redux modules sometimes do not hot reload

[bdefore]

redux modules sometimes do not hot reload

[bdefore]

@gaearon perhaps you can see what i'm doing wrong here?

[gaearon]

Just to clarify.. Webpack analyzes module.hot.accept() calls at compile time. Both require() and module.hot.accept() need to have paths hard-coded there for hot reloading to work (as far as I know). I don't think it works with dynamic paths, no matter what you use to calculate them. Did it work before with dynamic paths for you?

[bdefore]

@gaearon i don't think it ever worked with dynamic paths, no. the original didn't need to because all of its reducers lived in a ./modules/index path relative to where the store was created. my situation is somewhat different because i'm configuring webpack to build a bundle from the project root (via contextRoot and some webpack aliases) that includes this library as a dependency and has access to both ./src as well as ./node_modules/universal-redux/src

I've noticed that if I put the following in my setup:

    module.hot.accept('redux/modules/index', function () {
      console.log('replacing reducer in project...');
      store.replaceReducer(require('redux/modules/index'));
    });

    module.hot.accept('./modules/index', function () {
      console.log('replacing reducer in universal-redux...');
      store.replaceReducer(require('./modules/index'));
    });

It will hot reload the modules/test reducer relative to universal-redux, but not the redux/modules/index reducer relative to the project root. The console output after changing both files is:

[HMR] connected
[HMR] bundle rebuilding
[HMR] bundle rebuilt in 458ms
[HMR] Checking for updates on the server...
replacing reducer in universal-redux...
[HMR] Updated modules:
[HMR]  - ./~/universal-redux/lib/redux/modules/index.js
[HMR] App is up to date.
[HMR] bundle rebuilding
[HMR] bundle rebuilt in 498ms
[HMR] Checking for updates on the server...
[HMR] The following modules couldn't be hot updated: (Full reload needed)
[HMR]  - ./src/redux/modules/index.js

It's as if the accept route is not being mapped correctly.

[bdefore]

This issue still remains, but I've noticed that it occurs in react-redux-universal-hot-example too, in the same circumstances. I'm not sure I fully understand when a change to a reducer module is 'reloadable', and need to put together some steps that are reproducible. For example, either in universal-redux or in react-redux-universal-hot-example, adding a new property to the initialState appears to fail hot reloading with reducers that have already been initialized.

[gaearon]

Please file an issue with DevTools with instructions to reproduce.

[bdefore]

The commit that fixed this is here: 436d748

What is not clear to me is why the import of reducers from a webpack alias, even if not used, would itself break hot reloading. All the way from initial client entry to the point where module.hot.accept is assigned, modules are required to be loaded via relative paths, or else modules fail to hot reload.