[vscode] allow installation of extension packs

[vince-fugnitto]

What it does

Fixes #6611

• added extensionPack property to PluginPackage interface.
• when getting dependencies, ensure that extensionPack dependencies are also loaded. Extensions packs can now be unloaded and their bundled extensions installed.

How to test

1. start the application
   • for test purposes a minimal application was used:
     • no @theia/java, @theia/java-debug, @theia/textmate-grammars
     • added @theia/vscode-builtin-java
2. install the java extension pack: https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-pack
3. should notice the extensions present in the pack unloaded

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• as a reviewer, I agree to behave in accordance with the review guidelines

Signed-off-by: Vincent Fugnitto vincent.fugnitto@ericsson.com

cc @eclipse-theia/plugin-system

[JPinkney]

Tested it with both the java extension pack and the python extension pack and it works well

[vince-fugnitto]

I've verified with the latest changes that:

• extensions which describe extensionPacks successfully work:
  • using python extension pack
  • using java extension pack
• extensions which describe extensionDependencies successfully work:
  • using small markdown julia extension which pulls language-julia

[vince-fugnitto]

@lmcbout did you get a chance to try it out for yourself?

[marcdumais-work]

• no @theia/java, @theia/textmate-grammars

As well one should remove @theia/java-debug, else it pulls @theia/java as dependency

• added @theia/vscode-builtin-java

BTW, testing a bit with @lmcbout , it looks like adding the built-in as a npm dependency is not enough to have it be discovered/used: we had no syntax highlighting until we copied it under <workspace>/plugins/, restarted the BE and reset the FE layout.

About the need to restart the BE / reset the FE, so that plugins work correctly: I think this is probably the problem that @akosyakov was referring-to in a recent dev-meeting?

[vince-fugnitto]

As well one should remove @theia/java-debug, else it pulls @theia/java as dependency

Correct, to be fair I removed whatever was not necessary.
Same thing when testing the python pack, the @theia/python extension was removed.

BTW, testing a bit with @lmcbout , it looks like adding the built-in as a npm dependency is not enough to have it be discovered/used: we had no syntax highlighting until we copied it under <workspace>/plugins/, restarted the BE and reset the FE layout.

The builtins cannot be consumed as npm dependencies, they must be added as plugins.
Is this what you meant?

About the need to restart the BE / reset the FE, so that plugins work correctly: I think this is probably the problem that @akosyakov was referring-to in a recent dev-meeting?

I'm not sure if hot reload works at the moment (the fact that the FE had to be restarted).

[lmcbout]

After testing with @marcdumais-work and having the @theia/vscode-builtin-java running
The pack extension seems to work
tested on Ubuntu 16.04