fix(diff): support auto fields (#136)

* fix(diff): support auto fields

call the new utils function FillPluginsDefaultsAutoFields from  go-kong
to ensure auto fields are considered when doing the diff

* fix(crud): detect operation correctly

fixes a bug that was introduced in
e72f4c2 where noops were still detected
as updates. That happened because of a check happening in plugin.go that
detected the crud operation based on a diff.
When done without considering default/auto fields, this check would see
differences where there were none. This resulted in unnecessary updates
to the DB and wrong diff strings during `sync` and `diff`.

This commit adds defaults/auto fields to the configuration used for that
diff.

* pr review suggestions

pkg/diff/diff.go

@@ -609,10 +609,7 @@ func (sc *Syncer) Solve(ctx context.Context, parallelism int, dry bool, isJSONOu
 		// that will be used for the diff. This is needed to avoid highlighting
 		// default values that were populated by Kong as differences.
 		if plugin, ok := e.Obj.(*state.Plugin); ok {
-			pluginCopy := &state.Plugin{
-				Plugin: *plugin.DeepCopy(),
-				Meta:   plugin.Meta,
-			}
+			pluginCopy := &state.Plugin{Plugin: *plugin.DeepCopy()}
 			e.Obj = pluginCopy
 
 			exists, err := utils.WorkspaceExists(ctx, sc.kongClient)
@@ -623,8 +620,13 @@ func (sc *Syncer) Solve(ctx context.Context, parallelism int, dry bool, isJSONOu
 					return nil, err
 				}
 
-				if err := kong.FillPluginsDefaults(&pluginCopy.Plugin, schema); err != nil {
-					return nil, fmt.Errorf("failed filling plugin defaults: %w", err)
+				var oldPlugin *kong.Plugin
+				if kongStatePlugin, ok := e.OldObj.(*state.Plugin); ok {
+					oldPlugin = &kongStatePlugin.Plugin
+				}
+				newPlugin := &pluginCopy.Plugin
+				if err := kong.FillPluginsDefaultsAutoFields(newPlugin, schema, oldPlugin); err != nil {
+					return nil, fmt.Errorf("failed processing auto fields: %w", err)
 				}
 			}
 		}

pkg/types/core.go

@@ -232,6 +232,7 @@ func NewEntity(t EntityType, opts EntityOpts) (Entity, error) {
 				kind:         entityTypeToKind(Plugin),
 				currentState: opts.CurrentState,
 				targetState:  opts.TargetState,
+				kongClient:   opts.KongClient,
 			},
 		}, nil
 	case Consumer:

pkg/types/plugin.go

@@ -88,6 +88,7 @@ type pluginDiffer struct {
 	kind crud.Kind
 
 	currentState, targetState *state.KongState
+	kongClient                *kong.Client
 }
 
 func (d *pluginDiffer) Deletes(handler func(crud.Event) error) error {
@@ -174,8 +175,18 @@ func (d *pluginDiffer) createUpdatePlugin(plugin *state.Plugin) (*crud.Event, er
 	}
 	currentPlugin = &state.Plugin{Plugin: *currentPlugin.DeepCopy()}
 	// found, check if update needed
+	// before checking the diff, fill in the defaults
+	schema, err := d.kongClient.Plugins.GetFullSchema(context.TODO(), plugin.Name)
+	if err != nil {
+		return nil, fmt.Errorf("failed getting schema: %w", err)
+	}
+	pluginWithDefaults := &state.Plugin{Plugin: *plugin.DeepCopy()}
+	err = kong.FillPluginsDefaultsAutoFields(&pluginWithDefaults.Plugin, schema, &currentPlugin.Plugin)
+	if err != nil {
+		return nil, fmt.Errorf("failed processing auto fields: %w", err)
+	}
 
-	if !currentPlugin.EqualWithOpts(plugin, false, true, false) {
+	if !currentPlugin.EqualWithOpts(pluginWithDefaults, false, true, false) {
 		return &crud.Event{
 			Op:     crud.Update,
 			Kind:   d.kind,

tests/integration/sync_test.go

@@ -15,6 +15,7 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"os"
+	"regexp"
 	"strings"
 	"testing"
 	"time"
@@ -5627,3 +5628,61 @@ func Test_Sync_PluginDoNotFillDefaults(t *testing.T) {
 		})
 	})
 }
+
+func Test_Sync_PluginAutoFields(t *testing.T) {
+	client, err := getTestClient()
+
+	require.NoError(t, err)
+	ctx := context.Background()
+	t.Run("plugin_with_auto_fields", func(t *testing.T) {
+		mustResetKongState(ctx, t, client, deckDump.Config{})
+
+		currentState, err := fetchCurrentState(ctx, client, deckDump.Config{})
+		require.NoError(t, err)
+		targetState := stateFromFile(ctx, t,
+			"testdata/sync/034-fill-auto-oauth2/kong.yaml",
+			client,
+			deckDump.Config{},
+		)
+
+		kongURL, err := url.Parse(client.BaseRootURL())
+		require.NoError(t, err)
+		p := NewRecordRequestProxy(kongURL)
+		s := httptest.NewServer(p)
+		c, err := utils.GetKongClient(utils.KongClientConfig{
+			Address: s.URL,
+		})
+		require.NoError(t, err)
+
+		syncer, err := deckDiff.NewSyncer(deckDiff.SyncerOpts{
+			CurrentState: currentState,
+			TargetState:  targetState,
+
+			KongClient: c,
+		})
+		stats, errs, changes := syncer.Solve(ctx, 1, false, true)
+		require.Empty(t, errs, "Should have no errors in syncing")
+		require.NoError(t, err)
+
+		require.Equal(t, int32(1), stats.CreateOps.Count(), "Should create 1 entity")
+		require.Len(t, changes.Creating, 1, "Should have 1 creating record in changes")
+
+		t.Run("should not override auto values with nils", func(t *testing.T) {
+			newState, err := fetchCurrentState(ctx, client, deckDump.Config{})
+			require.NoError(t, err)
+			plugins, err := newState.Plugins.GetAll()
+			require.NoError(t, err)
+			require.Len(t, plugins, 1)
+			plugin := plugins[0]
+			require.Equal(t, "oauth2", *plugin.Name)
+			provisionKey, ok := plugin.Config["provision_key"]
+			require.True(t, ok)
+
+			provisionKeyStr, ok := provisionKey.(string)
+			require.True(t, ok, "provision_key is not a string")
+			pattern := `^[a-zA-Z0-9]+$`
+			re := regexp.MustCompile(pattern)
+			require.True(t, re.MatchString(provisionKeyStr), "provision_key does not match the pattern")
+		})
+	})
+}

tests/integration/testdata/sync/034-fill-auto-oauth2/kong.yaml

@@ -0,0 +1,5 @@
+_format_version: "3.0"
+plugins:
+  - name: oauth2
+    config:
+      enable_password_grant: true