"Go: Extract to function" command fails as vscode can't resolve dependencies when using gopls and modules

[luca-battistelli]

Please direct general questions to:

• #vscode channel in Gophers Slack

Please review the documentation before filing an issue.
Helpful pages include:

• GOPATH
• Module Support
• Debugging
  • Set "trace": "log" and share the resulting logs in the debug console when logging an issue.

Please answer these questions before submitting your issue. Thanks!

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

• Run go version to get version of Go
  • go version go1.15.2 darwin/amd64
• Run code -v or code-insiders -v to get version of VS Code or VS Code Insiders
  • 1.49.1
  • 58bb7b2331731bf72587010e943852e13e6fd3cf
  • x64
• Check your installed extensions to get the version of the VS Code Go extension
  • v0.17.0
• Run go env to get the go development environment details

GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/lucabattistelli/Library/Caches/go-build"
GOENV="/Users/lucabattistelli/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/lucabattistelli/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/lucabattistelli/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/lucabattistelli/repos/signalfx-mimi/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/w2/bhwq2wyx2r98trb8_htdvhw00000gq/T/go-build749457552=/tmp/go-build -gno-record-gcc-switches -fno-common"

Share the Go related settings you have added/edited

    "go.useLanguageServer": true,
    "[go]": {
        "editor.formatOnSave": true,
        "editor.codeActionsOnSave": {
            "source.organizeImports": true,
        },
        // Optional: Disable snippets, as they conflict with completion ranking.
        "editor.snippetSuggestions": "none",
    },
    "[go.mod]": {
        "editor.formatOnSave": true,
        "editor.codeActionsOnSave": {
            "source.organizeImports": true,
        },
    },
    "gopls": {
         // Add parameter placeholders when completing a function.
        "usePlaceholders": true,
    
        // If true, enable additional analyses with staticcheck.
        // Warning: This will significantly increase memory usage.
        "staticcheck": false,
    }

Describe the bug

VsCode is looking for dependencies in e.g /usr/local/go/src/rsc.io/quote (from $GOROOT) and /Users/lucabattistelli/go/src/rsc.io/quote (from $GOPATH)

and not in the module cache, where they are instead located, e.g /Users/lucabattistelli/go/pkg/mod/rsc.io/quote\@v1.5.2/

Steps to reproduce the behavior:

1. Download project go-test-modules-gopls-deps.zip (created by following the go modules blog up to "Adding a dependency" and then adding the line a := 2 + 3)
2. Select a := 2 + 3
3. Run the Go: Extract to function command
4. Notice the error

Defaulting to file scope /Users/lucabattistelli/repos/go-test-modules-gopls-deps/hello.go for refactoring (provide an explicit scope to change this) hello.go:6:2: Error: could not import rsc.io/quote (cannot find package "rsc.io/quote" in any of: /usr/local/go/src/rsc.io/quote (from $GOROOT) /Users/lucabattistelli/go/src/rsc.io/quote (from $GOPATH))

Screenshots or recordings

If applicable, add screenshots or recordings to help explain your problem.

[hyangah]

@luca-battistelli thanks for filing an issue. The tool implementing "Go: Extract to function" doesn't seem to handle modules mode. If you are already using gopls, gopls offers the 'extract to function' capability through the code action. When you select the code range to refactor, find a light bulb appearing (💡 ) near the selected region. Click it.

You can also bind a key short cut for refactor.extract following this guide: https://code.visualstudio.com/docs/getstarted/keybindings#_custom-keybindings-for-refactorings
But I am currently not sure yet the refactorings action naming of gopls is stable before gopls v1.0.

@stamblerre Is this mapping for the code action kind stable? I think this should be refactor.extract.function but not sure. Once code action kinds & command names gopls uses become stable, I think we need to document and use them for "Go: Extract to function" implementation.

[luca-battistelli]

Didn't notice the lightbulb! Thanks for the help 🙂

[stamblerre]

@stamblerre Is this mapping for the code action kind stable? I think this should be refactor.extract.function but not sure. Once code action kinds & command names gopls uses become stable, I think we need to document and use them for "Go: Extract to function" implementation.

I don't think we have the refactor.extract.function kind yet, but we can add it. We can try to address this when we change the command names (golang/go#41187).

[stamblerre]

Looks like this has been resolved--closing.