Syntax highlighting and Intellisense broken in VS Code 1.86+ when a string with "]" is cast to []byte

[anirudhgiri]

What version of Go, VS Code & VS Code Go extension are you using?

Version Information

• Run go version to get version of Go from the VS Code integrated terminal.

  • go version go1.21.6 linux/amd64

• Run gopls -v version to get version of Gopls from the VS Code integrated terminal.

  • golang.org/x/tools/gopls v0.14.2

• Run code -v or code-insiders -v to get version of VS Code or VS Code Insiders.

  • 1.86.0

• Check your installed extensions to get the version of the VS Code Go extension

  • v0.40.3

• Run Ctrl+Shift+P (Cmd+Shift+P on Mac OS) > Go: Locate Configured Go Tools command.

  • Checking configured tools....
    GOBIN: undefined
    toolsGopath:
    gopath: /home/anirudh-g/go
    GOROOT: /snap/go/10489
    PATH: /snap/go/10489/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/snap/bin

  go: /snap/go/current/bin/go: go version go1.21.6 linux/amd64

  gopls: /home/anirudh-g/go/bin/gopls (version: v0.14.2 built with go: go1.21.4)
  gotests: not installed
  gomodifytags: not installed
  impl: not installed
  goplay: not installed
  dlv: /home/anirudh-g/go/bin/dlv (version: v1.21.0 built with go: go1.21.0)
  staticcheck: /home/anirudh-g/go/bin/staticcheck (version: v0.4.5 built with go: go1.21.0)

go env
Workspace Folder (playground): /home/anirudh-g/Documents/programming/golang/playground
GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/anirudh-g/.cache/go-build'
GOENV='/home/anirudh-g/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/anirudh-g/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/anirudh-g/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/snap/go/10489'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/snap/go/10489/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.6'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/home/anirudh-g/Documents/programming/golang/playground/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2453955022=/tmp/go-build -gno-record-gcc-switches'

Share the Go related settings you have added/edited

"go.toolsManagement.autoUpdate": true,
  "go.alternateTools": {
    "go": "/snap/go/current/bin/go"
},

Describe the bug

If a string that contains the ] character is converted to a []byte, both syntax highlighting and intellisense stop working from that line onwards. All subsequent lines of code have incorrect syntax highlighting, and intellisense does not work on those lines of code. This only happens on VSCode version 1.86.0

Steps to reproduce the behavior:

1. Take a project with multiple lines of correctly syntax highlighted code
2. Add the line var myByteArray []byte = []byte("]") somewhere in the middle
3. From that line onward, syntax highlighting and Intellisense ceases to work

Screenshots or recordings

Syntax highlighting on VSCode version 1.86.0:

Expected Syntax highlighting:

[findleyr]

I am not naively able to reproduce this. It would be very suprising if this code broke gopls' intellisense, since gopls is built on top of compiler tools which definitely handle these inputs.

Do you have any other extensions installed that may interact with Go code?

[hyangah]

@anirudhgiri Can you please try semantic token based syntax highlighting and if it works better for you?

"gopls": { "ui.semanticTokens": true }

[anirudhgiri]

Apologies for the late response.

@findleyr I just reproduced it on a different machine running VSCode 1.86.1 with no other extensions installed except vscode-go (please refer to the screenshot below, note that line 6 is highlighted properly while line 8 is not). Are you sure you're using a version of VSCode that is 1.86.0 or above?

@hyangah Yes, adding the provided field to my settings.json seems to fix the issue

[findleyr]

@anirudhgiri indeed, I just installed VS Code 1.86.1 and reproduced, without even installing the Go extension.

This is a VS Code bug. I've filed it as microsoft/vscode#205306. VS Code 1.86 switched to a new Go syntax engine, apparently.

[findleyr]

I'm going to leave this open for visibility. For now, the workaround is to use "gopls": { "ui.semanticTokens": true }.

[drgrib]

I will add my very similar case to this issue and note that adding this to my user settings or project settings.json does not fix the issue:

	"gopls": {
		"ui.semanticTokens": true
	},

Steps to Reproduce

Add this line before any Go code:

var baseNameRE = regexp.MustCompile(`(\d+)(.*)`)