lit-element

The semantic dom diff plugin uses some global variables like __mocha_context__ and __snapshot__ which are only available in a karma mocha context. When it's user in other test runners, or karma without mocha, it crashes with an unhelpful message.

We should check for these variables, and throw a helpful error to the user that explains this plugin can only be used in Karma.

Describe the bug
Title

To Reproduce
Steps to reproduce the behavior:

1. clone template
2. open vs code
3. go to app-home.ts
4. notice red lines

Expected behavior
The fast components should be recognized.

Screenshots

**Desktop (please complete the fol

The generator currently outputs TypeScript projects only. It should have an option to output JavaScript projects.

This could be accomplished without duplicating code by the following steps

1. If the TypeScript option is selected, continue as normal
2. If the JavaScript option is selected, run all the same steps as the TypeScript generator, but add the following steps afterwards:
   1. Run

I catch a Exception, When I download Vaadin 16 Business Starter and copy /target/index.ts(html) to fronted dir. Then run command :

mvn jetty:run-exploded -Dvaadin.productionMode

Open browser: 127.0.0.1:8080

HTTP ERROR 500
Problem accessing /. Reason:

    Server Error

The IDEA shows Error is

java.io.IOException: Failed to load content of 
'D:\broderick\d

As svg icons are supported in all modern browsers right now, maybe we can update it.

Some references:

• https://medium.com/swlh/are-you-using-svg-favicons-yet-a-guide-for-modern-browsers-836a6aace3df
• https://evilmartians.com/chronicles/how-to-favicon-in-2021-six-files-that-fit-most-needs
• https://catalin.red/svg-favicon-light-dark-theme/