fix(dashboard): required filters reliably apply default + Apply enables on change

Three small fixes for native filter state desync:

1. utils.ts — remove the selectedCount !== appliedCount early-return in
   checkIsApplyDisabled (regression from #37681). It disabled Apply whenever
   Selected had an entry Applied lacked — i.e. precisely when a user typed
   a value into a filter whose default never made it to Applied. dataEqual
   with ignoreUndefined already handles the "no real change" case correctly.

2. reducer.ts updateDataMaskForFilterChanges — only preserve existing
   filterState/extraFormData when there's actually a non-empty value.
   Previously, modifying a required filter would preserve empty existing
   state and wipe the newly defined default.

3. reducer.ts fillNativeFilters — on HYDRATE_DASHBOARD the shallow spread
   of the permalink-loaded dataMask wiped filter.defaultDataMask.filterState
   when the loaded mask was captured mid-initialization. Now defaults
   survive when the loaded mask lacks a real value.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: geido

superset-frontend/src/dashboard/components/nativeFilters/FilterBar/utils.test.ts

@@ -299,7 +299,10 @@ test('checkIsApplyDisabled returns true when required filter is missing value in
   );
 });
 
-test('checkIsApplyDisabled handles filter count mismatch', () => {
+test('checkIsApplyDisabled enables Apply when Selected has a filter value not yet in Applied', () => {
+  // Regression: when a required filter's default isn't applied (Applied missing
+  // the entry) and the user types a value, Selected gains an entry Applied
+  // doesn't have. Apply must be enabled so the user can commit the value.
   const dataMaskSelected: DataMaskStateWithId = {
     'filter-1': {
       id: 'filter-1',
@@ -322,7 +325,7 @@ test('checkIsApplyDisabled handles filter count mismatch', () => {
   const filters = [createFilter('filter-1'), createFilter('filter-2')];
 
   expect(checkIsApplyDisabled(dataMaskSelected, dataMaskApplied, filters)).toBe(
-    true,
+    false,
   );
 });
 

superset-frontend/src/dashboard/components/nativeFilters/FilterBar/utils.ts

@@ -74,13 +74,9 @@ export const checkIsApplyDisabled = (
   const selectedExtraFormData = getOnlyExtraFormData(dataMaskSelected);
   const appliedExtraFormData = getOnlyExtraFormData(dataMaskApplied);
 
-  // Check counts first
-  const selectedCount = Object.keys(selectedExtraFormData).length;
-  const appliedCount = Object.keys(appliedExtraFormData).length;
-
-  if (selectedCount !== appliedCount) return true;
-
-  // Check for changes
+  // Check for changes. ignoreUndefined drops empty keys on both sides so that
+  // a filter present in Selected with a real value but absent (or undefined)
+  // in Applied is correctly detected as a change.
   const dataEqual = areObjectsEqual(
     selectedExtraFormData,
     appliedExtraFormData,

superset-frontend/src/dataMask/reducer.ts

@@ -109,10 +109,33 @@ function fillNativeFilters(
 ) {
   filterConfig.forEach((filter: Filter) => {
     const dataMask = initialDataMask || {};
+    const loaded = dataMask[filter.id];
+
+    // The shallow spread of `loaded` would override `filter.defaultDataMask`
+    // even when `loaded.filterState` is empty (e.g. a permalink captured
+    // mid-initialization), wiping out a valid default. For REQUIRED filters
+    // with a default, fall back to the default when the loaded mask carries
+    // no real value. Non-required filters keep current behavior so a user's
+    // explicit clear isn't undone.
+    const isRequired = !!filter.controlValues?.enableEmptyFilter;
+    const loadedValue = loaded?.filterState?.value;
+    const loadedHasValue =
+      loadedValue !== undefined &&
+      loadedValue !== null &&
+      !(Array.isArray(loadedValue) && loadedValue.length === 0);
+    const shouldRestoreDefault =
+      isRequired && !loadedHasValue && !!filter.defaultDataMask;
+
     mergedDataMask[filter.id] = {
       ...getInitialDataMask(filter.id), // take initial data
       ...filter.defaultDataMask, // if something new came from BE - take it
-      ...dataMask[filter.id],
+      ...loaded,
+      ...(shouldRestoreDefault
+        ? {
+            filterState: filter.defaultDataMask?.filterState,
+            extraFormData: filter.defaultDataMask?.extraFormData,
+          }
+        : {}),
     };
     if (
       currentFilters &&
@@ -155,10 +178,18 @@ function updateDataMaskForFilterChanges(
     // Check if targets are equal
     const areTargetsEqual = isEqual(prevFilterDef?.targets, filter?.targets);
 
-    // Preserve state only if filter exists, has enableEmptyFilter=true and targets match
+    // Preserve state only when there's actually a value to preserve. Otherwise
+    // the empty existing state would wipe the (possibly newly-defined) default.
+    const existingValue = existingFilter?.filterState?.value;
+    const hasExistingValue =
+      existingValue !== undefined &&
+      existingValue !== null &&
+      !(Array.isArray(existingValue) && existingValue.length === 0);
+
     const shouldPreserveState =
       existingFilter &&
       areTargetsEqual &&
+      hasExistingValue &&
       (filter.controlValues?.enableEmptyFilter ||
         filter.controlValues?.defaultToFirstItem);