Go: cmd/gofmt: ignore vendor directory

[moznion]

Go's dependency management mechanism treats vendor directory specially to import external packages.
Currently, the gofmt command formats files even if those are managed under the vendor.
I think gofmt command should ignore the files under the vendor.

How does it feel?

(I wrote PoC patch here: https://github.com/golang/go/compare/master...moznion:gofmt_ignore_vendor_dir?expand=1)

[mvdan]

Have you tried go fmt? gofmt works on files and directories, not packages, so I'm not sure if it should treat vendor directories in a special way.

[mvdan]

/cc @griesemer

[moznion]

Yes, I tried to use (and also I'm using) go fmt command. It usually works no problems.
However, in my understand go fmt is a subset of gofmt command so go fmt is limited in function compared with "gofmt".

Actually, go fmt --help said as follows:

To run gofmt with specific options, run gofmt itself.

Therefore, I feel it is convenient if gofmt also ignores the vendor (or provide such an option).

[robpike]

It is not a subset, it is a wrapper. The important difference between go fmt and gofmt is the list of packages passed to the binary by go fmt, a list that for example excludes vendored packages.

[superstas]

In addition to the discussion above.
gofmt is able to simplify code, that's a terrific feature.

There is need for formating and simplification code at the same time ( excluding vendor ) .
It would be great to enable somehow the simplification feature in go fmt in that case.

[moznion]

It is not a subset, it is a wrapper. The important difference between go fmt and gofmt is the list of packages passed to the binary by go fmt, a list that for example excludes vendored packages.

Yes, it’s right. My expression was wrong, but I understand the behavior of both.

There is need for formating and simplification code at the same time ( excluding vendor ) .
It would be great to enable somehow the simplification feature in go fmt in that case.

That is a good point.
I think that it is good if the function of the go fmt is expanded with options or other ways. I don't have a reason to stick to gofmt.
If there are plans to make such changes, I have an intention to contribute to it.
(Additionally, if that is the case; I feel I want a dryrun option for the go fmt command)

[robpike]

If there is a resolution to this, it should be to let go fmt have access to all the flags of gofmt, not to change gofmt to track changes in the go command.

[moznion]

If there is a resolution to this, it should be to let go fmt have access to all the flags of gofmt, not to change gofmt to track changes in the go command.

I agree this.
I tried writing a PcC code based on this opinion: https://github.com/golang/go/compare/master...moznion:fmt_gofmt_flag?expand=1

[superstas]

@moznion could you please send your changes using regular flow, otherwise I'm afraid it wouldn't be reviewed
https://golang.org/doc/contribute.html

[moznion]

@superstas Sure, I'll do that.

[gopherbot]

Change https://golang.org/cl/70030 mentions this issue: cmd/gofmt: Make all of gofmt's functions to be available fromgo fmtcommand

[rsc]

I really hope that vendor directories will diminish in importance once proper package management arrives. Let's just not do anything special here for gofmt of vendor directories.