Enable build cache and HMR

[dlabrecq]

Enable build cache and HMR.

https://issues.redhat.com/browse/COST-3220

[Hyperkid123]

@dlabrecq ok I was able to get it working. The issues is with direct default exports. See: https://github.com/pmmmwh/react-refresh-webpack-plugin/blob/main/docs/TROUBLESHOOTING.md#edits-always-lead-to-full-reload

This diff made it work for me:

diff --git a/src/app.tsx b/src/app.tsx
index aa66f29e..61526146 100644
--- a/src/app.tsx
+++ b/src/app.tsx
@@ -13,7 +13,7 @@ export interface AppOwnProps {
   basename: string;
 }
 
-interface AppStateProps {}
+interface AppStateProps { }
 
 interface AppDispatchProps {
   history: any;
@@ -88,4 +88,8 @@ const mapStateToProps = createMapStateToProps<AppOwnProps, AppStateProps>((state
 
 const mapDispatchToProps: AppDispatchProps = { history };
 
-export default compose<React.ComponentType<AppOwnProps>>(withRouter, connect(mapStateToProps, mapDispatchToProps))(App);
+const ComposedApp = compose<React.ComponentType<AppOwnProps>>(
+  withRouter,
+  connect(mapStateToProps, mapDispatchToProps)
+)(App);
+export default ComposedApp;
diff --git a/src/appEntry.tsx b/src/appEntry.tsx
index 76f63d39..bbdeca52 100644
--- a/src/appEntry.tsx
+++ b/src/appEntry.tsx
@@ -29,7 +29,7 @@ const store = configureStore({
   // },
 });
 
-export default () => {
+const AppEntry = () => {
   const basename = getBaseName(window.location.pathname);
   const locale = getLocale();
 
@@ -46,3 +46,5 @@ export default () => {
     </div>
   );
 };
+
+export default AppEntry;

[Hyperkid123]

It is possible that making changes to some nested components that follow the same pattern might cause a full refresh. But making sure the function is not directly exported as a default module will fix the potential issue.

[codecov-commenter]

Codecov Report

Merging #2656 (b75de5c) into main (413e764) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##             main    #2656    +/-   ##
========================================
  Coverage   65.70%   65.70%            
========================================
  Files         451      451            
  Lines        8918     8918            
  Branches     2081     1937   -144     
========================================
  Hits         5860     5860            
  Misses       3055     3055            
  Partials        3        3            

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[dlabrecq]

Thank you for the help, Martin.

I wasn't able to see HMR working with the diffs, so I temporarily disabled the feature. Just going to use the build cache for now.

I created an issue to refactor our unnamed default exports in order to enable HMR separately.
https://issues.redhat.com/browse/COST-3224