Refactor duplicated []string→[]interface{} conversions into strutil.StringsToAny

internal/config/guard_policy_validation.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"sort"
 	"strings"
+
+	"github.com/github/gh-aw-mcpg/internal/strutil"
 )
 
 const errMsgPolicyMissingKey = "policy must include allow-only or write-sink"
@@ -186,11 +188,7 @@ func NormalizeGuardPolicy(policy *GuardPolicy) (*NormalizedGuardPolicy, error) {
 		return normalized, nil
 
 	case []string:
-		generic := make([]interface{}, len(scope))
-		for i := range scope {
-			generic[i] = scope[i]
-		}
-		scopes, err := normalizeAndValidateScopeArray(generic)
+		scopes, err := normalizeAndValidateScopeArray(strutil.StringsToAny(scope))
 		if err != nil {
 			return nil, err
 		}

internal/guard/wasm_payload.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/github/gh-aw-mcpg/internal/config"
+	"github.com/github/gh-aw-mcpg/internal/strutil"
 )
 
 // normalizePolicyPayload coerces a policy value to a map[string]interface{}.
@@ -250,24 +251,16 @@ func BuildLabelAgentPayload(policy interface{}, trustedBots []string, trustedUse
 
 	if len(trustedBots) > 0 {
 		// trusted-bots is a top-level key in the label_agent payload.
-		// Convert []string to []interface{} for JSON compatibility.
-		bots := make([]interface{}, len(trustedBots))
-		for i, b := range trustedBots {
-			bots[i] = b
-		}
+		bots := strutil.StringsToAny(trustedBots)
 		payload["trusted-bots"] = bots
 		logWasm.Printf("BuildLabelAgentPayload: injected %d trusted-bots into payload", len(trustedBots))
 	}
 
 	if len(trustedUsers) > 0 {
 		// trusted-users is injected inside the allow-only object.
-		// Convert []string to []interface{} for JSON compatibility.
 		// If allow-only is absent, the injection is skipped and buildStrictLabelAgentPayload
 		// will reject the payload when called with the missing allow-only key.
-		users := make([]interface{}, len(trustedUsers))
-		for i, u := range trustedUsers {
-			users[i] = u
-		}
+		users := strutil.StringsToAny(trustedUsers)
 		// Inject into allow-only object if present
 		if allowOnly, ok := payload["allow-only"].(map[string]interface{}); ok {
 			allowOnly["trusted-users"] = users

internal/strutil/strings_to_any_test.go

@@ -0,0 +1,26 @@
+package strutil
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStringsToAny(t *testing.T) {
+	t.Parallel()
+
+	t.Run("nil input returns empty (non-nil) slice", func(t *testing.T) {
+		t.Parallel()
+		assert.Equal(t, []interface{}{}, StringsToAny(nil))
+	})
+
+	t.Run("empty input returns empty slice", func(t *testing.T) {
+		t.Parallel()
+		assert.Empty(t, StringsToAny([]string{}))
+	})
+
+	t.Run("converts all entries preserving order", func(t *testing.T) {
+		t.Parallel()
+		assert.Equal(t, []interface{}{"octo", "hub", "bot"}, StringsToAny([]string{"octo", "hub", "bot"}))
+	})
+}

internal/strutil/strutil.go

@@ -28,6 +28,15 @@ func DeduplicateStrings(input []string, sorted bool) []string {
 	return out
 }
 
+// StringsToAny converts a []string to []interface{}.
+func StringsToAny(input []string) []interface{} {
+	out := make([]interface{}, len(input))
+	for i, value := range input {
+		out[i] = value
+	}
+	return out
+}
+
 // GetStringFromMap returns the first non-empty string value found for any of
 // the given keys in m.  For each key, the value must be present, typed as
 // string, and non-empty to be returned.  Returns an empty string when no