From be49605f871881eae98b0b0dea55743adde1b9d1 Mon Sep 17 00:00:00 2001
From: fuzmish <71511927+fuzmish@users.noreply.github.com>
Date: Sat, 1 Aug 2026 06:29:58 +0900
Subject: [PATCH] Fix incremental table compilation failing on
 metadata.extraProperties

---
 common/protos/index.ts                 |  8 ++--
 core/actions/incremental_table.ts      |  8 +++-
 core/actions/incremental_table_test.ts | 63 ++++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 4 deletions(-)

diff --git a/common/protos/index.ts b/common/protos/index.ts
index 2bf2777b2..7d34336bb 100644
--- a/common/protos/index.ts
+++ b/common/protos/index.ts
@@ -33,8 +33,7 @@ const Struct = google.protobuf.Struct;
 // Save references to the original generated methods
 const originalVerify = Struct.verify;
 
-// Monkey Patching Methods
-Struct.verify = function (object: any) {
+export function verifyStruct(this: any, object: any) {
   if (object && typeof object === "object" && !("fields" in object)) {
     const fields: { [key: string]: any } = {};
     for (const [k, v] of Object.entries(object)) {
@@ -44,7 +43,10 @@ Struct.verify = function (object: any) {
     object.fields = fields;
   }
   return originalVerify.call(this, object);
-};
+}
+
+// Monkey Patching Methods
+Struct.verify = verifyStruct;
 
 // This is a minimalist Typescript equivalent for the validation part of Profobuf's JsonFormat's
 // mergeMessage method:
diff --git a/core/actions/incremental_table.ts b/core/actions/incremental_table.ts
index 3ae9560f8..6fb5ab8c0 100644
--- a/core/actions/incremental_table.ts
+++ b/core/actions/incremental_table.ts
@@ -1,4 +1,4 @@
-import { verifyObjectMatchesProto, VerifyProtoErrorBehaviour } from "df/common/protos";
+import { verifyObjectMatchesProto, VerifyProtoErrorBehaviour, verifyStruct } from "df/common/protos";
 import {
   ActionBuilder,
   checkConfigAdditionalOptionsOverlap,
@@ -692,6 +692,12 @@ export class IncrementalTable extends ActionBuilder<dataform.Table> {
       }
     }
 
+    // Since IncrementalTableConfig.metadata.extraProperties expects IMetadata,
+    // we will normalize the expression into google.protobuf.IStruct here.
+    if (unverifiedConfig.metadata?.extraProperties) {
+      verifyStruct(unverifiedConfig.metadata.extraProperties);
+    }
+
     const config = verifyObjectMatchesProto(
       dataform.ActionConfig.IncrementalTableConfig,
       unverifiedConfig,
diff --git a/core/actions/incremental_table_test.ts b/core/actions/incremental_table_test.ts
index b80ceab43..c08cd21bc 100644
--- a/core/actions/incremental_table_test.ts
+++ b/core/actions/incremental_table_test.ts
@@ -211,6 +211,69 @@ SELECT 1`
       });
     });
 
+    test("onSchemaChange combined with metadata.extraProperties as a plain object", () => {
+      const tableName = "on_schema_change_with_metadata";
+      const tableContent = `
+config {
+  type: "incremental",
+  onSchemaChange: "IGNORE",
+  metadata: {
+    extraProperties: {
+      myField: "example"
+    }
+  }
+}
+
+SELECT 1`;
+      const projectDir = tmpDirFixture.createNewTmpDir();
+      fs.writeFileSync(
+        path.join(projectDir, "workflow_settings.yaml"),
+        VALID_WORKFLOW_SETTINGS_YAML
+      );
+      fs.mkdirSync(path.join(projectDir, "definitions"));
+      fs.writeFileSync(
+        path.join(projectDir, `definitions/${tableName}.sqlx`),
+        tableContent
+      );
+
+      const result = runMainInVm(coreExecutionRequestFromPath(projectDir));
+
+      expect(result.compile.compiledGraph.graphErrors.compilationErrors).deep.equals([]);
+      expect(asPlainObject(result.compile.compiledGraph.tables)).deep.equals([
+        {
+          target: {
+            database: "defaultProject",
+            schema: "defaultDataset",
+            name: tableName
+          },
+          canonicalTarget: {
+            database: "defaultProject",
+            schema: "defaultDataset",
+            name: tableName
+          },
+          type: "incremental",
+          disabled: false,
+          protected: false,
+          hermeticity: "NON_HERMETIC",
+          onSchemaChange: "IGNORE",
+          enumType: "INCREMENTAL",
+          fileName: `definitions/${tableName}.sqlx`,
+          query: "\n\n\nSELECT 1",
+          incrementalQuery: "\n\n\nSELECT 1",
+          incrementalStrategy: "INCREMENTAL_STRATEGY_UNSPECIFIED",
+          actionDescriptor: {
+            metadata: {
+              extraProperties: {
+                fields: {
+                  myField: { stringValue: "example" }
+                }
+              }
+            }
+          }
+        }
+      ]);
+    });
+
     test("sqlx minimal config", () => {
       const minimalIncrementalTableName = "minimal_incremental";
       const minimalIncrementalTableContent = `