add doc string co tests

Author: xuantengh

Lib/test/test_code.py

@@ -123,6 +123,61 @@
 flags: 3
 consts: ('None',)
 
+>>> def has_docstring(x: str):
+...     'This is a one-line doc string'
+...     x += x
+...     x += "hello world"
+...     # co_flags should be 0x4000003 = 67108867
+...     return x
+
+>>> dump(has_docstring.__code__)
+name: has_docstring
+argcount: 1
+posonlyargcount: 0
+kwonlyargcount: 0
+names: ()
+varnames: ('x',)
+cellvars: ()
+freevars: ()
+nlocals: 1
+flags: 67108867
+consts: ("'This is a one-line doc string'", "'hello world'")
+
+>>> async def async_func_docstring(x: str, y: str):
+...     "This is a docstring from async function"
+...     import asyncio
+...     await asyncio.sleep(1)
+...     # co_flags should be 0x4000083 = 67108995
+...     return x + y
+
+>>> dump(async_func_docstring.__code__)
+name: async_func_docstring
+argcount: 2
+posonlyargcount: 0
+kwonlyargcount: 0
+names: ('asyncio', 'sleep')
+varnames: ('x', 'y', 'asyncio')
+cellvars: ()
+freevars: ()
+nlocals: 3
+flags: 67108995
+consts: ("'This is a docstring from async function'", '0', 'None', '1')
+
+>>> def no_docstring(x, y, z):
+...     return x + "hello" + y + z + "world"
+
+>>> dump(no_docstring.__code__)
+name: no_docstring
+argcount: 3
+posonlyargcount: 0
+kwonlyargcount: 0
+names: ()
+varnames: ('x', 'y', 'z')
+cellvars: ()
+freevars: ()
+nlocals: 3
+flags: 3
+consts: ("'hello'", "'world'")
 """
 
 import copy

Lib/test/test_compile.py

@@ -852,6 +852,7 @@ def test_remove_unused_consts_extended_args(self):
         eval(compile(code, "file.py", "exec"), g)
         exec(code, g)
         f = g['f']
+        # Issue #126072: None is no longer the first element in co_consts
         expected = tuple(['', 1] + [f't{i}' for i in range(N)])
         self.assertEqual(f.__code__.co_consts, expected)
         expected = "".join(expected[2:])
@@ -1244,6 +1245,7 @@ def return_genexp():
                     y)
         genexp_lines = [0, 4, 2, 0, 4]
 
+        # Issue #126072: None is no longer the first element in co_consts
         genexp_code = return_genexp.__code__.co_consts[0]
         code_lines = self.get_code_lines(genexp_code)
         self.assertEqual(genexp_lines, code_lines)

Lib/test/test_compiler_assemble.py

@@ -84,6 +84,7 @@ def inner():
                 return x
             return inner() % 2
 
+        # Issue #126072: None is no longer the first element in co_consts
         inner_code = mod_two.__code__.co_consts[0]
         assert isinstance(inner_code, types.CodeType)