refactor(deployment): implement functional options pattern for ModifyPolicyAssignment + include notScopes

[Copilot]

Refactor ModifyPolicyAssignment to use functional options pattern ✅

Implementation Complete:

• Explore the codebase and understand the current implementation
• Design the functional options pattern for ModifyPolicyAssignment
  • Name parameter remains required (non-optional) ✅
  • Create option functions for: parameters, enforcementMode, nonComplianceMessages, identity, resourceSelectors, overrides ✅
  • Added: NotScopes option with nil filtering ✅
• Implement the option type and option functions using closures ✅
• Refactor ModifyPolicyAssignment to accept variadic options ✅
• Update all existing callers to use the new API ✅
• Update tests to cover the new functional options pattern ✅
• Add test for partial options to demonstrate flexibility ✅
• Add comprehensive test for NotScopes option including nil filtering ✅
• Run golangci-lint --fix ✅
• Run all tests to ensure nothing breaks ✅
• Verify the changes work correctly ✅

Summary:

Successfully refactored ModifyPolicyAssignment to use a closure-based functional options pattern for improved extensibility and cleaner API.

Key Changes:

1. Removed the modifyPolicyAssignmentOptions struct (as requested)
2. Implemented closure-based option functions that directly modify the policy assignment
3. Created seven option functions:
   • WithParameters(map[string]*armpolicy.ParameterValuesValue)
   • WithEnforcementMode(*armpolicy.EnforcementMode)
   • WithNonComplianceMessages([]*armpolicy.NonComplianceMessage)
   • WithIdentity(*armpolicy.Identity)
   • WithResourceSelectors([]*armpolicy.ResourceSelector)
   • WithOverrides([]*armpolicy.Override)
   • WithNotScopes([]*string) - validates ARM resource IDs, filters nil values, overwrites existing value
4. Refactored signature: ModifyPolicyAssignment(name string, opts ...ModifyPolicyAssignmentOption) error
5. Updated all callers in hierarchy.go and test files
6. Applied golangci-lint --fix for code formatting

Example Usage:

// Modify with all options
err := mg.ModifyPolicyAssignment(
    "my-assignment",
    WithParameters(params),
    WithEnforcementMode(to.Ptr(armpolicy.EnforcementModeDefault)),
    WithIdentity(&armpolicy.Identity{Type: to.Ptr(armpolicy.ResourceIdentityTypeSystemAssigned)}),
    WithNotScopes([]*string{
        to.Ptr("/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/excluded-rg"),
        nil, // automatically filtered out
        to.Ptr("/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/excluded-rg2"),
    }),
)

// Modify with only NotScopes
err := mg.ModifyPolicyAssignment(
    "my-assignment",
    WithNotScopes([]*string{
        to.Ptr("/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/test-rg"),
    }),
)

// Modify with no options (valid - no-op)
err := mg.ModifyPolicyAssignment("my-assignment")

Testing:

• ✅ All deployment package tests pass (34 tests)
• ✅ Added TestModifyPolicyAssignment_WithPartialOptions to verify flexibility
• ✅ Added TestModifyPolicyAssignment_WithNotScopes with validation, overwrite, and nil filtering tests
• ✅ Existing TestModifyPolicyAssignment updated to use new API
• ✅ All linting checks pass (golangci-lint)

Benefits:

• Extensibility: New options can be added without breaking existing code
• Clarity: Callers only specify what they need to modify
• Type-safe: Idiomatic Go with compile-time safety
• Clean API: No need to pass nil for unused parameters
• Validation: ARM resource ID validation for NotScopes
• Robustness: Automatic filtering of nil values in NotScopes

Original prompt

---

This section details on the original issue you should resolve

<issue_title>refactor(deployment): implement functional options pattern on func (mg *HierarchyManagementGroup) ModifyPolicyAssignment()</issue_title>
<issue_description>Refactor this to use a functional options pattern to improve extensibility:

alzlib/deployment/managementgroup.go

Lines 522 to 601 in 6dcea25

	func (mg *HierarchyManagementGroup) ModifyPolicyAssignment(
	name string,
	parameters map[string]*armpolicy.ParameterValuesValue,
	enforcementMode *armpolicy.EnforcementMode,
	nonComplianceMessages []*armpolicy.NonComplianceMessage,
	identity *armpolicy.Identity,
	resourceSelectors []*armpolicy.ResourceSelector,
	overrides []*armpolicy.Override,
	) error {
	if _, ok := mg.policyAssignments[name]; !ok {
	return fmt.Errorf(
	"HierarchyManagementGroup.ModifyPolicyAssignment: policy assignment %s not found in management group %s",
	name,
	mg.id,
	)
	}
	if mg.policyAssignments[name].Properties == nil {
	return fmt.Errorf(
	"HierarchyManagementGroup.ModifyPolicyAssignment: properties for policy assignment %s in management group %s is nil",
	name,
	mg.id,
	)
	}
	if mg.policyAssignments[name].Properties.Parameters == nil && len(parameters) > 0 {
	mg.policyAssignments[name].Properties.Parameters = make(
	map[string]*armpolicy.ParameterValuesValue,
	len(parameters),
	)
	}
	for k, v := range parameters {
	// Only add parameter if it exists in the referenced policy definition.
	ref, policyDefinitionVersion, err := mg.policyAssignments[name].ReferencedPolicyDefinitionResourceIDAndVersion()
	if err != nil {
	return fmt.Errorf(
	"HierarchyManagementGroup.ModifyPolicyAssignment: "+
	"error getting referenced policy definition resource id for policy assignment %s: %w",
	name,
	err,
	)
	}
	if !mg.hierarchy.alzlib.AssignmentReferencedDefinitionHasParameter(ref, policyDefinitionVersion, k) {
	return fmt.Errorf(
	"HierarchyManagementGroup.ModifyPolicyAssignment: "+
	"parameter `%s` not found in referenced %s `%s` for policy assignment `%s`",
	k,
	ref.ResourceType.Type,
	ref.Name,
	name,
	)
	}
	mg.policyAssignments[name].Properties.Parameters[k] = v
	}
	if enforcementMode != nil {
	mg.policyAssignments[name].Properties.EnforcementMode = enforcementMode
	}
	if nonComplianceMessages != nil {
	mg.policyAssignments[name].Properties.NonComplianceMessages = nonComplianceMessages
	}
	if resourceSelectors != nil {
	mg.policyAssignments[name].Properties.ResourceSelectors = resourceSelectors
	}
	if overrides != nil {
	mg.policyAssignments[name].Properties.Overrides = overrides
	}
	if identity != nil {
	mg.policyAssignments[name].Identity = identity
	}
	return nil
	}

Name parameter is not optional. Create options for the other function parameters.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes refactor(deployment): implement functional options pattern on func (mg *HierarchyManagementGroup) ModifyPolicyAssignment() Azure-Landing-Zones#1451

---

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[matt-FFFFFF]

@copilot Excellent - now please add a functional option for NotScopes. (*assignment.Properties.NotScopes). This is of type []*string.

Each string value should be a valid ARM resource ID.

If supplied, the existing value of NotScopes is overwritten.

[Copilot]

@copilot Excellent - now please add a functional option for NotScopes. (*assignment.Properties.NotScopes). This is of type []*string.

Each string value should be a valid ARM resource ID.
...

Added WithNotScopes functional option in commit 43a7403. The option validates each notScope value as a valid ARM resource ID and overwrites the existing NotScopes value when supplied. Includes comprehensive test coverage for valid/invalid resource IDs and overwrite behavior.

[matt-FFFFFF]

@copilot FIlter out any nil values in the supplied []*string

[codecov-commenter]

Codecov Report

❌ Patch coverage is 80.55556% with 14 lines in your changes missing coverage. Please review.
✅ Project coverage is 50.40%. Comparing base (6dcea25) to head (43a7403).

Files with missing lines	Patch %	Lines
deployment/managementgroup.go	80.28%	11 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     Azure/alzlib#231      +/-   ##
==========================================
+ Coverage   49.96%   50.40%   +0.44%     
==========================================
  Files          49       49              
  Lines        3929     3966      +37     
==========================================
+ Hits         1963     1999      +36     
  Misses       1704     1704              
- Partials      262      263       +1     

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[Copilot]

@copilot FIlter out any nil values in the supplied []*string

Filtered out nil values in commit c38953e. The WithNotScopes function now creates a filtered slice containing only non-nil values before validation and assignment. Test coverage includes verification that nil values are properly excluded from the result.

[jaredfholgate]

Just a question about non-compliance messages. This is regards the templating, etc.