x/tools/gopls: prefill new go files with package statement

[danvolchek]

gopls version

Version info

Build info
----------
golang.org/x/tools/gopls v0.18.1
    golang.org/x/tools/gopls@v0.18.1 h1:2xJBNzdImS5u/kV/ZzqDLSvlBSeZX+pWY9uKVP7Pask=
    github.com/BurntSushi/toml@v1.4.1-0.20240526193622-a339e1f7089c h1:pxW6RcqyfI9/kWtOwnv/G+AzdKuy2ZrqINhenH4HyNs=
    github.com/google/go-cmp@v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
    golang.org/x/exp/typeparams@v0.0.0-20241210194714-1829a127f884 h1:1xaZTydL5Gsg78QharTwKfA9FY9CZ1VQj6D/AZEvHR0=
    golang.org/x/mod@v0.23.0 h1:Zb7khfcRGKk+kqfxFaP5tZqCnDZMjC5VtUBs87Hr6QM=
    golang.org/x/sync@v0.11.0 h1:GGz8+XQP4FvTTrjZPzNKTMFtSXH80RAzG+5ghFPgK9w=
    golang.org/x/telemetry@v0.0.0-20241220003058-cc96b6e0d3d9 h1:L2k9GUV2TpQKVRGMjN94qfUMgUwOFimSQ6gipyJIjKw=
    golang.org/x/text@v0.22.0 h1:bofq7m3/HAFvbF51jz3Q9wLg3jkvSPuiZu/pD1XwgtM=
    golang.org/x/tools@v0.30.1-0.20250221230316-5055f70f240c h1:Ja/5gV5a9Vvho3p2NC/T2TtxhHjrWS/2DvCKMvA0a+Y=
    golang.org/x/vuln@v1.1.3 h1:NPGnvPOTgnjBc9HTaUx+nj+EaUYxl5SJOWqaDYGaFYw=
    honnef.co/go/tools@v0.5.1 h1:4bH5o3b5ZULQ4UrBmP+63W9r7qIkqJClEA9ko5YKx+I=
    mvdan.cc/gofumpt@v0.7.0 h1:bg91ttqXmi9y2xawvkuMXyvAA/1ZGJqYAEGjXuP0JXU=
    mvdan.cc/xurls/v2@v2.5.0 h1:lyBNOm8Wo71UknhUs4QTFUNNMyxy2JEIaKKo0RWOh+8=
go: go1.24.0

go env

Env info

AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE=''
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/dan/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/dan/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2088853875=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/home/dan/Desktop/Stuff/development/go-rw2/go.mod'
GOMODCACHE='/home/dan/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/dan/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/lib/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/dan/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/lib/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.1'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

Create a new go file in vscode through the new file right click menu option in the explorer pane.

What did you see happen?

A new, empty go file was created.

What did you expect to see?

This is a feature request - it would be nice if the file was pre-filled with a package statement to avoid the repetitive typing. As is, the new empty file is invalid and causes an expected ';', found 'EOF' problem.

The package name could probably be the directory name if it is the first go file in the directory, otherwise the existing package name for non-test files in that directory. If the file ends in _test.go, the package could also suffixed with _test. I assume something like that will be what users want most often, but in any case they can edit it from there, and I assume any statement will be better than an empty/invalid file.

Editor and settings

    "gopls": {
        "ui.diagnostic.staticcheck": true
    },
    "[go]": {
        "editor.formatOnSave": true
    },
    "go.toolsManagement.autoUpdate": true,

Logs

No response

[mateusz834]

(For the Go repo is should add a copyright header too) 😄.

[gabyhelp]

Related Issues

• x/tools/gopls: Doesn't auto-complete package statements for new files #40713 (closed)
• gopls: Unable to build on vscode #35531 (closed)
• x/tools/gopls: snippets do not replace triggering preamble #59508 (closed)
• x/tools/gopls: organize imports formats the package statement #63153
• x/tools/gopls: invalid errors when using "pkgm" VS Code snippet #39296 (closed)
• x/tools/gopls: run completion using partial type checking of current package #68063
• x/tools/gopls: not working #37119 (closed)
• x/tools/gopls: textEdit calculation wrong. #57384 (closed)
• x/tools/gopls: IDE shows undeclared name on every symbols when accessing from other files #34951 (closed)
• x/tools/gopls: missing semantic tokens for function parameters in block #56257 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[findleyr]

This should be possible (and likely straightforward) with support for willCreateFiles.

This may be a good starter project for someone on the team. Moving to the backlog.

[xieyuschen]

HI @findleyr I'm interested in this feature, and want to have a try. By the way, willCreateFiles doesn't fit this case as:

Hence the WorkspaceEdit can not manipulate the content of the files to be created.

Instead, thedidCreateFiles fits this case, and gopls should use gopls/internal/protocol/command.Dispatch to send a applyEdit rather than modifying files though os.WriteFile.

Besides, I plan to reuse the first suggestion from completion.PackageClauseCompletions as we already analyze the names with different scores.

It would be great if you could provide some guidance or suggestions regarding this. Thank you!

[findleyr]

Hi @xieyuschen, yes please feel free to implement this (I will mark as help-wanted).

By the way, willCreateFiles doesn't fit this case

Ah, thanks for investigating. Handling didCreateFiles sounds good.

[gopherbot]

Change https://go.dev/cl/659595 mentions this issue: gopls: insert package clause when create a new go file