Flow: Cannot disable ES5 transpilations

[anasmi]

Moved from here: https://github.com/vaadin/framework/issues/11504

• Vaadin Framework version: 13.0.1
• Browser version: Google Chrome Version 72.0.3626.121 (Official Build) (64-bit)

If I disable the ES5 transpile in the maven build, with true, I still get the following exception, even with latest Chrome and also Safari:

java.lang.IllegalArgumentException: Failed to find the bundle manifest file 'frontend://vaadin-flow-bundle-manifest.json' in the servlet context for 'ES5' browsers. If you are running a dev-mode servlet container in maven e.g. jetty:run change it to jetty:run-exploded. If you are not compiling frontend resources, include the 'vaadin-maven-plugin' in your build script. Otherwise, you can skip this error either by disabling production mode, or by setting the servlet parameter 'original.frontend.resources=true'.
Vaadin plugin is obsviouly enabled, just skipping ES5, but this error happens anyway. ES5 support is pretty useless for me, so I would like to avoid having to compile it.

Can you fix this bug, please?

[gsedlacz]

The issue is remains present in 14.0.0.beta3.
As this is an officially documented feature a bugfix would be nice.

Thank you.

[Artur-]

Workaround:

echo "{}" > src/main/webapp/frontend-es5/vaadin-flow-bundle-manifest.json

[Artur-]

With npm and latest 14 SNAPSHOT, you can do

module.exports.plugins[0].targets.pop()

in webpack.config.js to remove the es5 permutation

[jm-ferreira]

Starting from Vaadin 14.2 ES5 transpilation is disabled by default while running in DevMode.

[jcgueriaud1]

Is it fixed?
Apparently there is a configuration devmode.transpile but it's not documented here:
https://vaadin.com/docs/v14/flow/advanced/tutorial-all-vaadin-properties.html

I've opened a ticket: https://github.com/vaadin/flow-and-components-documentation/issues/1289