fix(jest-mock): tweak typings to allow jest.replaceProperty() replace methods (#14008)

mrazauskas · web-flow · commit c40ef2121b31 · 2023-04-09T10:53:41.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,7 @@
 - `[jest-config]` Handle frozen config object ([#14054](https://github.com/facebook/jest/pull/14054))
 - `[jest-environment-jsdom, jest-environment-node]` Fix assignment of `customExportConditions` via `testEnvironmentOptions` when custom env subclass defines a default value ([#13989](https://github.com/facebook/jest/pull/13989))
 - `[jest-matcher-utils]` Fix copying value of inherited getters ([#14007](https://github.com/facebook/jest/pull/14007))
+- `[jest-mock]` Tweak typings to allow `jest.replaceProperty()` replace methods ([#14008](https://github.com/facebook/jest/pull/14008))
 - `[jest-snapshot]` Fix a potential bug when not using prettier and improve performance ([#14036](https://github.com/facebook/jest/pull/14036))
 - `[@jest/transform]` Do not instrument `.json` modules ([#14048](https://github.com/facebook/jest/pull/14048))
 
diff --git a/packages/jest-mock/__typetests__/mock-functions.test.ts b/packages/jest-mock/__typetests__/mock-functions.test.ts
@@ -497,20 +497,25 @@ expectError(
 
 // replaceProperty + Replaced
 
-const obj = {
-  fn: () => {},
-
+const replaceObject = {
+  method: () => {},
   property: 1,
 };
 
-expectType<Replaced<number>>(replaceProperty(obj, 'property', 1));
-expectType<void>(replaceProperty(obj, 'property', 1).replaceValue(1).restore());
+expectType<Replaced<number>>(replaceProperty(replaceObject, 'property', 1));
+expectType<Replaced<() => void>>(
+  replaceProperty(replaceObject, 'method', () => {}),
+);
+expectType<void>(
+  replaceProperty(replaceObject, 'property', 1).replaceValue(1).restore(),
+);
 
-expectError(replaceProperty(obj, 'invalid', 1));
-expectError(replaceProperty(obj, 'property', 'not a number'));
-expectError(replaceProperty(obj, 'fn', () => {}));
+expectError(replaceProperty(replaceObject, 'invalid', 1));
+expectError(replaceProperty(replaceObject, 'property', 'not a number'));
 
-expectError(replaceProperty(obj, 'property', 1).replaceValue('not a number'));
+expectError(
+  replaceProperty(replaceObject, 'property', 1).replaceValue('not a number'),
+);
 
 interface ComplexObject {
   numberOrUndefined: number | undefined;
diff --git a/packages/jest-mock/src/index.ts b/packages/jest-mock/src/index.ts
@@ -177,17 +177,13 @@ export interface Replaced<T = unknown> {
    * Restore property to its original value known at the time of mocking.
    */
   restore(): void;
-
   /**
    * Change the value of the property.
    */
   replaceValue(value: T): this;
 }
 
-type ReplacedPropertyRestorer<
-  T extends object,
-  K extends PropertyLikeKeys<T>,
-> = {
+type ReplacedPropertyRestorer<T extends object, K extends keyof T> = {
   (): void;
   object: T;
   property: K;
@@ -995,10 +991,10 @@ export class ModuleMocker {
   /**
    * Check whether the given property of an object has been already replaced.
    */
-  private _findReplacedProperty<
-    T extends object,
-    K extends PropertyLikeKeys<T>,
-  >(object: T, propertyKey: K): ReplacedPropertyRestorer<T, K> | undefined {
+  private _findReplacedProperty<T extends object, K extends keyof T>(
+    object: T,
+    propertyKey: K,
+  ): ReplacedPropertyRestorer<T, K> | undefined {
     for (const {restore} of this._spyState) {
       if (
         'object' in restore &&
@@ -1328,11 +1324,11 @@ export class ModuleMocker {
     return descriptor[accessType] as Mock;
   }
 
-  replaceProperty<
-    T extends object,
-    K extends PropertyLikeKeys<T>,
-    V extends T[K],
-  >(object: T, propertyKey: K, value: V): Replaced<T[K]> {
+  replaceProperty<T extends object, K extends keyof T>(
+    object: T,
+    propertyKey: K,
+    value: T[K],
+  ): Replaced<T[K]> {
     if (object === undefined || object == null) {
       throw new Error(
         `replaceProperty could not find an object on which to replace ${String(
