{Core} Entry script: Use @args to tolerate incorrectly passing list with $

[jiasli]

Close #23797

#23514 changed the entry script az.cmd to az.ps1 when executed in PowerShell.

& "$PSScriptRoot\..\python.exe" -IBm azure.cli $args

Consider we have an array

> $mylist = "a", "b"

Some user passes the array to az.ps1 as $mylist:

> az --debug $mylist
cli.knack.cli: Command arguments: ['--debug', 'a b']

This is incorrect, as $args will become an array of array. Using $args to call a native exe will only splat the outer array and concatenate the inner array's items.

The correct way to a pass a list to az is to pass space-separated arguments, so in PowerShell, user should use @ splatting when calling az.ps1:

> az --debug @mylist
cli.knack.cli: Command arguments: ['--debug', 'a', 'b']

Meanwhile, when calling native exe with @args, it will even splat internal arrays. We can use a test script test.ps1 to verify this behavior:

echo $args.Length $args.GetType()
echo $args[0].GetType()
python -c "import sys; print(sys.argv)" $args
python -c "import sys; print(sys.argv)" @args

> ./test.ps1 $mylist $mylist
2

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array
True     True     Object[]                                 System.Array
['-c', 'a b', 'a b']
['-c', 'a', 'b', 'a', 'b']

> ./test.ps1 @mylist @mylist
4

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array
True     True     String                                   System.Object
['-c', 'a', 'b', 'a', 'b']
['-c', 'a', 'b', 'a', 'b']

Interesting thing is that even @args can only splat 2 layers and the 3rd layer was concatenated:

> ./test.ps1 ($mylist, $mylist)
1

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array
True     True     Object[]                                 System.Array
['-c', 'System.Object[] System.Object[]']
['-c', 'a b', 'a b']

We can go even deeper:

> ./test.ps1 (($mylist, $mylist),($mylist, $mylist))
1

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array
True     True     Object[]                                 System.Array
['-c', 'System.Object[] System.Object[]']
['-c', 'System.Object[] System.Object[]', 'System.Object[] System.Object[]']

[jiasli]

CI task "Check the Format of Pull Request Title and Content" failed because of some example commands in the PR description @wangzelin007:

https://dev.azure.com/azure-sdk/public/_build/results?buildId=1835012&view=logs&j=a8943ac2-38d7-5792-f2a7-5f4fd06db24e&t=3ed51913-4dd7-564f-a8d8-fda07de13946&l=115

['-c', 'a b', 'a b']: missing space after ]
                   ↑

[jiasli]

The disadvantage of using @args is also obvious, as we can't pass "a b" string as ("a", "b") now.

[wangzelin007]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).