Bug: define_macro & embed doesn't work as expected inside a method vs __main__

If I have a macro inside a function doesn’t work as expected, the same is working fine on __main__ condition. Why?

Define Macro in function throws an error…!

import IPython as ipy
from IPython.terminal.interactiveshell import TerminalInteractiveShell

def run():
    shell = TerminalInteractiveShell.instance()
    shell.define_macro('foo', """a,b=10,20""")
    ipy.embed(display_banner=False)

if __name__ == "__main__":
    run()

⋊> ~/c/i/i/ipycli on master ⨯ ipython test
In [1]: foo
Out[1]: IPython.macro.Macro('a,b=10,20\n')
In [2]: a,b
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-3-2fbdd1b4fa70> in <module>
----> 1 a,b
NameError: name 'a' is not defined

Define Macro in main works fine…!

import IPython as ipy
from IPython.terminal.interactiveshell import TerminalInteractiveShell

if __name__ == "__main__":
    shell = TerminalInteractiveShell.instance()
    shell.define_macro('foo', """a,b=10,20""")
    ipy.embed(display_banner=False)

⋊> ~/c/i/i/ipycli on master ⨯ ipython test
In [1]: foo
In [2]: a,b
Out[2]: (10, 20)

IPython version 7.14.0 OS: macOS Catalina Terminal: iTerm2 version 3.3.9

[kirankotari]

Got the solution, after defining the I need assign manually when I am calling the embed from function x, y = shell.user_ns['x'], shell.user_ns['y'] before ipy.embed(display_banner=False)

[kirankotari]

@Carreau updated the question with proper code, please help @minrk @takluyver