Code intelligence 3.4 tracking issue

[chrismwendt]

User story

• As a user, code intel sometimes feels slow and buggy and I want it to feel fast and smooth. Hover tooltips don't show up and I can't click "Find references" consistently.

• As a user, I want the option to stay in my code host when clicking "Go to definition" or "Find references".

Issues

• Add "Submit code intel feedback" button to the toolbar
  • Go Add button to submit feedback sourcegraph-go#70
  • TypeScript Add button to submit feedback sourcegraph-typescript#175
  • Basic code intel Add button to submit feedback code-intel-extensions#100
• Upload basic-code-intel coverage Upload coverage data code-intel-extensions#113
• Use @sourcegraph/lsp-client Use @sourcegraph/lsp-client sourcegraph-go#28
  • Use @sourcegraph/lsp-client in the Go extension Use lsp-client sourcegraph-go#36
  • Add support for custom initializationOptions in lsp-client feat: support custom initializationOptions lsp-client#36
  • Move originalRootUri to initializationOptions LSP-conformant originalRootURI go-langserver#369 subsumed by the next item
  • Support "rootUri": "git://..." in go-langserver Support git:// in the rootUri go-langserver#373
  • Derive zipURL from zipURLTemplate Derive zip URL from template go-langserver#370
• Single-click j2d https://github.com/sourcegraph/enterprise/issues/11047
  • Expose API in codeintellify Expose the currently hovered token and support disabling pinning codeintellify#106
  • Use in web app https://github.com/sourcegraph/sourcegraph/pull/3444
  • Split it into 2 pieces:
    • Replace click-based pinning with pin icon
    • Use single-click for j2d
  • Gather evidence from users or the team that this is better
• Investigate LSIF (discussion and doc at https://sourcegraph.slack.com/archives/CHXHX7XAS/p1556571369004700)
• Make identCharPattern configurable per language https://github.com/sourcegraph/sourcegraph/issues/3614
• Add a delay to the disappearance of the hover tooltip Delay hiding the tooltip when mouse is moved away codeintellify#48
• Show loading indicator somewhere other than the tooltip
• Highlight other occurrences of variables https://github.com/sourcegraph/sourcegraph/issues/1283
• Dependency graph (insofar as it makes basic code intel more precise)
• References panel in code hosts
• Radical thought: pre-compute hovers in the background (like Kythe, Haskell Code Explorer)
• Support j2d on parameters and local variables (using tree-sitter)
  • Proof of concept tree-sitter proof of concept code-intel-extensions#110
• Filter definitions for all languages Add support for filtering definitions by import path code-intel-extensions#67
• Filter definitions by parent (from ctags)

[chrismwendt]

@sqs I ordered the list of tasks based on our code intel sync today. Does this reflect your expectation of the order of priorities, too?

[felixfbecker]

lsp-client has been pushed through 2 iterations now, so I would like to see it prioritised higher. There are now two features added since the creation of lsp-client that should be shared across all languages (code intel toggle and connection troubleshooting notifications), but keep getting implemented per-language, causing inconsistent feature support and more work for us.

This issue claims that depends on changes/a specific PR in lsp-client, but the PR description says "this is a total hack" and I don't know why it is needed and can't be expressed through standard LSP (at least there is no explanation in sourcegraph/sourcegraph-go#28)

[felixfbecker]

I would also like to point out that our codeintel extensions (both basic code intel and precise) still have 0% test coverage.

[chrismwendt]

The time is indeed ripe for switching to lsp-client! Yet another item to add to the growing list is the LSIF prototype

Since switching to lsp-client is an extension-level change, every customer will get the improvements without upgrading their deployments ✨

Now, for largely historical reasons, go-langserver is not quite 100% LSP-compliant.

Given this, how do we integrate lsp-client?

Could we patch go-langserver and use lsp-client immediately? This would break code intel for customers with existing go-langserver deployments. Could we support both simultaneously? How would the extension know which version of go-langserver it's communicating with?

We could patch go-langserver immediately and push lsp-client through 2 more iterations to fulfill our 2 minor version support policy, but how can we get it integrated sooner?

[chrismwendt]

Next iteration's tracking issue: https://github.com/sourcegraph/sourcegraph/issues/4066