fix(pretty-format): correctly detect memo

CHANGELOG.md

@@ -53,8 +53,9 @@
 - `[jest-snapshot]` [**BREAKING**] Distinguish empty string from internal snapshot not written ([#8898](https://github.com/facebook/jest/pull/8898))
 - `[jest-snapshot]` [**BREAKING**] Remove `report` method and throw matcher errors ([#9049](https://github.com/facebook/jest/pull/9049))
 - `[jest-transform]` Properly cache transformed files across tests ([#8890](https://github.com/facebook/jest/pull/8890))
-- `[jest-utils]` Allow querying process.domain ([#9136](https://github.com/facebook/jest/pull/9136))
 - `[jest-transform]` Don't fail the test suite when a generated source map is invalid ([#9058](https://github.com/facebook/jest/pull/9058))
+- `[jest-utils]` Allow querying process.domain ([#9136](https://github.com/facebook/jest/pull/9136))
+- `[pretty-format]` Correctly detect memoized elements ([#9196](https://github.com/facebook/jest/pull/9196))
 
 ### Chore & Maintenance
 

packages/jest-fake-timers/package.json

@@ -17,7 +17,7 @@
     "lolex": "^5.0.0"
   },
   "devDependencies": {
-    "@types/lolex": "^3.1.1"
+    "@types/lolex": "^5.1.0"
   },
   "engines": {
     "node": ">= 8"

packages/pretty-format/package.json

@@ -16,7 +16,7 @@
     "@jest/types": "^24.9.0",
     "ansi-regex": "^5.0.0",
     "ansi-styles": "^4.0.0",
-    "react-is": "^16.8.4"
+    "react-is": "^16.12.0"
   },
   "devDependencies": {
     "@types/react": "*",

packages/pretty-format/src/plugins/ReactElement.ts

@@ -60,7 +60,7 @@ const getType = (element: any) => {
         : 'ForwardRef';
     }
 
-    if (ReactIs.isMemo(type)) {
+    if (ReactIs.isMemo(element)) {
       const functionName =
         type.displayName || type.type.displayName || type.type.name || '';