Added function to create a .env.local file

powershell/src/Public/Set-LocalEnvFileVariable.ps1

@@ -0,0 +1,79 @@
+Set-StrictMode -Version Latest
+
+<#
+.SYNOPSIS
+    Sets a variable in a Docker environment (.env.local) file.
+.DESCRIPTION
+    Sets a variable in a Docker environment (.env.local) file.
+    Assumes .env.local file is in the current directory by default.
+.PARAMETER Variable
+    Specifies the variable name.
+.PARAMETER Value
+    Specifies the variable value.
+.PARAMETER AsLiteral
+    Specifies whether the Value should be written as a literal (i.e wrapped in single quotes)
+.PARAMETER Path
+    Specifies the Docker environment (.env.local) file path. Assumes .env.local file is in the current directory by default.
+.EXAMPLE
+    PS C:\> Set-LocalEnvFileVariable -Variable VAR1 -Value "value one"
+.EXAMPLE
+    PS C:\> "value one" | Set-EnvFileVariable "VAR1"
+.EXAMPLE
+    PS C:\> Set-LocalEnvFileVariable -Variable VAR1 -Value "value one" -Path .\src\.env.local
+.EXAMPLE
+    PS C:\> Set-LocalEnvFileVariable -Variable VAR1 -Value "literal $tring" -AsLiteral
+.INPUTS
+    System.String. You can pipe in the Value parameter.
+.OUTPUTS
+    None.
+#>
+function Set-LocalEnvFileVariable
+{
+    Param (
+        [Parameter(Mandatory = $true, Position = 0)]
+        [ValidateNotNullOrEmpty()]
+        [string]
+        $Variable,
+
+        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
+        [ValidateNotNull()]
+        [AllowEmptyString()]
+        [string]
+        $Value,
+
+        [switch]
+        $AsLiteral = $false,
+
+        [string]
+        $Path = ".\.env.local"
+    )
+
+    if (!(Test-Path $Path)) {
+        throw "The environment file $Path does not exist"
+    }
+
+    if ($AsLiteral){
+          # Escape any ' to avoid terminating the value unexpectedly
+        $Value = "'$($Value.Replace("'", "''"))'"
+    }
+
+    $found = $false
+
+    $lines = @(Get-Content $Path -Encoding UTF8 | ForEach-Object {
+        if ($_ -imatch "^$Variable=.*") {
+            # Escape any '$' to prevent being used as a regex substitution
+            $Value = $Value.Replace('$', '$$')
+            $_ -ireplace "^$Variable=.*", "$Variable=$Value"
+            $found = $true
+        }
+        else {
+            $_
+        }
+    })
+
+    if (!$found) {
+        $lines += "$Variable=$Value"
+    }
+
+    WriteLines -File (Resolve-Path $Path) -Content $lines -Encoding ([System.Text.Encoding]::UTF8)
+}