Powershell Newman run pass --env-var as string

Trying to run via powershell postman collection as following:

newman run $collPath -e $envPath $envVarsStr

where $envVarsStr is a string containg N number dynamically generated --env-var e.g.

--env-var "Base.Url=someurl" --env-var "Password=somepass"

But newman seems to ignore all my --env-vars Using extra file is really not an option for me.

Any ideas on how to pass env-var string correctly?

Solution

You cannot pass what an external program should see as multiple arguments via a single string, because PowerShell passes a string as a single argument, irrespective of the string's content.

Instead, use an array of strings, each element of which is passed as a separate argument.

Thus, if you control the creation of the arguments, use the following:

# Construct an array of arguments.
# Note: No *embedded* " quoting necessary - PowerShell will double-quote on demand.
$envVarsArgs = 
  '--env-var',
  'Base.Url=someurl', # use variables or expressions as needed
  '--env-var',
  'Password=somepass'

and then call newman as follows:

# Note: @envVarsArgs would work too.
newman run $collPath -e $envPath $envVarsArgs

If you're given a single string encoding multiple arguments, you can split it into an array of individual arguments yourself, which in the simplest case means:

newman run $collPath -e $envPath (-split $envVarsStr -replace '"')

However, this is not enough if any of the double-quoted substrings contain spaces (e.g. --env-var "Foo=bar none"), because the unary form of -split splits by whitespace only.

If you need to deal with a given string whose embedded quoted arguments have spaces, you can use Invoke-Expression with an expandable (double-quoted) string ("...") in a pinch.

Note: Invoke-Expression (iex) should generally be the last resort, due to its security risks: only ever use it on input you either provided yourself or fully trust - see this answer.

# !! See warning re Invoke-Expression above.
Invoke-Expression @"
newman run "$collPath" -e "$envPath" $envVarsStr
"@

^{Note the use of an expandable here-string (@"<newline>...<newline>"@), which simplifies embedded quoting (no need to escape the embedded " chars.)}

Another option is to use --%, the stop-parsing token, which, however, requires you to define an auxiliary environment variable that duplicates the value of your $envVarsStr variable:

Note: --% has many limitations - see this answer.

# Duplicate the string stored in $envVarsStr
# in an aux. environment variable, so it can be used with --%
$env:__aux = $envVarsStr

# Note the use of --% and the cmd.exe-style environment-variable
# reference:
newman run $collPath -e $envPath --% %__aux%