cmd/go: provide a convenient way to iterate all packages in go.work workspace

[hyangah]

go.work makes it easier to work with multiple modules.

Often users want to run tests or analysis for all packages in their workspace. For a single module case, this can be easily achieved by using ./... pattern. Currently, however, there is no equivalent of ./... in workspace mode. So users need to run go commands from inside of each individual module, or supply the paths for each module directories listed in go.work. (e.g. go test -v $(go list -f '{{.Dir}}/...' -m | xargs)).

We need to figure out how to offer ./...-equivalent behavior when working with `go.work.

My personal preference is to reuse./... (VSCode Go uses ./... pattern to implement workspace-wide test, lint, coverage computation, etc).

p.s. I noticed the issue about clarifying the meaning of ... in module mode is still open #37227

[katexochen]

go test -v $(go list -f '{{.Dir}}/...' -m | xargs)

This is especially not possible in CI, as the go.work file shouldn't be checked in (according to the proposal). To have a consistent solution, it would be great to solve this problem for modules in general, not only for repositories with a go.work file.

[seankhliao]

how would you decide what to include if you don't have a go.work file?

[katexochen]

how would you decide what to include if you don't have a go.work file?

I just would like to iterate over all sub modules, e.g., run all unit test in the active module and all sub modules.

[eighty4]

Having a go.work file for local workflow setup is a use case, but I am setting up a project that I definitely plan on adding my go.work file to my committed sources. There's not much value add, other than enabling a fork to engage in development without having to recreate an identical go.work file, but that's only because the workspace feature doesn't have workflows baked into the tooling. It seems like a huge miss to add workspaces and not have a way to run go test across all the workspace modules or to be able to run go get for a module of a workspace without using cd.

I'm not familiar with the internals of go's community. Are they accepting of proposals and PRs?

[katexochen]

@eighty4 If you have go.work checked in, you can easily list all modules with

go list -f '{{.Dir}}' -m | xargs

You could then do something like

mods=$(go list -f '{{.Dir}}' -m | xargs)
for mod in $mods; do
            (cd "$mod"; go test ./...)
done

Not perfect, but works. It's much more pain if you don't check in go.work (as recommended by the documentation) and want to do such thing...

[eighty4]

Sorry you had to repeat the answer for me. Works pretty well:

go list -f '{{.Dir}}' -m | xargs go test

[eighty4]

I don't see how I could achieve the same one liner for go mod tidy. Is it possible to achieve this with an xargs/pipe:

# workspace dir
go mod tidy
# cd for each module
cd composable
go mod tidy
cd ../git
go mod tidy
cd ../testutil
go mod tidy
cd ../util
go mod tidy

[seankhliao]

Reusing ./... for workspaces would clash if you had a module in the workspace root (use .).

Would ./.... (4 dots) be too subtle?

[katexochen]

Would ./.... (4 dots) be too subtle?

Yes, I think this would be too subtle. :( But I also lack a better idea. Maybe a flag, to make commands workspace aware, in the same way -m makes them module aware?

[eighty4]

I don't know what the ./... and go test [packages] do or are for. I could only get pattern matching to work with go test such as go test my_test.go. Do you have to specify go test github.com/fullyqualified/modulepath to test a package? ./... seemed to have no effect.

[eighty4]

What's an example of a module aware command with -m?

[cyrusv]

4 dots is interesting idea--maybe a little more obvious would be ./.../...?

An issue with these shell scripts is that you don't get an aggregated coverage report.

I am curious about the framing of the issue here: Is this a gap in workspace, or a gap in go test? My understanding is that workspace is an optional, local convenience. The ability to run all tests incl submodules, I think, should work whether or not an individual chooses to use workspaces feature. Is that a fair understanding?

[katexochen]

The ability to run all tests incl submodules, I think, should work whether or not an individual chooses to use workspaces feature

I agree with that. Notice that this is a general issue with go tooling, not only for running tests. I'd also like to go tidy all submodules etc.

[katexochen]

mods=$(go list -f '{{.Dir}}' -m | xargs)
for mod in $mods; do
(cd "$mod"; go test ./...)
done

With Go 1.20, the new -C flag can be used to simplify this to

mods=$(go list -f '{{.Dir}}' -m)
for mod in $mods; do
            go test -C "$mod" ./...
done

This also works for go tidy @eighty4 :

mods=$(go list -f '{{.Dir}}' -m)
for mod in $mods; do
            go mod tidy -C "$mod"
done

[cyrusv]

@seankhliao, is there agreement from the maintainers that

• There is a gap in go tooling any time "./..." is allowed where a user may want to specify additionally to apply the tool to submodules
• The fix should work whether or not someone uses workspaces
  ?

If there is agreement, then what are next steps?
Do we need a formal proposal for what the syntax should be for the fix, then a PR to implement?
I'm happy to take action if the maintainers give some guidance -- I have not yet contributed to golang before!

[cyrusv]

bump @bcmills, any advice on how to advance a solution?

[seankhliao]

My opinion would be that no pattern should cross between unrelated module dependency graphs, which can produce confusing / conflicting information on dependency resolution.

[hyangah]

IMHO the key idea of go.work is to make the selected modules "related" and the go command runs the version selection algorithm on the combined modules and already builds a very different dependency graph.
If users want to preserve the separation, they can do GOWORK=off go test ./... from their desired directory.

[cyrusv]

@hyangah, your proposal seems sensible and consistent to me. In that case, it sounds like your are proposing to evolve go.work to be strongly recommended tool for structuring a multi-module project, and checked into version control to provide consistency. Is that a fair understanding? This way, @seankhliao's preference to keep modules separate is held. @hyangah, how do you propose to meet this requirement from the Workspaces proposal?

go.work files should not be checked into version control repos containing modules so that the go.work file in a module does not end up overriding the configuration a user created themselves outside of the module. The go.work documentation should contain clear warnings about this.

However, if we are unwilling to formalize Workspaces to be strongly recommended for multi-module projects, then I'm not sure it makes sense.

[eighty4]

I think it works great this way.

Workspaces should evolve to simplify the go mod tidy upkeep across all modules of a workspace with a command that performs mod tidy in each workspace module, with each tidy being its own independent operation. The statement proposal's wording feels like a hang up.

[samherrmann]

@katexochen, the following one-liners appear to work:

• test:

  go list -f '{{.Dir}}/...' -m | xargs go test

• tidy:

  go list -f '{{.Dir}}' -m | xargs -L1 go mod tidy -C

[eighty4]

Should it be

go work sync
go list -f '{{.Dir}}' -m | xargs -L1 go mod tidy -C
go work sync
go list -f '{{.Dir}}' -m | xargs -L1 go mod tidy -C

or

go list -f '{{.Dir}}' -m | xargs -L1 go mod tidy -C
go work sync
go list -f '{{.Dir}}' -m | xargs -L1 go mod tidy -C

?