While working on Microservice development using NODE JS and PowerShell I have got stumped on Parameterization issue. So far I was working with single parameter all went fine and now got a new scenario where I need to work with two parameters with space as well. Interesting right? Yes, I meant the white space in the routes.

Look at this now!

http://localhost:3000/DisplayName/Chendrayan Venkatesan – Which turns out as http://localhost:3000/DisplayName/Chendrayan%20Venkatesan – Expected but didn’t work. Here my display name Chendrayan Venkatesan should be passed in routes as parameter value for PowerShell script

Failing Code – Using child_process module

app.get("/User/:DisplayName", function (request, response) {
    child = spawn("powershell.exe",
        [ "C:\\scripts\\demo.ps1 -DisplayName" + request.params.DisplayName ]
    )
    console.log(request.params.DisplayName)
    child.stdout.pipe(response)
})

My assumption was the value of request.params.DisplayName should be “Chendrayan%20Venkatesan” but it wasn’t

console.log(request.params.DisplayName) – Returned “Chendrayan Venkatesan” absolutely fine!

I tried for few hours over internet and didn’t find the solution to meet my need. So, with no wait I used node-powershell which works like charm!

Using node-powershell module

app.get("/user/:DisplayName", function (request, response) {
    ps.addCommand('./scripts/demo.ps1', [ {
        name: "DisplayName",
        value: request.params.DisplayName
    } ])
    ps.invoke().then(output => {
        response.send(output)
    })
})

This works! Sample PS code is below!

param(
    $DisplayName
)

process {
    $adsi = [adsisearcher]::new()
    $adsi.Filter = "(&(ObjectCategory=User)(displayname=$DisplayName))"
    $user = $adsi.FindOne()
    if($user) {
        $user.properties
    }
    else {
        "Something went wrong"
    }
}

Parameter as Name Value Pair

ps.addCommand('./scripts/demo.ps1', [ {
    name: "DisplayName",
    value: request.params.DisplayName
} ])

How to pass multiple parameters?

app.get("/add/:var1/:var2", function (request, response) {
    ps.addCommand("./scripts/demo.ps1", [ {
        name: "var1",
        value: request.params.var1
    }, {
        name: "var2",
        value: request.params.var2
    } ])
    ps.invoke().then(output=>{
        response.send(output)
    })
})

It’s that simple! Now  you plan your PowerShell script ! Mine is ugly like shown below

param (
    $var1,

    $var2
)

process {
    $var1 + $var2 
}

Navigate to http://localhost:3000/3/4 – Returns 7 on your browser.