docs: run tests in repl (#14206)

doc/TESTING.md

@@ -15,5 +15,26 @@ To watch the tests:
    make test-watch
 ```
   
+To run test in REPL
+
+```
+   make test
+   yarn shadow-cljs cljs-repl test # or start the REPL in your editor 
+``` 
+
+Then start the test process with
+
+```
+   node --require ./test-resources/override.js target/test/test.js --repl
+```
+
+You can run single test in REPL like this
+
+```clojure
+(require 'cljs.test)
+(cljs.test/test-var #'status-im.data-store.chats-test/normalize-chat-test)
+```
+
+
 
 Tests will use the bindings in `modules/react-native-status/nodejs`, if you make any changes to these you will need to restart the watcher.