direct: add FieldTriggers(); remove ClassifyChanges(), RecreateFields() (#3595)

## Changes
New method FieldTriggers(), which is a more powerful version of
RecreateFields() that allows associate any action with a field.

Builds on top of #3585

## Why
This covers existing classification use cases without custom code.

We might still need ClassifyChange function in the future, but exact
types involved will likely change by that time (with regard to
serialized plan work).

## Tests
Existing tests.

Author: denik

bundle/terranova/plan.go

@@ -207,22 +207,11 @@ func calcDiff(adapter *tnresources.Adapter, savedState, config any) (deployplan.
 		return deployplan.ActionTypeNoop, nil
 	}
 
-	if adapter.MustRecreate(localDiff) {
-		return deployplan.ActionTypeRecreate, nil
-	}
-
-	if adapter.HasClassifyChanges() {
-		result, err := adapter.ClassifyChanges(localDiff)
-		if err != nil {
-			return deployplan.ActionTypeUnset, err
-		}
-
-		if result == deployplan.ActionTypeUpdateWithID && !adapter.HasDoUpdateWithID() {
-			return deployplan.ActionTypeUnset, errors.New("internal error: unexpected plan='update_with_id'")
-		}
+	result := adapter.ClassifyByTriggers(localDiff)
 
-		return result, nil
+	if result == deployplan.ActionTypeUpdateWithID && !adapter.HasDoUpdateWithID() {
+		return deployplan.ActionTypeUnset, errors.New("internal error: unexpected plan='update_with_id'")
 	}
 
-	return deployplan.ActionTypeUpdate, nil
+	return result, nil
 }

bundle/terranova/tnresources/adapter.go

@@ -34,14 +34,10 @@ type IResource interface {
 	// Example: func (r *ResourceJob) DoDelete(ctx context.Context, id string) error {
 	DoDelete(ctx context.Context, id string) error
 
-	// [Optional] RecreateFields returns a list of fields that will cause resource recreation if changed
-	// Example: func (r *ResourceJob) RecreateFields() []string { return []string{"name", "type"} }
-	RecreateFields() []string
-
-	// [Optional] ClassifyChanges provides non-default change classification.
-	// Default is to consider any change "an update" (RecreateFields handled separately).
-	// Example: func (r *ResourceJob) ClassifyChanges(changes []structdiff.Change) deployplan.ActionType { return deployplan.ActionUpdate }
-	ClassifyChanges(changes []structdiff.Change) deployplan.ActionType
+	// [Optional] FieldTriggers returns actions to trigger when given fields are changed.
+	// Keys are field paths (e.g., ".name", ".catalog_name"). Values are actions.
+	// Unspecified changed fields default to ActionTypeUpdate.
+	FieldTriggers() map[string]deployplan.ActionType
 }
 
 // IResourceNoRefresh describes additional methods for resource to implement.
@@ -108,9 +104,8 @@ type Adapter struct {
 	doUpdateWithID  *calladapt.BoundCaller
 	waitAfterCreate *calladapt.BoundCaller
 	waitAfterUpdate *calladapt.BoundCaller
-	classifyChanges *calladapt.BoundCaller
 
-	recreateFields map[string]struct{}
+	fieldTriggers map[string]deployplan.ActionType
 }
 
 func NewAdapter(typedNil any, client *databricks.WorkspaceClient) (*Adapter, error) {
@@ -135,29 +130,28 @@ func NewAdapter(typedNil any, client *databricks.WorkspaceClient) (*Adapter, err
 		doUpdateWithID:  nil,
 		waitAfterCreate: nil,
 		waitAfterUpdate: nil,
-		classifyChanges: nil,
-		recreateFields:  map[string]struct{}{},
+		fieldTriggers:   map[string]deployplan.ActionType{},
 	}
 
 	err = adapter.initMethods(impl)
 	if err != nil {
 		return nil, err
 	}
 
-	// Load optional RecreateFields method from the unified interface
-	recreateCall, err := calladapt.PrepareCall(impl, calladapt.TypeOf[IResource](), "RecreateFields")
+	// Load optional FieldTriggers method from the unified interface
+	triggerCall, err := calladapt.PrepareCall(impl, calladapt.TypeOf[IResource](), "FieldTriggers")
 	if err != nil {
 		return nil, err
 	}
-	if recreateCall != nil {
-		outs, err := recreateCall.Call()
+	if triggerCall != nil {
+		outs, err := triggerCall.Call()
 		if err != nil || len(outs) != 1 {
-			return nil, fmt.Errorf("failed to call RecreateFields: %w", err)
+			return nil, fmt.Errorf("failed to call FieldTriggers: %w", err)
 		}
-		fields := outs[0].([]string)
-		adapter.recreateFields = make(map[string]struct{}, len(fields))
-		for _, field := range fields {
-			adapter.recreateFields[field] = struct{}{}
+		fields := outs[0].(map[string]deployplan.ActionType)
+		adapter.fieldTriggers = make(map[string]deployplan.ActionType, len(fields))
+		for k, v := range fields {
+			adapter.fieldTriggers[k] = v
 		}
 	}
 
@@ -217,8 +211,7 @@ func (a *Adapter) initMethods(resource any) error {
 		return err
 	}
 
-	a.classifyChanges, err = calladapt.PrepareCall(resource, calladapt.TypeOf[IResource](), "ClassifyChanges")
-	return err
+	return nil
 }
 
 // validateTypes validates type matches for variadic triples of (name, actual, expected).
@@ -293,8 +286,18 @@ func (a *Adapter) validate() error {
 		return err
 	}
 
-	if a.doUpdateWithID != nil && a.classifyChanges == nil {
-		return errors.New("if DoUpdateWithID is present, should have implement ClassifyChanges")
+	// FieldTriggers validation
+	hasUpdateWithIDTrigger := false
+	for _, action := range a.fieldTriggers {
+		if action == deployplan.ActionTypeUpdateWithID {
+			hasUpdateWithIDTrigger = true
+		}
+	}
+	if hasUpdateWithIDTrigger && a.doUpdateWithID == nil {
+		return errors.New("FieldTriggers includes update_with_id but DoUpdateWithID is not implemented")
+	}
+	if a.doUpdateWithID != nil && !hasUpdateWithIDTrigger {
+		return errors.New("DoUpdateWithID is implemented but FieldTriggers lacks update_with_id trigger")
 	}
 
 	return nil
@@ -381,11 +384,6 @@ func (a *Adapter) DoUpdate(ctx context.Context, id string, newState any) (any, e
 	}
 }
 
-// HasClassifyChanges returns true if the resource implements ClassifyChanges method.
-func (a *Adapter) HasClassifyChanges() bool {
-	return a.classifyChanges != nil
-}
-
 // HasDoUpdateWithID returns true if the resource implements DoUpdateWithID method.
 func (a *Adapter) HasDoUpdateWithID() bool {
 	return a.doUpdateWithID != nil
@@ -412,30 +410,26 @@ func (a *Adapter) DoUpdateWithID(ctx context.Context, oldID string, newState any
 	}
 }
 
-// MustRecreate checks if any of the changes require resource recreation.
-func (a *Adapter) MustRecreate(changes []structdiff.Change) bool {
-	if len(a.recreateFields) == 0 {
-		return false
+// ClassifyByTriggers classifies a set of changes using FieldTriggers.
+// Unspecified changed fields default to ActionTypeUpdate. Final action is the
+// maximum by precedence. No changes yield ActionTypeNoop.
+func (a *Adapter) ClassifyByTriggers(changes []structdiff.Change) deployplan.ActionType {
+	if len(changes) == 0 {
+		return deployplan.ActionTypeNoop
 	}
+
+	// Default when there are changes but no explicit trigger is update.
+	result := deployplan.ActionTypeUpdate
 	for _, change := range changes {
-		if _, ok := a.recreateFields[change.Path.String()]; ok {
-			return true
+		action, ok := a.fieldTriggers[change.Path.String()]
+		if !ok {
+			action = deployplan.ActionTypeUpdate
+		}
+		if action > result {
+			result = action
 		}
 	}
-	return false
-}
-
-// ClassifyChanges calls the resource's ClassifyChanges method if implemented.
-func (a *Adapter) ClassifyChanges(changes []structdiff.Change) (deployplan.ActionType, error) {
-	if a.classifyChanges == nil {
-		return deployplan.ActionTypeUnset, errors.New("internal error: ClassifyChanges not implemented")
-	}
-	outs, err := a.classifyChanges.Call(changes)
-	if err != nil {
-		return deployplan.ActionTypeUnset, err
-	}
-	result := outs[0].(deployplan.ActionType)
-	return result, nil
+	return result
 }
 
 // WaitAfterCreate waits for the resource to become ready after creation.

bundle/terranova/tnresources/all_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/databricks/cli/bundle/config/resources"
+	"github.com/databricks/cli/bundle/deployplan"
 	"github.com/databricks/cli/libs/structdiff/structpath"
 	"github.com/databricks/cli/libs/structwalk"
 	"github.com/databricks/cli/libs/testserver"
@@ -155,7 +156,7 @@ func testCRUD(t *testing.T, group string, adapter *Adapter, client *databricks.W
 }
 
 // validateFields uses structwalk to generate all valid field paths and checks membership.
-func validateFields(t *testing.T, configType reflect.Type, fields map[string]struct{}) {
+func validateFields(t *testing.T, configType reflect.Type, fields map[string]deployplan.ActionType) {
 	validPaths := make(map[string]struct{})
 
 	err := structwalk.WalkType(configType, func(path *structpath.PathNode, typ reflect.Type) bool {
@@ -171,15 +172,15 @@ func validateFields(t *testing.T, configType reflect.Type, fields map[string]str
 	}
 }
 
-// TestRecreateFields validates that all fields in RecreateFields
+// TestFieldTriggers validates that all trigger keys
 // exist in the corresponding ConfigType for each resource.
-func TestRecreateFields(t *testing.T) {
+func TestFieldTriggers(t *testing.T) {
 	for resourceName, resource := range SupportedResources {
 		adapter, err := NewAdapter(resource, nil)
 		require.NoError(t, err)
 
 		t.Run(resourceName, func(t *testing.T) {
-			validateFields(t, adapter.InputConfigType(), adapter.recreateFields)
+			validateFields(t, adapter.InputConfigType(), adapter.fieldTriggers)
 		})
 	}
 }

bundle/terranova/tnresources/app.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/databricks/cli/bundle/config/resources"
+	"github.com/databricks/cli/bundle/deployplan"
 	"github.com/databricks/cli/libs/log"
 	"github.com/databricks/databricks-sdk-go"
 	"github.com/databricks/databricks-sdk-go/retries"
@@ -63,9 +64,9 @@ func (r *ResourceApp) DoDelete(ctx context.Context, id string) error {
 	return err
 }
 
-func (*ResourceApp) RecreateFields() []string {
-	return []string{
-		".name",
+func (*ResourceApp) FieldTriggers() map[string]deployplan.ActionType {
+	return map[string]deployplan.ActionType{
+		".name": deployplan.ActionTypeRecreate,
 	}
 }
 

bundle/terranova/tnresources/pipeline.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/databricks/cli/bundle/config/resources"
+	"github.com/databricks/cli/bundle/deployplan"
 	"github.com/databricks/databricks-sdk-go"
 	"github.com/databricks/databricks-sdk-go/service/pipelines"
 )
@@ -77,12 +78,12 @@ func (r *ResourcePipeline) DoDelete(ctx context.Context, id string) error {
 	return r.client.Pipelines.DeleteByPipelineId(ctx, id)
 }
 
-func (*ResourcePipeline) RecreateFields() []string {
-	return []string{
-		".storage",
-		".catalog",
-		".ingestion_definition.connection_name",
-		".ingestion_definition.ingestion_gateway_id",
+func (*ResourcePipeline) FieldTriggers() map[string]deployplan.ActionType {
+	return map[string]deployplan.ActionType{
+		".storage":                              deployplan.ActionTypeRecreate,
+		".catalog":                              deployplan.ActionTypeRecreate,
+		".ingestion_definition.connection_name": deployplan.ActionTypeRecreate,
+		".ingestion_definition.ingestion_gateway_id": deployplan.ActionTypeRecreate,
 	}
 }
 

bundle/terranova/tnresources/schema.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/databricks/cli/bundle/config/resources"
+	"github.com/databricks/cli/bundle/deployplan"
 	"github.com/databricks/cli/libs/log"
 	"github.com/databricks/databricks-sdk-go"
 	"github.com/databricks/databricks-sdk-go/service/catalog"
@@ -65,10 +66,10 @@ func (r *ResourceSchema) DoDelete(ctx context.Context, id string) error {
 	})
 }
 
-func (*ResourceSchema) RecreateFields() []string {
-	return []string{
-		".name",
-		".catalog_name",
-		".storage_root",
+func (*ResourceSchema) FieldTriggers() map[string]deployplan.ActionType {
+	return map[string]deployplan.ActionType{
+		".name":         deployplan.ActionTypeRecreate,
+		".catalog_name": deployplan.ActionTypeRecreate,
+		".storage_root": deployplan.ActionTypeRecreate,
 	}
 }

bundle/terranova/tnresources/volume.go

@@ -8,7 +8,6 @@ import (
 	"github.com/databricks/cli/bundle/config/resources"
 	"github.com/databricks/cli/bundle/deployplan"
 	"github.com/databricks/cli/libs/log"
-	"github.com/databricks/cli/libs/structdiff"
 	"github.com/databricks/databricks-sdk-go"
 	"github.com/databricks/databricks-sdk-go/service/catalog"
 )
@@ -101,24 +100,16 @@ func (r *ResourceVolume) DoDelete(ctx context.Context, id string) error {
 	return r.client.Volumes.DeleteByName(ctx, id)
 }
 
-func (*ResourceVolume) RecreateFields() []string {
-	return []string{
-		".catalog_name",
-		".schema_name",
-		".storage_location",
-		".volume_type",
+func (*ResourceVolume) FieldTriggers() map[string]deployplan.ActionType {
+	return map[string]deployplan.ActionType{
+		".catalog_name":     deployplan.ActionTypeRecreate,
+		".schema_name":      deployplan.ActionTypeRecreate,
+		".storage_location": deployplan.ActionTypeRecreate,
+		".volume_type":      deployplan.ActionTypeRecreate,
+		".name":             deployplan.ActionTypeUpdateWithID,
 	}
 }
 
-func (r *ResourceVolume) ClassifyChanges(changes []structdiff.Change) deployplan.ActionType {
-	for _, change := range changes {
-		if change.Path.String() == ".name" {
-			return deployplan.ActionTypeUpdateWithID
-		}
-	}
-	return deployplan.ActionTypeUpdate
-}
-
 func getNameFromID(id string) (string, error) {
 	items := strings.Split(id, ".")
 	if len(items) == 0 {