Merge #3534

3534: Feature: vscode impl nightlies download and installation r=Veetaha a=Veetaha

I need to test things more, but the core shape of the code is quite well-formed.
The main problem is that we save the release date only for nightlies and there are no means to get the release date of the stable extension (i.e. for this we would need to consult the github releases via a network request, or we would need to somehow save this info into package.json or any other file accessible from the extension code during the deployment step, but this will be very hard I guess).
So there is an invariant that the users can install nightly only from our extension and they can't do it manually, because when installing the nightly `.vsix` we actually save its release date to `globalState`

Closes: #3402

TODO:
- [x] More manual tests and documentation

cc @matklad @lnicola 

Co-authored-by: Veetaha <[email protected]>
Co-authored-by: Veetaha <[email protected]>

1 files changed, 19 insertions, 0 deletions

diff --git a/docs/user/readme.adoc b/docs/user/readme.adoc
index 4e99dd0a6..2e6c6112f 100644
--- a/docs/user/readme.adoc
+++ b/docs/user/readme.adoc
@@ -65,6 +65,25 @@ Note that we only support the latest version of VS Code.
 
 The extension will be updated automatically as new versions become available. It will ask your permission to download the matching language server version binary if needed.
 
+===== Nightly
+
+We ship nightly releases for VS Code. To help us out with testing the newest code and follow the bleeding edge of our `master`, please use the following config:
+
+[source,json]
+----
+{ "rust-analyzer.updates.channel": "nightly" }
+----
+
+You will be prompted to install the `nightly` extension version. Just click `Download now` and from that moment you will get automatic updates each 24 hours.
+
+If you don't want to be asked for `Download now` every day when the new nightly version is released add the following to your `settings.json`:
+[source,json]
+----
+{ "rust-analyzer.updates.askBeforeDownload": false }
+----
+
+NOTE: Nightly extension should **only** be installed via the `Download now` action from VS Code.
+
 ==== Building From Source
 
 Alternatively, both the server and the plugin can be installed from source: