status-react/TROUBLESHOOTING.md

# [DEPRECATED] Undefined is not an object evaluating `register_handler_fx`

## Deprecation note

This type of error should not occur anymore now that we require the namespace in the `fx.cljs` file. 

It can however happen with other macros requiring a cljs namespace. 

The general fix for that type of issue is to have two files for the namespace where your macros are defined, let's say for `my-project.my-macro` namespace you would have: 
- my_macro.cljs in which you need `(:require-macros my-project.my-macro)` and `(:require my-project.the-namespace-used-in-the-macro)`
- my_macro.clj in which you define the macro

That way you don't need to use any magical call like `find-ns` or inline `require` with some kind of call only once switch (which was the root cause of another bug in ``defstyle`` macro because the compilation phase at which the evaluation of the switch is done was not properly considered).

You also want to make sure users are using the macro by using a aliased namespace defined in require statement rather than require-macro and refer to the macro directly. Otherwise it won't require the cljs file and the require statement of the namespace in the macroexpension might not be there.

## Stacktrace

```
13:25:22, Requiring: hi-base32
13:25:23, Possible Unhandled Promise Rejection (id: 0):
TypeError: undefined is not an object (evaluating 'status_im.utils.handlers.register_handler_fx')
eval code
eval@[native code]
asyncImportScripts$@http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:200728:21
tryCatch@http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:26567:23
invoke@http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:26742:32
tryCatch@http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:26567:23
invoke@http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:26643:30
http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:26653:21
tryCallOne@http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:3725:16
http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:3826:27
_callTimer@http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false:28405:17
_callImmediatesPass@http://localhost:8081/index.bundle?pla<…>
```

## Cause

- stacktrace mentions `register_handler_fx`, 
- common cause is when requires have been cleaned up and a require of `status-im.utils.handlers` namespace was removed because it looked like it was unused but was actually used through a fx/defn macro

## Solution

go through known faulty commit looking for deleted requires