5.1 Hashtable Expression Parsing

[mattcargile]

In 5.1, when the key's value is an expression ( maybe only if ), you see red. while kind of breaks with a stream of errors. foreach does work. try {} catch {} does not work. try {} finally {} works.

This is fixed in modern PowerShell ( at least 7.6.1 ).

@{
    Value1 = if ($true) {'SomeValue'}
    Value2 = 'OtherValue'
}

The above throws the below.

At line:2 char:38
+     Value1 = if ($true) {'SomeValue'}
+                                      ~
The hash literal was incomplete.
At line:3 char:5
+     Value2 = 'OtherValue'
+     ~~~~~~
Unexpected token 'Value2' in expression or statement.
At line:5 char:1
+ }
+ ~
Unexpected token '}' in expression or statement.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : IncompleteHashLiteral

The workaround could be adding a semicolon

@{
    Value1 = if ($true) {'SomeValue'};
    Value2 = 'OtherValue'
}

or wrapping in sub-expression operator

@{
    Value1 = $(if ($true) {'SomeValue'})
    Value2 = 'OtherValue'
}

or you can add an else. ( NOTE: Removing $null in else {} to keep the same semantics. See @surfingoldelephant's comments below.

@{
    Value1 = if ($true) {'SomeValue'} else {}
    Value2 = 'OtherValue'
}

Props to @kborowinski on PowerShell Discord for discovering it. Appears the parser gets "stuck" in the "else/elseif" mode.

[surfingoldelephant]

In case it's of interest, here's the original issue and fix (made in v6.1):

• Hashtable literal parsing fails when using an if statement as value PowerShell/PowerShell#6970
• Fix parser to continue parsing key-value pairs after an If-Statement value in a HashExpression PowerShell/PowerShell#7002

or you can add an else

@{
    Value1 = if ($true) {'SomeValue'} else {$null}
    Value2 = 'OtherValue'
}

Just watch out for else { $null }. That workaround isn't equivalent to the others.

When the condition is $false, the other workarounds will result in Value1 being AutomationNull, not $null, due to statement assignment having pipeline semantics.

For the else workaround to be equivalent, you'd need to do this instead:

@{
    Value1 = if ($true) { 'SomeValue' } else {}
    Value2 = 'OtherValue'
}

[nightroman]

For sad reasons I am not maintaining this now.