x/tools/gopls: feature: offer completion for variable name that is incorrectly initialized

gopls version

Build info

golang.org/x/tools/gopls (devel) golang.org/x/tools/gopls@(devel) github.com/BurntSushi/toml@v1.2.1 h1:9F2/+DoOYIOksmaJFPw1tGFy1eDnIJXg+UHjuD8lTak= github.com/google/go-cmp@v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI= golang.org/x/exp/typeparams@v0.0.0-20221212164502-fae10dda9338 h1:2O2DON6y3XMJiQRAS1UWU+54aec2uopH3x7MAiqGW6Y= golang.org/x/mod@v0.21.0 h1:vvrHzRwRfVKSiLrG+d4FMl/Qi4ukBCE6kZlTUkDYRT0= golang.org/x/sync@v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ= golang.org/x/telemetry@v0.0.0-20240927184629-19675431963b h1:PfPrmVDHfPgLVpiYnf2R1uL8SCXBjkqT51+f/fQHR6Q= golang.org/x/text@v0.19.0 h1:kTxAhCbGbxhK0IwgSKiMO5awPoDQ0RpfiVYBfK860YM= golang.org/x/tools@v0.21.1-0.20240508182429-e35e4ccd0d2d => ../ golang.org/x/vuln@v1.0.4 h1:SP0mPeg2PmGCu03V+61EcQiOjmpri2XijexKdzv8Z1I= honnef.co/go/tools@v0.4.7 h1:9MDAWxMoSnB6QoSqiVr7P5mtkT9pOc1kSxchzPCnqJs= mvdan.cc/gofumpt@v0.7.0 h1:bg91ttqXmi9y2xawvkuMXyvAA/1ZGJqYAEGjXuP0JXU= mvdan.cc/xurls/v2@v2.5.0 h1:lyBNOm8Wo71UknhUs4QTFUNNMyxy2JEIaKKo0RWOh+8= go: go1.23.2

go env

GO111MODULE='auto'
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/xzb/Library/Caches/go-build'
GOENV='/Users/xzb/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/xzb/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/Users/xzb/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.23.2'
GODEBUG=''
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/xzb/Library/Application Support/go/telemetry'
GCCGO='gccgo'
GOARM64='v8.0'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD=''
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 -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/gv/r110hgbx1gbgzp95kf_q71x40000gn/T/go-build2905454119=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

func main() {
    foo = 1  // incorrectly initialized
    bar := foo + 1  // no completion candidates item for `foo`
}

What did you see happen?

What did you expect to see?

offer completion for foo in second line bar := foo + 1, offer a quickfix that add the missing : in first line.

Since an unused variable is always a error in go, the first line will have an error within expectation when writing from top to bottom, regardless this is a incorrectly initialized error rather than unused variable, which makes the lack of completion candidates surprising to me, further, the fix is annoy, because go-to-def does not work, I need to manually locate the first line where I miss a :.

If this quickfix exists, one could stop writing : to initialize variables, which requires two keystroke : shift+;, and let code action do the thing where it is later used. Even better, gopls can automatically add the missing : when user confirm the completion item.

Editor and settings

No response

Logs

No response

golang / go