Goto Implementation - Unable to open URI

[ninth-dev]

When using Goto Implementation on a dependency, we will get a Unable to Open URI error.

1. Current viewing the source of "Monad.scala" from the cats package.

2. Using LSP: Goto Implementation
   • Here we can see a list of implementation. However the URI is "jar:file:///....."

3. Selecting any results in an error with "Unable to open URI"

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Trying the same thing in with vscode works as intended.

Some notes on how it works in vscode.

• vscode uses virtual documents.
• it registers the text document content provider for jar in this file.
• it uses the same provider for decodeFile load the content.

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Possible solution

1. in metals.py override on_open_uri_async.

Called when a language server reports to open an URI. If you know how to handle this URI, then return True and invoke the passed-in callback some time.

2. Here we can check if the URI starts with "jar:"

3. invoke the LspMetalsFileDecoderCommand instead of the callback.

   • we will need to make some changes here to allow "jar"

The above would work. However when viewing the opened file - LSP will no longer be enabled. ( maybe because the file is open as a scratch file? )

To ensure LSP is still enabled when viewing these files, we can simulate what Goto Defintion does.

• create a file under .metals/readonly/dependencies/.....

I've got a rough implementation working. See PR #119

[rchl]

The above would work. However when viewing the opened file - LSP will no longer be enabled. ( maybe because the file is open as a scratch file? )

To ensure LSP is still enabled when viewing these files, we can simulate what Goto Defintion does.

This is how you enable LSP for your custom URI: https://github.com/sublimelsp/LSP-jdtls/blob/e723885514c765cf67d94fff21eba269f782977b/LSP-jdtls.sublime-settings#L5-L10

[ayoub-benali]

Fixed by https://github.com/scalameta/metals-sublime/pull/120