Depguard

A Go linter that checks package imports are in a list of acceptable packages. This allows you to allow imports from a whole organization or only allow specific packages within a repository.

Install

go get github.com/OpenPeeDeeP/depguard/v2

Config

The Depguard binary looks for a file named ^\.?depguard\.(yaml|yml|json|toml)$ in the current current working directory. Examples include (.depguard.yml or depguard.toml).

The following is an example configuration file.

{
  "main": {
    "files": [
      "$all",
      "!$test"
    ],
    "allow": [
      "$gostd",
      "github.com/OpenPeeDeeP"
    ],
    "deny": {
      "reflect": "Who needs reflection",
    }
  },
  "tests": {
    "files": [
      "$test"
    ],
    "deny": {
      "github.com/stretchr/testify": "Please use standard library for tests"
    }
  }
}

• The top level is a map of lists. The key of the map is a name that shows up in the linter's output.
• files - list of file globs that will match this list of settings to compare against
• allow - list of allowed packages
• deny - map of packages that are not allowed where the value is a suggestion

Files are matched using Globs. If the files list is empty, then all files will match that list. Prefixing a file with an exclamation mark ! will put that glob in a "don't match" list. A file will match a list if it is allowed and not denied.

Should always prefix a file glob with **/ as files are matched against absolute paths.

Allow is a prefix of packages to allow. A dollar sign $ can be used at the end of a package to specify it must be exact match only.

Deny is a map where the key is a prefix of the package to deny, and the value is a suggestion on what to use instead. A dollar sign $ can be used at the end of a package to specify it must be exact match only.

A Prefix List just means that a package will match a value, if the value is a prefix of the package. Example github.com/OpenPeeDeeP/depguard package will match a value of github.com/OpenPeeDeeP but won't match github.com/OpenPeeDeeP/depguard/v2.

Variables

There are variable replacements for each type of list (file or package). This is to reduce repetition and tedious behaviors.

File Variables

you can still use and exclamation mark ! in front of a variable to say not to use it. Example !$test will match any file that is not a go test file.

• $all - matches all go files
• $test - matches all go test files

Package Variables

• $gostd - matches all of go's standard library (Pulled from GOROOT)

Example Configs

Below:

• non-test go files will match Main and test go files will match Test.
• both allow all of go standard library except for the reflect package which will tell the user "Please don't use reflect package".
• go test files are also allowed to use https://github.com/stretchr/testify package and any sub-package of it.

Main:
  files:
  - $all
  - "!$test"
  allow:
  - $gostd
  deny:
    reflect: Please don't use reflect package
Test:
  files:
  - $test
  allow:
  - $gostd
  - github.com/stretchr/testify
  deny:
    reflect: Please don't use reflect package

Below:

• All go files will match Main
• Go files in internal will match both Main and Internal

Main:
  files:
  - $all
Internal:
  files:
  - "**/internal/**/*.go"

Below:

• All packages are allowed except for github.com/OpenPeeDeeP/depguard. Though github.com/OpenPeeDeeP/depguard/v2 and github.com/OpenPeeDeeP/depguard/somepackage would be allowed.

Main:
  deny:
  - github.com/OpenPeeDeeP/depguard$

Golangci-lint

This linter was built with Golangci-lint in mind. It is compatible and read their docs to see how to implement all their linters, including this one.