x/tools/gopls: integration testing may not test cases with old go versions

[hyangah]

The go directive in gopls's go.mod is set to 1.23.1 per #65917.
The assumption is that gopls built with go1.23.1+ can be still used to
analyze codebase with slightly older go versions. (e.g. go1.22.x, go1.21.x)

Gopls integration tests run on workspaces created in temp directories
outside golang.org/x/tools/gopls module and their go.mod files have go
version old enough to prevent toolchain switch. With this setup, I hoped
running gopls tests on go1.X builders (X < 23) is sufficient to test our assumption.

But it looks like this is not true.

CL 404134 prepends GOROOT/bin to PATH in go test, as
mentioned in #68005.

In CL 616055 I attempted to verify the go version.

$ GOTOOLCHAIN=local go version
go version go1.22.6 darwin/amd64

$ go version
go version go1.23.1 darwin/amd64

$ go test ./internal/test/integration/workspace -run TestCheckGoVersion
--- FAIL: TestCheckGoVersion (0.02s)
    workspace_test.go:1287: /Users/hakim/sdk/go1.23.1/bin/go <nil>
    workspace_test.go:1288: go version in PATH = 23
...

$ go test ./internal/test/integration/workspace -run TestViewGoVersion
...
--- FAIL: TestViewGoVersion (0.28s)
    --- FAIL: TestViewGoVersion/default (0.28s)
        workspace_test.go:1320: SummarizeViews() mismatch (-want +got):
              []command.View{
              	{
              		... // 1 ignored and 2 identical fields
              		Folder:     "file:///var/folders/5p/zn7ykc111kn3lm09h_47mz2w001py5/T/gopls-te"...,
              		EnvOverlay: nil,
            - 		GoVersion:  "",
            + 		GoVersion:  "go1.23.1",
              	},
              }
              ...

I don't know how we can recover the original PATH inside tests reliably.

go test also sets GOROOT environment variable, too, but we can unset it.

@golang/tools-team

[gabyhelp]

Related Issues and Documentation

• x/tools/gopls: decide on a long-term testing strategy for integration with older Go commands (and GOPACKAGESDRIVERs?) #69321
• x/tools/gopls: incorrectly detecting go version #56465 (closed)
• x/tools/gopls/test/debug: test fails when run in the module cache #59841 (closed)
• x/tools/gopls: log errors during `gopls check` #35564 (closed)
• proxy.golang.org: update to Go 1.13.3 to pick up the fix for #34477 #34991 (closed)
• golang.org/x/tools/gopls declares a broken dependency on golang.org/x/[email protected] #64995 (closed)
• x/tools/gopls: Error for version 0.14.0 with "gopls version" command #63803 (closed)
• x/build/cmd/golangbuild: disable GOTOOLCHAIN=local for the x/tools/gopls module #67749 (closed)
• x/tools/go/packages: use the correct go version for the analyzed project #68495
• x/tools/gopls: when using go.work in GOROOT, "gopls requires a module at the root of your workspace" #48022 (closed)

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

[findleyr]

Thanks for investigating! This definitely needs to be fixed (see also #69321).