How to pass arguments via powershell scripts

tl;dr

If your .ps1 script doesn't explicitly declare parameters, use the automatic $args variable variable to pass all arguments it received through to your node script:

node ./main.js $args

PowerShell scripts (and functions) may explicitly declare parameters to bind arguments passed to them on invocation, using a param() block - see the conceptual about_Scripts help topic.

In the absence of parameter declarations,^[1] arguments are reported via the automatic $args variable, which is a regular PowerShell array of type [object[]], whose first element ($args[0]) is the first argument.^[2]

Note:

• Passing an array such as $args to an external program passes the elements as individual arguments, which is appropriate (given that external program CLIs generally have no concept of arrays).

• By contrast, if you invoke a PowerShell command with $args, the array is passed as a single argument, i.e. the array is passed as a whole, as the first and only positional argument.

  • To properly relay $args to PowerShell commands, use @args, which (due to $args-specific magic) even works with named arguments (e.g., -foo bar). This technique is known as splatting

^{[1] Technically, as long as your script or function is not an advanced one, $args can be combined with explicit parameter declarations, in that $args then only contains extra arguments, i.e. those that weren't bound to declared parameters.
By contrast, the preferable advanced scripts and functions (cmdlet-like, those that have a [CmdletBinding()] and/or [Parameter()] attributes) do not support extra arguments at all, and report an error. Supporting extra arguments in advanced scripts/functions requires declaration of a catch-all parameter, via the [Parameter() attribute's ValueFromRemainingArguments property - see this answer for an example.}

^{[2] That is, unlike in C programs, for instance, $args doesn't also include the running script's name or path, as the first element.}