README.md

How to add errorformat for new tool

1) Download errorformat CLI tool for debugging (optional)

go get -u github.com/reviewdog/errorformat/cmd/errorformat

2) Write errorformat for the target output

• errorformat doc: http://vimdoc.sourceforge.net/htmldoc/quickfix.html#errorformat

Note that https://github.com/reviewdog/errorformat doesn't support Vim regex, and efm-%> feature (currently). Other syntax are supported.

Example (add errorformat for golint)

Prepare output of golint.

$ golint ./... > golint.in

golint.in

golint.new.go:3:5: exported var V should have comment or be unexported
golint.new.go:5:5: exported var NewError1 should have comment or be unexported
golint.new.go:7:1: comment on exported function F should be of the form "F ..."
golint.new.go:11:1: comment on exported function F2 should be of the form "F2 ..."

Write errorformat for it.

$ errorformat "%f:%l:%c: %m" < golint.in
golint.new.go|3 col 5| exported var V should have comment or be unexported
golint.new.go|5 col 5| exported var NewError1 should have comment or be unexported
golint.new.go|7 col 1| comment on exported function F should be of the form "F ..."
golint.new.go|11 col 1| comment on exported function F2 should be of the form "F2 ..."

3) Add errorformat with test

Add errorformat in fmts/{lang}.go, where {lang} is target programming language (or filetype) of the command.

fmts/go.go

func init() {
	const lang = "go"

  // ...

	register(&Fmt{
		Name: "golint",
		Errorformat: []string{
			`%f:%l:%c: %m`,
		},
		Description: "linter for Go source code",
		URL:         "https://github.com/golang/lint",
		Language:    lang,
	})

  // ...
}

Required fields are self descriptive. See https://godoc.org/github.com/reviewdog/errorformat/fmts#Fmt

fmts/testdata/golint.in

Add input file in fmts/testdata/{name}.in

golint.new.go:3:5: exported var V should have comment or be unexported
golint.new.go:5:5: exported var NewError1 should have comment or be unexported
golint.new.go:7:1: comment on exported function F should be of the form "F ..."
golint.new.go:11:1: comment on exported function F2 should be of the form "F2 ..."

I also recommend to add resource code to reproduce this input file in fmts/testdata/resources/{lang}/{name}

fmts/testdata/golint.ok

Add ok file in fmts/testdata/{name}.ok

golint.new.go|3 col 5| exported var V should have comment or be unexported
golint.new.go|5 col 5| exported var NewError1 should have comment or be unexported
golint.new.go|7 col 1| comment on exported function F should be of the form "F ..."
golint.new.go|11 col 1| comment on exported function F2 should be of the form "F2 ..."

You can run test by go test ./...

4) go generate ./...

Run go generate ./... to update document file.

5) Open Pull-Request!