config editor

src/Configuration/Remove-PersonaConditionNode.ps1

@@ -0,0 +1,67 @@
+function Remove-PersonaConditionNode {
+    <#
+    .SYNOPSIS
+        Removes a condition or nested group from a rule's condition tree (FR-028).
+
+    .DESCRIPTION
+        Two structural rules are enforced here rather than left to schema validation,
+        because both would otherwise produce a document the schema calls invalid with
+        no indication which editor action caused it:
+
+          - The root group itself cannot be removed - a rule's `match` is required
+            (RE-001). Delete the rule instead (Remove-PersonaConfigRule).
+          - A group's last remaining condition cannot be removed - an empty
+            `conditions` array violates the schema's `minItems: 1` on conditionGroup.
+            Remove the parent group instead, or add a replacement first.
+
+    .PARAMETER Group
+        The rule's `match` condition group (the root).
+
+    .PARAMETER Path
+        Path (see Get-PersonaConditionNode) to the node to remove. Must not be empty.
+
+    .OUTPUTS
+        System.Object - the same Group, mutated in place, returned for convenience.
+    #>
+    [CmdletBinding()]
+    [OutputType([object])]
+    param(
+        [Parameter(Mandatory)]
+        [object] $Group,
+
+        [Parameter(Mandatory)]
+        [AllowEmptyCollection()]
+        [int[]] $Path
+    )
+
+    if (@($Path).Count -eq 0) {
+        throw "The root condition group cannot be removed this way - delete the rule instead."
+    }
+
+    # Special-cased at length 1 because PowerShell's range operator treats 0..-1 as
+    # the two-element descending range (0, -1), not an empty range - the naive slice
+    # would silently pick up the wrong parent for a top-level path.
+    $parentPath = (@($Path).Count -eq 1) ? @() : @($Path)[0..($Path.Count - 2)]
+    $index = @($Path)[-1]
+
+    $parent = Get-PersonaConditionNode -Group $Group -Path $parentPath
+    $children = @($parent.conditions)
+
+    if ($index -lt 0 -or $index -ge $children.Count) {
+        throw "Path segment $index is out of range - this group has $($children.Count) condition(s)."
+    }
+
+    if ($children.Count -eq 1) {
+        throw 'This is the only condition in its group. A group requires at least one condition - remove the group itself instead, or add a replacement first.'
+    }
+
+    # Removed by position, not by value or reference - two structurally identical
+    # sibling conditions are otherwise indistinguishable.
+    $remaining = [System.Collections.Generic.List[object]]::new()
+    for ($i = 0; $i -lt $children.Count; $i++) {
+        if ($i -ne $index) { $remaining.Add($children[$i]) }
+    }
+    $parent.conditions = $remaining.ToArray()
+
+    $Group
+}