importorder

README

ImportOrder

ImportOrder is a Golang linter that detects misordered imports given a certain pattern set.

For example, let's say you run the following importorder command:

./importorder -patterns="STDLIB github.com/m3db/m3coordinator github.com/m3db EXTERNAL" path/to/directory

This will make sure that your import groups (in path/to/directory) start with all Go standard library imports, followed by imports in the package github.com/m3db/m3coordinator, followed by all imports in the github.com/m3db package, and finally all external/third party packages.

In other words, this block will succeed:

import (
	"context"
	"time"

	"github.com/m3db/m3coordinator/errors"
	"github.com/m3db/m3coordinator/policy/resolver"

	"github.com/m3db/m3db/client"
	"github.com/m3db/m3x/ident"
)

And this will fail because context should belong in the first group with the other standard library import:

import (
	"time"

	"github.com/m3db/m3coordinator/errors"
	"context"
	"github.com/m3db/m3coordinator/policy/resolver"

	"github.com/m3db/m3db/client"
	"github.com/m3db/m3x/ident"
)

There are a few notes to point out:

1. If you are going to have two patterns where one is a subset of the other (e.g. github.com/m3db/m3coordinator and github.com/m3db), make sure that you provide the more specific one first. Otherwise, the linter will provide inaccurate results.
2. If you want to see exactly how the imports should look like as opposed to just getting an error, set the verbose flag to true (e.g. ./importorder -patterns="STDLIB github.com/m3db/m3coordinator github.com/m3db EXTERNAL" -verbose=true path/to/directory)
3. If you want to specify Go's standard library imports, use "STDLIB", and if you want to have a catch-all, use "EXTERNAL" (for all other third party/external packages)

Gometalinter integration

importorder is designed to integrate with gometalinter. To add it to the list of active linters, make sure importorder is installed, and then modify the .metalinter.json file to add "importorder" to the "Enable" array and also add it to the "Linters" object.

Example:

{
  "Linters": {
    "importorder": {
      "Command": "importorder -patterns=\"STDLIB github.com/m3db/m3coordinator github.com/m3db EXTERNAL\"",
      "Pattern": "PATH:LINE:MESSAGE"
    },
  },
  "Enable":
    [ "importorder" ],
}

Installation

go get -u github.com/m3db/build-tools/linters/importorder
cd $GOPATH/src/github.com/m3db/build-tools/linters/importorder
glide install -v
go install .

Usage

importorder -patterns="pattern_1 pattern_2 pattern_3 pattern_4" ./...

To view optional flags, run:

importorder -h

Note that the importorder package interprets path arguments and build tags the same way the standard Go toolchain does.

Development

1. Clone this repo into your $GOPATH
2. Make sure you have glide installed
3. Run glide install
4. Modify the code, add a new test file to the testdata directory, and update the testcases in main_test.go

Running the tests

go test <PATH_TO_IMPORTORDER_IN_YOUR_$GOPATH>