Merging table.columns for dashcards (#35259)

* temp

* Adding unit test

frontend/src/metabase/visualizations/lib/settings.js

@@ -243,9 +243,34 @@ export function mergeSettings(first = {}, second = {}) {
       }
     }
   }
+
+  if (first["table.columns"] && second["table.columns"]) {
+    merged["table.columns"] = mergeTableColumns(
+      first["table.columns"],
+      second["table.columns"],
+    );
+  }
+
   return merged;
 }
 
+const mergeTableColumns = (firstTableColumns, secondTableColumns) => {
+  const addedColumns = firstTableColumns.filter(
+    ({ name }) => secondTableColumns.findIndex(col => col.name === name) === -1,
+  );
+  const removedColumns = secondTableColumns
+    .filter(
+      ({ name }) =>
+        firstTableColumns.findIndex(col => col.name === name) === -1,
+    )
+    .map(({ name }) => name);
+
+  return [
+    ...secondTableColumns.filter(({ name }) => !removedColumns.includes(name)),
+    ...addedColumns,
+  ];
+};
+
 export function getClickBehaviorSettings(settings) {
   const newSettings = {};
 

frontend/src/metabase/visualizations/lib/settings.unit.spec.js

+import { ORDERS } from "metabase-types/api/mocks/presets";
+import { createMockTableColumnOrderSetting } from "metabase-types/api/mocks";
+
 // NOTE: need to load visualizations first for getSettings to work
 import "metabase/visualizations/index";
 
@@ -196,6 +199,81 @@ describe("settings framework", () => {
         mergeSettings({}, { column_settings: { col1: { set1: "val" } } }),
       ).toEqual({ column_settings: { col1: { set1: "val" } } });
     });
+
+    describe("table.columns", () => {
+      const ID_COLUMN = createMockTableColumnOrderSetting({
+        name: "ID",
+        fieldRef: ["field", ORDERS.ID, null],
+      });
+
+      const QUANTITY_COLUMN = createMockTableColumnOrderSetting({
+        name: "QUANTITY",
+        fieldRef: ["field", ORDERS.QUANTITY, null],
+      });
+
+      const TAX_COLUMN = createMockTableColumnOrderSetting({
+        name: "TAX",
+        fieldRef: ["field", ORDERS.TAX, null],
+      });
+
+      const DISCOUNT_COLUMN = createMockTableColumnOrderSetting({
+        name: "DISCOUNT",
+        fieldRef: ["field", ORDERS.DISCOUNT, null],
+      });
+
+      it("should remove columns that don't appear in the first settings", () => {
+        expect(
+          mergeSettings(
+            {
+              "table.columns": [ID_COLUMN, QUANTITY_COLUMN],
+            },
+            {
+              "table.columns": [ID_COLUMN, QUANTITY_COLUMN, TAX_COLUMN],
+            },
+          ),
+        ).toEqual({
+          "table.columns": [ID_COLUMN, QUANTITY_COLUMN],
+        });
+      });
+      it("should add new columns that don't appear in the second settings", () => {
+        expect(
+          mergeSettings(
+            {
+              "table.columns": [ID_COLUMN, QUANTITY_COLUMN, DISCOUNT_COLUMN],
+            },
+            {
+              "table.columns": [ID_COLUMN, QUANTITY_COLUMN],
+            },
+          ),
+        ).toEqual({
+          "table.columns": [ID_COLUMN, QUANTITY_COLUMN, DISCOUNT_COLUMN],
+        });
+      });
+
+      it("should preserve settings and order from the second settings", () => {
+        expect(
+          mergeSettings(
+            {
+              "table.columns": [ID_COLUMN, QUANTITY_COLUMN, DISCOUNT_COLUMN],
+            },
+            {
+              "table.columns": [
+                DISCOUNT_COLUMN,
+                { ...ID_COLUMN, enabled: false },
+                QUANTITY_COLUMN,
+                TAX_COLUMN,
+              ],
+            },
+          ),
+        ).toEqual({
+          "table.columns": [
+            DISCOUNT_COLUMN,
+            { ...ID_COLUMN, enabled: false },
+            QUANTITY_COLUMN,
+          ],
+        });
+      });
+    });
   });
 
   describe("getClickBehaviorSettings", () => {