reafactor: refactor state upgraders

Author: tamas-jozsa

integration/v4_to_v5/testdata/page_rule/expected/page_rule.tf

@@ -77,6 +77,7 @@ resource "cloudflare_page_rule" "with_cache_key_fields" {
       user = {
         device_type = true
         geo         = false
+        lang        = false
       }
     }
   }

integration/v4_to_v5/testdata/page_rule/expected/terraform.tfstate

@@ -1,13 +1,11 @@
 package load_balancer_pool
 
 import (
-	"fmt"
 	"strings"
 
 	"github.com/hashicorp/hcl/v2/hclsyntax"
 	"github.com/hashicorp/hcl/v2/hclwrite"
 	"github.com/tidwall/gjson"
-	"github.com/tidwall/sjson"
 
 	"github.com/cloudflare/tf-migrate/internal"
 	"github.com/cloudflare/tf-migrate/internal/transform"
@@ -166,59 +164,14 @@ func transformHeaderBlock(body *hclwrite.Body) {
 }
 
 func (m *V4ToV5Migrator) TransformState(ctx *transform.Context, stateJSON gjson.Result, resourcePath, resourceName string) (string, error) {
-	result := stateJSON.String()
-
-	// Transform load_shedding from array to object (or null if empty)
-	// v4: "load_shedding": [{ ... }] or []
-	// v5: "load_shedding": { ... } or null
-	loadShedding := stateJSON.Get("attributes.load_shedding")
-	if loadShedding.Exists() && loadShedding.IsArray() {
-		if len(loadShedding.Array()) > 0 {
-			firstElement := loadShedding.Array()[0]
-			result, _ = sjson.Set(result, "attributes.load_shedding", firstElement.Value())
-		} else {
-			// Empty array -> null
-			result, _ = sjson.Set(result, "attributes.load_shedding", nil)
-		}
-	}
-
-	// Transform origin_steering from array to object (or null if empty)
-	// v4: "origin_steering": [{ ... }] or []
-	// v5: "origin_steering": { ... } or null
-	originSteering := stateJSON.Get("attributes.origin_steering")
-	if originSteering.Exists() && originSteering.IsArray() {
-		if len(originSteering.Array()) > 0 {
-			firstElement := originSteering.Array()[0]
-			result, _ = sjson.Set(result, "attributes.origin_steering", firstElement.Value())
-		} else {
-			// Empty array -> null
-			result, _ = sjson.Set(result, "attributes.origin_steering", nil)
-		}
-	}
-
-	// Transform header field inside each origin from array to object/null
-	// v4: origins[*].header = [] or [{ ... }]
-	// v5: origins[*].header = {} or null (provider expects object, not array)
-	// Re-parse to get updated state after previous transformations
-	updatedState := gjson.Parse(result)
-	origins := updatedState.Get("attributes.origins")
-	if origins.Exists() && origins.IsArray() {
-		originsArray := origins.Array()
-		for i, origin := range originsArray {
-			header := origin.Get("header")
-			if header.Exists() && header.IsArray() {
-				if len(header.Array()) == 0 {
-					// Empty array -> empty object (v5 provider expects object type)
-					result, _ = sjson.Set(result, fmt.Sprintf("attributes.origins.%d.header", i), map[string]interface{}{})
-				} else {
-					// Non-empty array -> convert first element to object
-					// This handles the case where v4 had header as array of objects
-					firstElement := header.Array()[0]
-					result, _ = sjson.Set(result, fmt.Sprintf("attributes.origins.%d.header", i), firstElement.Value())
-				}
-			}
-		}
-	}
-
-	return result, nil
+	// State transformation is now handled by the provider's StateUpgraders (UpgradeState)
+	// The provider's migration/v500 package handles all state transformations:
+	// - load_shedding: array[0] → object
+	// - origin_steering: array[0] → object
+	// - origins.header: array → object with structure change
+	// - check_regions: Set → List
+	//
+	// This function is a no-op for cloudflare_load_balancer_pool migration.
+	// The provider automatically applies state upgrades when users run `terraform apply`.
+	return stateJSON.String(), nil
 }