x/tools/gopls: inaccurate functionality for import with package name mismatching its path

[findleyr]

Reported in slack: gopls offers inaccurate functionality when importing github.com/wagslane/go-rabbitmq, which has the package name "rabbitmq". Completion is inaccurate, and import statements get removed on save:

@hyangah points out that this only happens when the module is not yet required by the go.mod. This is therefore probably a chicken-and-egg problem, but one that can be quite confusing for our users.

[hyangah]

@hyangah points out that this only happens when the module is not yet required by the go.mod. This is therefore probably a chicken-and-egg problem, but one that can be quite confusing for our users.

I was late in reading the slack - more confusion: the user reported that the user's code builds and there is no vet error. If the module wasn't required in the go.mod file, build and vet couldn't be successful. So, I am not sure if the user is seeing the same problem I observed. 🤔

[KoduIsGreat]

@hyangah, @findleyr Hi, I'm the user that reported this issue in slack.
to clarify, the package is required in the go.mod.

To me it seems like gopls is using the ending segment of the import path rather than the declared package identifier.

[findleyr]

@KoduIsGreat thank you for clarifying. I've updated the issue accordingly.

[muirdm]

I couldn't reproduce this. I tried various things but only ever saw completions for "rabbitmq" (never "go-rabbitmq"), which added the proper import and overall worked as expected. Are you certain that completion was coming from gopls?

AFAIK the unimported package completions first look at other imports in your workspace taking in to account declared package name, otherwise falling back to searching GOMODCACHE which also takes in to account declared package name by parsing a single file in each directory.

[KoduIsGreat]

If the completion wasn't coming from gopls, what else would it be coming from.

[muirdm]

I dunno, some other VS Code integrated tool. Anyway, can you give steps to reproduce?