gopls/internal/server: fix two bugs related to dynamic configuration

Fix two bugs related to dynamic configuration, that combine to prevent
several clients from correctly configuring gopls, as reported in
golang/go#65519 (Eglot), slack (lsp-mode), and team chat (Helix).

The first bug has existed ~forever: when we make a
workspace/configuration request in response to a didChangeConfiguration
notification, we attempt to fetch the "global" settings by passing
"scopeURI": "". The LSP spec defines "scopeURI" as a nullable URI:

https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#configurationItem

Apparently, Javascript-based clients such as VS Code and coc.nvim (the
two clients I regularly test with) will happily accept "" as a falsy
value, and so this global query works. However, this query fails in
Eglot (and likely other clients), causing didChangeConfiguration not to
work.

The second bug is new: When adding a new workspace folder we were
failing to overwrite opts with the correct value (:= vs =, alas). This
initial query had been masking the bug described above in Emacs, whereas
in VS Code the (incorrectly) successful workspace/configuration request
above masked the new bug. Since they both fail in Eglot, they are
revealed.

The fake editor is updated to reject the "" scope, highlighting the
first bug. A new integration test is added to exercise the second bug,
by way of a new integration test option to add per-folder configuration.

Additionally, a marker test is added to exercise static configuration,
which is when the client does not support the configuration capability
at all. This wasn't actually broken, as first suspected, but the test is
useful to include anyway, as we had no tests for this client behavior.

Fixes golang/go#65519

Change-Id: Ie7170e3a26001546d4e334b83e6e73cd4ade10d8
Reviewed-on: https://go-review.googlesource.com/c/tools/+/563475
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Findley <rfindley@google.com>
6 files changed
tree: a6f787fa676f59464e236cb1f361abd69d421031
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. copyright/
  6. cover/
  7. go/
  8. godoc/
  9. gopls/
  10. imports/
  11. internal/
  12. playground/
  13. present/
  14. refactor/
  15. txtar/
  16. .gitattributes
  17. .gitignore
  18. .prettierrc
  19. codereview.cfg
  20. CONTRIBUTING.md
  21. go.mod
  22. go.sum
  23. LICENSE
  24. PATENTS
  25. README.md
README.md

Go Tools

PkgGoDev

This repository provides the golang.org/x/tools module, comprising various tools and packages mostly for static analysis of Go programs, some of which are listed below. Use the “Go reference” link above for more information about any package.

It also contains the golang.org/x/tools/gopls module, whose root package is a language-server protocol (LSP) server for Go. An LSP server analyses the source code of a project and responds to requests from a wide range of editors such as VSCode and Vim, allowing them to support IDE-like functionality.

Selected commands:

  • cmd/goimports formats a Go program like go fmt and additionally inserts import statements for any packages required by the file after it is edited.
  • cmd/callgraph prints the call graph of a Go program.
  • cmd/digraph is a utility for manipulating directed graphs in textual notation.
  • cmd/stringer generates declarations (including a String method) for “enum” types.
  • cmd/toolstash is a utility to simplify working with multiple versions of the Go toolchain.

These commands may be fetched with a command such as

go install golang.org/x/tools/cmd/goimports@latest

Selected packages:

  • go/ssa provides a static single-assignment form (SSA) intermediate representation (IR) for Go programs, similar to a typical compiler, for use by analysis tools.

  • go/packages provides a simple interface for loading, parsing, and type checking a complete Go program from source code.

  • go/analysis provides a framework for modular static analysis of Go programs.

  • go/callgraph provides call graphs of Go programs using a variety of algorithms with different trade-offs.

  • go/ast/inspector provides an optimized means of traversing a Go parse tree for use in analysis tools.

  • go/cfg provides a simple control-flow graph (CFG) for a Go function.

  • go/expect reads Go source files used as test inputs and interprets special comments within them as queries or assertions for testing.

  • go/gcexportdata and go/gccgoexportdata read and write the binary files containing type information used by the standard and gccgo compilers.

  • go/types/objectpath provides a stable naming scheme for named entities (“objects”) in the go/types API.

Numerous other packages provide more esoteric functionality.

Contributing

This repository uses Gerrit for code changes. To learn how to submit changes, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.

JavaScript and CSS Formatting

This repository uses prettier to format JS and CSS files.

The version of prettier used is 1.18.2.

It is encouraged that all JS and CSS code be run through this before submitting a change. However, it is not a strict requirement enforced by CI.