How to modify Json using Powershell

Question

I have the following JSON held in a file "test.json":

{
  "metadata": [
    {
      "src": [
        {
          "files": [
            "src/**.csproj"
          ]
        }
      ],
      "dest": "api",
      "disableGitFeatures": false,
      "disableDefaultFilter": false
    }
  ]
}

I'd like to modify the "src" element. Instead of:

  "src": [
    {
      "files": [
        "src/**.csproj"
      ]
    }
  ],

It needs to be:

    "src": [
        {
          "files": [
            "*.csproj"
          ],
          "cwd":".."
        }
      ],

Where I modify the first element of "files" and add "cwd". This should be straight forward but I'm struggling to achieve this in powershell. Can anyone point me in the right direction of any examples of this?

Thanks for any pointers in advance.

Answer 1

You can do the following:

$JSONObject = Get-Content test.json -Raw | ConvertFrom-Json
$JSONObject.metadata.src.files = ,'*.csproj'
$JSONObject.metadata.src | Add-Member -Name 'cwd' -Value '..' -MemberType NoteProperty
$JSONObject | ConvertTo-Json -Depth 5 | Set-Content test.json

The tricky part is to make sure the .files value is an array of a single element. You can do this with the array subexpression operator @() or the unary operator , .