fix(table-core): don't fire onExpandedChange when resetExpanded is a no-op

.changeset/reset-expanded-noop.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/table-core': patch
+---
+
+Make `table.resetExpanded()` a no-op when the target state already matches the current expanded state, so it no longer fires `onExpandedChange` with a new-but-equal map. `row.toggleExpanded()` and `table.toggleAllRowsExpanded()` already early-return this way. Because the core row model auto-resets `expanded` on every `data` reference change, the unguarded write could drive a controlled table with an unstable `data` reference into an unbounded render loop.

docs/reference/static-functions/functions/row_getCanExpand.md

@@ -9,7 +9,7 @@ title: row_getCanExpand
 function row_getCanExpand<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:378](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L378)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:399](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L399)
 
 Checks whether this row can be expanded.
 

docs/reference/static-functions/functions/row_getIsAllParentsExpanded.md

@@ -9,7 +9,7 @@ title: row_getIsAllParentsExpanded
 function row_getIsAllParentsExpanded<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:398](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L398)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:419](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L419)
 
 Checks whether every ancestor of this row is expanded.
 

docs/reference/static-functions/functions/row_getIsExpanded.md

@@ -9,7 +9,7 @@ title: row_getIsExpanded
 function row_getIsExpanded<TFeatures, TData>(row): boolean;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:343](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L343)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:364](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L364)
 
 Checks whether this row is expanded.
 

docs/reference/static-functions/functions/row_getToggleExpandedHandler.md

@@ -9,7 +9,7 @@ title: row_getToggleExpandedHandler
 function row_getToggleExpandedHandler<TFeatures, TData>(row): () => void;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:423](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L423)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:444](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L444)
 
 Creates a row control handler that toggles this row's expanded state.
 

docs/reference/static-functions/functions/row_toggleExpanded.md

@@ -9,7 +9,7 @@ title: row_toggleExpanded
 function row_toggleExpanded<TFeatures, TData>(row, expanded?): void;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:284](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L284)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:305](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L305)
 
 Expands or collapses this row.
 

docs/reference/static-functions/functions/table_getCanSomeRowsExpand.md

@@ -9,7 +9,7 @@ title: table_getCanSomeRowsExpand
 function table_getCanSomeRowsExpand<TFeatures, TData>(table): boolean;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:145](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L145)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:166](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L166)
 
 Checks whether at least one pre-paginated row can expand.
 

docs/reference/static-functions/functions/table_getExpandedDepth.md

@@ -9,7 +9,7 @@ title: table_getExpandedDepth
 function table_getExpandedDepth<TFeatures, TData>(table): number;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:245](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L245)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:266](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L266)
 
 Computes the deepest expanded row id depth.
 

docs/reference/static-functions/functions/table_getIsAllRowsExpanded.md

@@ -9,7 +9,7 @@ title: table_getIsAllRowsExpanded
 function table_getIsAllRowsExpanded<TFeatures, TData>(table): boolean;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:202](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L202)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:223](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L223)
 
 Checks whether every expandable row in the current row model is expanded.
 

docs/reference/static-functions/functions/table_getIsSomeRowsExpanded.md

@@ -9,7 +9,7 @@ title: table_getIsSomeRowsExpanded
 function table_getIsSomeRowsExpanded<TFeatures, TData>(table): boolean;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:181](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L181)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:202](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L202)
 
 Checks whether any row is expanded.
 

docs/reference/static-functions/functions/table_getToggleAllRowsExpandedHandler.md

@@ -9,7 +9,7 @@ title: table_getToggleAllRowsExpandedHandler
 function table_getToggleAllRowsExpandedHandler<TFeatures, TData>(table): (_e) => void;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:162](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L162)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:183](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L183)
 
 Creates an event handler that toggles all rows expanded.
 

docs/reference/static-functions/functions/table_resetExpanded.md

@@ -9,13 +9,17 @@ title: table_resetExpanded
 function table_resetExpanded<TFeatures, TData>(table, defaultState?): void;
 ```
 
-Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:116](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L116)
+Defined in: [features/row-expanding/rowExpandingFeature.utils.ts:120](https://github.com/TanStack/table/blob/main/packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts#L120)
 
 Resets `expanded` to the configured initial state or feature default.
 
 With no argument, the reset clones `table.initialState.expanded` when it
 exists. Passing `true` ignores initial state and resets to `{}`.
 
+The call is a no-op (no `onExpandedChange`) when the target state already
+matches the current state, so an auto-reset on a table with nothing expanded
+does not publish a new-but-equal map.
+
 ## Type Parameters
 
 ### TFeatures

packages/table-core/src/features/row-expanding/rowExpandingFeature.utils.ts

@@ -107,6 +107,10 @@ export function table_toggleAllRowsExpanded<
  * With no argument, the reset clones `table.initialState.expanded` when it
  * exists. Passing `true` ignores initial state and resets to `{}`.
  *
+ * The call is a no-op (no `onExpandedChange`) when the target state already
+ * matches the current state, so an auto-reset on a table with nothing expanded
+ * does not publish a new-but-equal map.
+ *
  * @example
  * ```ts
  * table_resetExpanded(table)
@@ -117,18 +121,35 @@ export function table_resetExpanded<
   TFeatures extends TableFeatures,
   TData extends RowData,
 >(table: Table_Internal<TFeatures, TData>, defaultState?: boolean) {
+  const currentExpanded = table.atoms.expanded?.get() ?? {}
   const initialExpanded = table.initialState.expanded
-  table_setExpanded(
-    table,
-    defaultState
-      ? makeObjectMap()
-      : initialExpanded === true
-        ? true
-        : Object.assign(
-            makeObjectMap<boolean | undefined>(),
-            cloneState(initialExpanded ?? {}),
-          ),
-  )
+  const newExpanded: ExpandedState = defaultState
+    ? makeObjectMap()
+    : initialExpanded === true
+      ? true
+      : Object.assign(
+          makeObjectMap<boolean | undefined>(),
+          cloneState(initialExpanded ?? {}),
+        )
+
+  if (isSameExpandedState(currentExpanded, newExpanded)) return
+
+  table_setExpanded(table, newExpanded)
+}
+
+function isSameExpandedState(a: ExpandedState, b: ExpandedState): boolean {
+  if (a === true || b === true) return a === b
+
+  const aKeys = Object.keys(a)
+
+  if (aKeys.length !== Object.keys(b).length) return false
+
+  for (let i = 0; i < aKeys.length; i++) {
+    const key = aKeys[i]!
+    if (!hasOwn(b, key) || a[key] !== b[key]) return false
+  }
+
+  return true
 }
 
 /**

packages/table-core/tests/unit/features/row-expanding/rowExpandingFeature.utils.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it, vi } from 'vitest'
 import {
   constructTable,
   createExpandedRowModel,
+  functionalUpdate,
   rowExpandingFeature,
 } from '../../../../src'
 import {
@@ -25,7 +26,12 @@ import { testFeatures } from '../../../fixtures/features'
 import { generateTestColumnDefs } from '../../../fixtures/data/generateTestColumnDefs'
 import { generateTestData } from '../../../fixtures/data/generateTestData'
 import { getUpdaterResult } from '../../../helpers/testUtils'
-import type { ExpandedState, Table, TableOptions } from '../../../../src'
+import type {
+  ExpandedState,
+  Table,
+  TableOptions,
+  Updater,
+} from '../../../../src'
 import type { Person } from '../../../fixtures/data/types'
 
 const features = testFeatures({
@@ -88,6 +94,7 @@ describe('table_resetExpanded', () => {
       onExpandedChange,
       initialState: { expanded: { '0': true } },
     })
+    table.baseAtoms.expanded.set({ '0': true, '1': true })
 
     table_resetExpanded(table)
 
@@ -100,11 +107,67 @@ describe('table_resetExpanded', () => {
       onExpandedChange,
       initialState: { expanded: true },
     })
+    table.baseAtoms.expanded.set({ '0': true })
 
     table_resetExpanded(table)
 
     expect(onExpandedChange).toHaveBeenCalledWith(true)
   })
+
+  it('should reset when the expanded ids differ at the same count', () => {
+    const onExpandedChange = vi.fn()
+    const table = makeTable({
+      onExpandedChange,
+      initialState: { expanded: { '0': true } },
+    })
+    table.baseAtoms.expanded.set({ '1': true })
+
+    table_resetExpanded(table)
+
+    expect(onExpandedChange).toHaveBeenCalledWith({ '0': true })
+  })
+
+  it('should be a no-op when nothing is expanded', () => {
+    const onExpandedChange = vi.fn()
+    const table = makeTable({ onExpandedChange })
+
+    table_resetExpanded(table)
+
+    expect(onExpandedChange).not.toHaveBeenCalled()
+  })
+
+  it('should be a no-op when the expanded map is already at the target', () => {
+    const onExpandedChange = vi.fn()
+    const table = makeTable({
+      onExpandedChange,
+      initialState: { expanded: { '0': true } },
+    })
+
+    table_resetExpanded(table)
+
+    expect(onExpandedChange).not.toHaveBeenCalled()
+  })
+
+  it('should be a no-op when already in the expanded-all initial state', () => {
+    const onExpandedChange = vi.fn()
+    const table = makeTable({
+      onExpandedChange,
+      initialState: { expanded: true },
+    })
+
+    table_resetExpanded(table)
+
+    expect(onExpandedChange).not.toHaveBeenCalled()
+  })
+
+  it('should be a no-op when defaultState is true and nothing is expanded', () => {
+    const onExpandedChange = vi.fn()
+    const table = makeTable({ onExpandedChange })
+
+    table_resetExpanded(table, true)
+
+    expect(onExpandedChange).not.toHaveBeenCalled()
+  })
 })
 
 describe('table_toggleAllRowsExpanded', () => {
@@ -538,4 +601,32 @@ describe('table_autoResetExpanded', () => {
 
     expect(onExpandedChange).not.toHaveBeenCalled()
   })
+
+  it('should not loop when a data identity change resets controlled state that already matches', async () => {
+    // Stands in for a framework render loop: the auto-reset publishes expanded
+    // state, the consumer re-renders with a fresh `data` reference, and the core
+    // row model recomputes and auto-resets again
+    let expanded: ExpandedState = {}
+    let table: Table<typeof features, Person>
+    const onExpandedChange = vi.fn((updater: Updater<ExpandedState>) => {
+      expanded = functionalUpdate(updater, expanded)
+      // stop feeding the loop so a regression fails the assertion below
+      // instead of hanging the suite
+      if (onExpandedChange.mock.calls.length > 5) return
+      table.setOptions((prev) => ({
+        ...prev,
+        data: [...prev.data],
+        state: { ...prev.state, expanded },
+      }))
+      table.getCoreRowModel()
+    })
+    table = makeTable({ state: { expanded }, onExpandedChange })
+    table.getCoreRowModel()
+
+    table.setOptions((prev) => ({ ...prev, data: [...prev.data] }))
+    table.getCoreRowModel()
+    await flushMicrotasks()
+
+    expect(onExpandedChange).not.toHaveBeenCalled()
+  })
 })