Index: node_modules/reselect/src/devModeChecks/identityFunctionCheck.ts
===================================================================
--- node_modules/reselect/src/devModeChecks/identityFunctionCheck.ts	(revision a762898ecd37a452c782821d4c2c4955c6ed2521)
+++ node_modules/reselect/src/devModeChecks/identityFunctionCheck.ts	(revision a762898ecd37a452c782821d4c2c4955c6ed2521)
@@ -0,0 +1,53 @@
+import type { AnyFunction } from '../types'
+
+/**
+ * Runs a check to determine if the given result function behaves as an
+ * identity function. An identity function is one that returns its
+ * input unchanged, for example, `x => x`. This check helps ensure
+ * efficient memoization and prevent unnecessary re-renders by encouraging
+ * proper use of transformation logic in result functions and
+ * extraction logic in input selectors.
+ *
+ * @param resultFunc - The result function to be checked.
+ * @param inputSelectorsResults - The results of the input selectors.
+ * @param outputSelectorResult - The result of the output selector.
+ *
+ * @see {@link https://reselect.js.org/api/development-only-stability-checks#identityfunctioncheck `identityFunctionCheck`}
+ *
+ * @since 5.0.0
+ * @internal
+ */
+export const runIdentityFunctionCheck = (
+  resultFunc: AnyFunction,
+  inputSelectorsResults: unknown[],
+  outputSelectorResult: unknown
+) => {
+  if (
+    inputSelectorsResults.length === 1 &&
+    inputSelectorsResults[0] === outputSelectorResult
+  ) {
+    let isInputSameAsOutput = false
+    try {
+      const emptyObject = {}
+      if (resultFunc(emptyObject) === emptyObject) isInputSameAsOutput = true
+    } catch {
+      // Do nothing
+    }
+    if (isInputSameAsOutput) {
+      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(
+        'The result function returned its own inputs without modification. e.g' +
+          '\n`createSelector([state => state.todos], todos => todos)`' +
+          '\nThis could lead to inefficient memoization and unnecessary re-renders.' +
+          '\nEnsure transformation logic is in the result function, and extraction logic is in the input selectors.',
+        { stack }
+      )
+    }
+  }
+}