example(), 1, 2), (1, 2))
263 self.assertRaises(TypeError, Example.f, 1, 2)
264 expected = r"f\(\) got some positional-only arguments passed as keyword arguments: 'b'"
265 with self.assertRaisesRegex(TypeError, expected):
266 Example().f(1, b=2)
267
268 def test_module_function(self):
269 with self.assertRaisesRegex(TypeError, r"f\(\) missing 2 required positional arguments: 'a' and 'b'"):
270 global_pos_only_f()
271
272
273 def test_closures(self):
274 def f(x,y):
275 def g(x2,/,y2):
276 return x + y + x2 + y2
277 return g
278
279 self.assertEqual(f(1,2)(3,4), 10)
280 with self.assertRaisesRegex(TypeError, r"g\(\) missing 1 required positional argument: 'y2'"):
281 f(1,2)(3)
282 with self.assertRaisesRegex(TypeError, r"g\(\) takes 2 positional arguments but 3 were given"):
283 f(1,2)(3,4,5)
284
285 def f(x,/,y):
286 def g(x2,y2):
287 return x + y + x2 + y2
288 return g
289
290 self.assertEqual(f(1,2)(3,4), 10)
291
292 def f(x,/,y):
293 def g(x2,/,y2):
294 return x + y + x2 + y2
295 return g
296
297 self.assertEqual(f(1,2)(3,4), 10)
298 with self.assertRaisesRegex(TypeError, r"g\(\) missing 1 required positional argument: 'y2'"):
299 f(1,2)(3)
300 with self.assertRaisesRegex(TypeError, r"g\(\) takes 2 positional arguments but 3 were given"):
301 f(1,2)(3,4,5)
302
303 def test_annotations_in_closures(self):
304
305 def inner_has_pos_only():
306 def f(x: int, /): ...
307 return f
308
309 assert inner_has_pos_only().__annotations__ == {'x': int}
310
311 class ESC[4;38;5;81mSomething:
312 def method(self):
313 def f(x: int, /): ...
314 return f
315
316 assert Something().method().__annotations__ == {'x': int}
317
318 def multiple_levels():
319 def inner_has_pos_only():
320 def f(x: int, /): ...
321 return f
322 return inner_has_pos_only()
323
324 assert multiple_levels().__annotations__ == {'x': int}
325
326 def test_same_keyword_as_positional_with_kwargs(self):
327 def f(something,/,**kwargs):
328 return (something, kwargs)
329
330 self.assertEqual(f(42, something=42), (42, {'something': 42}))
331
332 with self.assertRaisesRegex(TypeError, r"f\(\) missing 1 required positional argument: 'something'"):
333 f(something=42)
334
335 self.assertEqual(f(42), (42, {}))
336
337 def test_mangling(self):
338 class ESC[4;38;5;81mX:
339 def f(self, __a=42, /):
340 return __a
341
342 def f2(self, __a=42, /, __b=43):
343 return (__a, __b)
344
345 def f3(self, __a=42, /, __b=43, *, __c=44):
346 return (__a, __b, __c)
347
348 self.assertEqual(X().f(), 42)
349 self.assertEqual(X().f2(), (42, 43))
350 self.assertEqual(X().f3(), (42, 43, 44))
351
352 def test_too_many_arguments(self):
353 # more than 255 positional-only arguments, should compile ok
354 fundef = "def f(%s, /):\n pass\n" % ', '.join('i%d' % i for i in range(300))
355 compile(fundef, "<test>", "single")
356
357 def test_serialization(self):
358 pickled_posonly = pickle.dumps(global_pos_only_f)
359 pickled_optional = pickle.dumps(global_pos_only_and_normal)
360 pickled_defaults = pickle.dumps(global_pos_only_defaults)
361
362 unpickled_posonly = pickle.loads(pickled_posonly)
363 unpickled_optional = pickle.loads(pickled_optional)
364 unpickled_defaults = pickle.loads(pickled_defaults)
365
366 self.assertEqual(unpickled_posonly(1,2), (1,2))
367 expected = r"global_pos_only_f\(\) got some positional-only arguments "\
368 r"passed as keyword arguments: 'a, b'"
369 with self.assertRaisesRegex(TypeError, expected):
370 unpickled_posonly(a=1,b=2)
371
372 self.assertEqual(unpickled_optional(1,2), (1,2))
373 expected = r"global_pos_only_and_normal\(\) got some positional-only arguments "\
374 r"passed as keyword arguments: 'a'"
375 with self.assertRaisesRegex(TypeError, expected):
376 unpickled_optional(a=1,b=2)
377
378 self.assertEqual(unpickled_defaults(), (1,2))
379 expected = r"global_pos_only_defaults\(\) got some positional-only arguments "\
380 r"passed as keyword arguments: 'a'"
381 with self.assertRaisesRegex(TypeError, expected):
382 unpickled_defaults(a=1,b=2)
383
384 def test_async(self):
385
386 async def f(a=1, /, b=2):
387 return a, b
388
389 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"):
390 f(a=1, b=2)
391
392 def _check_call(*args, **kwargs):
393 try:
394 coro = f(*args, **kwargs)
395 coro.send(None)
396 except StopIteration as e:
397 result = e.value
398 self.assertEqual(result, (1, 2))
399
400 _check_call(1, 2)
401 _check_call(1, b=2)
402 _check_call(1)
403 _check_call()
404
405 def test_generator(self):
406
407 def f(a=1, /, b=2):
408 yield a, b
409
410 with self.assertRaisesRegex(TypeError, r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'"):
411 f(a=1, b=2)
412
413 gen = f(1, 2)
414 self.assertEqual(next(gen), (1, 2))
415 gen = f(1, b=2)
416 self.assertEqual(next(gen), (1, 2))
417 gen = f(1)
418 self.assertEqual(next(gen), (1, 2))
419 gen = f()
420 self.assertEqual(next(gen), (1, 2))
421
422 def test_super(self):
423
424 sentinel = object()
425
426 class ESC[4;38;5;81mA:
427 def method(self):
428 return sentinel
429
430 class ESC[4;38;5;81mC(ESC[4;38;5;149mA):
431 def method(self, /):
432 return super().method()
433
434 self.assertEqual(C().method(), sentinel)
435
436 def test_annotations_constant_fold(self):
437 def g():
438 def f(x: not (int is int), /): ...
439
440 # without constant folding we end up with
441 # COMPARE_OP(is), IS_OP (0)
442 # with constant folding we should expect a IS_OP (1)
443 codes = [(i.opname, i.argval) for i in dis.get_instructions(g)]
444 self.assertNotIn(('UNARY_NOT', None), codes)
445 self.assertIn(('IS_OP', 1), codes)
446
447
448 if __name__ == "__main__":
449 unittest.main()