Index: node_modules/reselect/src/devModeChecks/inputStabilityCheck.ts
===================================================================
--- node_modules/reselect/src/devModeChecks/inputStabilityCheck.ts	(revision a762898ecd37a452c782821d4c2c4955c6ed2521)
+++ node_modules/reselect/src/devModeChecks/inputStabilityCheck.ts	(revision a762898ecd37a452c782821d4c2c4955c6ed2521)
@@ -0,0 +1,59 @@
+import type { CreateSelectorOptions, UnknownMemoizer } from '../types'
+
+/**
+ * Runs a stability check to ensure the input selector results remain stable
+ * when provided with the same arguments. This function is designed to detect
+ * changes in the output of input selectors, which can impact the performance of memoized selectors.
+ *
+ * @param inputSelectorResultsObject - An object containing two arrays: `inputSelectorResults` and `inputSelectorResultsCopy`, representing the results of input selectors.
+ * @param options - Options object consisting of a `memoize` function and a `memoizeOptions` object.
+ * @param inputSelectorArgs - List of arguments being passed to the input selectors.
+ *
+ * @see {@link https://reselect.js.org/api/development-only-stability-checks/#inputstabilitycheck `inputStabilityCheck`}
+ *
+ * @since 5.0.0
+ * @internal
+ */
+export const runInputStabilityCheck = (
+  inputSelectorResultsObject: {
+    inputSelectorResults: unknown[]
+    inputSelectorResultsCopy: unknown[]
+  },
+  options: Required<
+    Pick<
+      CreateSelectorOptions<UnknownMemoizer, UnknownMemoizer>,
+      'memoize' | 'memoizeOptions'
+    >
+  >,
+  inputSelectorArgs: unknown[] | IArguments
+) => {
+  const { memoize, memoizeOptions } = options
+  const { inputSelectorResults, inputSelectorResultsCopy } =
+    inputSelectorResultsObject
+  const createAnEmptyObject = memoize(() => ({}), ...memoizeOptions)
+  // if the memoize method thinks the parameters are equal, these *should* be the same reference
+  const areInputSelectorResultsEqual =
+    createAnEmptyObject.apply(null, inputSelectorResults) ===
+    createAnEmptyObject.apply(null, inputSelectorResultsCopy)
+  if (!areInputSelectorResultsEqual) {
+    let stack: string | undefined = undefined
+    try {
+      throw new Error()
+    } catch (e) {
+      // eslint-disable-next-line @typescript-eslint/no-extra-semi, no-extra-semi
+      ;({ stack } = e as Error)
+    }
+    console.warn(
+      'An input selector returned a different result when passed same arguments.' +
+        '\nThis means your output selector will likely run more frequently than intended.' +
+        '\nAvoid returning a new reference inside your input selector, e.g.' +
+        '\n`createSelector([state => state.todos.map(todo => todo.id)], todoIds => todoIds.length)`',
+      {
+        arguments: inputSelectorArgs,
+        firstInputs: inputSelectorResults,
+        secondInputs: inputSelectorResultsCopy,
+        stack
+      }
+    )
+  }
+}