GolangCI-Lint is a linters aggregator. It's fast: on average 5 times faster than gometalinter. It's easy to integrate and use, has nice output and has a minimum number of false positives. It supports go modules.
GolangCI-Lint has integrations with VS Code, GNU Emacs, Sublime Text.
Follow the news and releases on our twitter and our blog.
Sponsored by GolangCI.com: SaaS service for running linters on GitHub pull requests. Free for Open Source.
- GolangCI-Lint
Short 1.5 min video demo of analyzing beego.
Most installations are done for CI (e.g. Travis CI, CircleCI). It's important to have reproducible CI:
don't start to fail all builds at the same time. With golangci-lint this can happen if you
use deprecated option --enable-all
and a new linter is added or even without --enable-all
: when one upstream linter is upgraded.
It's highly recommended to install a specific version of golangci-lint available on the releases page.
Here is the recommended way to install golangci-lint v1.21.0:
# binary will be $(go env GOPATH)/bin/golangci-lint
curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.21.0
# or install it into ./bin/
curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s v1.21.0
# In alpine linux (as it does not come with curl by default)
wget -O- -nv https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s v1.21.0
golangci-lint --version
It is advised that you periodically update version of golangci-lint as the project is under active development and is constantly being improved. For any problems with golangci-lint, check out recent GitHub issues and update if needed.
You can also install a binary release on macOS using brew:
brew install golangci/tap/golangci-lint
brew upgrade golangci/tap/golangci-lint
docker run --rm -v $(pwd):/app -w /app golangci/golangci-lint:v1.21.0 golangci-lint run -v
Please, do not install golangci-lint
by go get
:
go.mod
replacement directive doesn't apply. It means you will be using patched version ofgolangci-lint
.- it's much slower than binary installation
- its stability depends on your Go version (e.g. on this compiler Go <= 1.12 bug).
- it's not guaranteed to work: e.g. we've encountered a lot of issues with Go modules hashes.
- it allows installation from
master
branch which can't be considered stable.
The following companies/products use golangci-lint:
- Red Hat OpenShift
- Yahoo
- IBM
- Xiaomi
- Samsung
- Arduino
- Eclipse Foundation
- WooCart
- Percona
- Serverless
- ScyllaDB
- NixOS
- The New York Times
- Istio
- SoundCloud
- Mattermost
The following great projects use golangci-lint:
- alecthomas/participle
- asobti/kube-monkey
- banzaicloud/pipeline
- caicloud/cyclone
- getantibody/antibody
- goreleaser/goreleaser
- go-swagger/go-swagger
- kubeedge/kubeedge
- kubernetes-sigs/kustomize
- dunglas/mercure
- posener/complete
- segmentio/terraform-docs
- tsuru/tsuru
- twpayne/chezmoi
- virtual-kubelet/virtual-kubelet
- xenolf/lego
- y0ssar1an/q
To run golangci-lint execute:
golangci-lint run
It's an equivalent of executing:
golangci-lint run ./...
You can choose which directories and files to analyze:
golangci-lint run dir1 dir2/... dir3/file1.go
Directories are NOT analyzed recursively. To analyze them recursively append /...
to their path.
GolangCI-Lint can be used with zero configuration. By default the following linters are enabled:
$ golangci-lint help linters
Enabled by default linters:
deadcode: Finds unused code [fast: true, auto-fix: false]
errcheck: Errcheck is a program for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases [fast: true, auto-fix: false]
gosimple (megacheck): Linter for Go source code that specializes in simplifying a code [fast: true, auto-fix: false]
govet (vet, vetshadow): Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string [fast: true, auto-fix: false]
ineffassign: Detects when assignments to existing variables are not used [fast: true, auto-fix: false]
staticcheck (megacheck): Staticcheck is a go vet on steroids, applying a ton of static analysis checks [fast: true, auto-fix: false]
structcheck: Finds unused struct fields [fast: true, auto-fix: false]
typecheck: Like the front-end of a Go compiler, parses and type-checks Go code [fast: true, auto-fix: false]
unused (megacheck): Checks Go code for unused constants, variables, functions and types [fast: false, auto-fix: false]
varcheck: Finds unused global variables and constants [fast: true, auto-fix: false]
and the following linters are disabled by default:
$ golangci-lint help linters
...
Disabled by default linters:
bodyclose: checks whether HTTP response body is closed successfully [fast: true, auto-fix: false]
depguard: Go linter that checks if package imports are in a list of acceptable packages [fast: true, auto-fix: false]
dogsled: Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f()) [fast: true, auto-fix: false]
dupl: Tool for code clone detection [fast: true, auto-fix: false]
funlen: Tool for detection of long functions [fast: true, auto-fix: false]
gochecknoglobals: Checks that no globals are present in Go code [fast: true, auto-fix: false]
gochecknoinits: Checks that no init functions are present in Go code [fast: true, auto-fix: false]
gocognit: Computes and checks the cognitive complexity of functions [fast: true, auto-fix: false]
goconst: Finds repeated strings that could be replaced by a constant [fast: true, auto-fix: false]
gocritic: The most opinionated Go source code linter [fast: true, auto-fix: false]
gocyclo: Computes and checks the cyclomatic complexity of functions [fast: true, auto-fix: false]
godox: Tool for detection of FIXME, TODO and other comment keywords [fast: true, auto-fix: false]
gofmt: Gofmt checks whether code was gofmt-ed. By default this tool runs with -s option to check for code simplification [fast: true, auto-fix: true]
goimports: Goimports does everything that gofmt does. Additionally it checks unused imports [fast: true, auto-fix: true]
golint: Golint differs from gofmt. Gofmt reformats Go source code, whereas golint prints out style mistakes [fast: true, auto-fix: false]
gomnd: An analyzer to detect magic numbers. [fast: true, auto-fix: false]
gosec (gas): Inspects source code for security problems [fast: true, auto-fix: false]
interfacer: Linter that suggests narrower interface types [fast: true, auto-fix: false]
lll: Reports long lines [fast: true, auto-fix: false]
maligned: Tool to detect Go structs that would take less memory if their fields were sorted [fast: true, auto-fix: false]
misspell: Finds commonly misspelled English words in comments [fast: true, auto-fix: true]
nakedret: Finds naked returns in functions greater than a specified function length [fast: true, auto-fix: false]
prealloc: Finds slice declarations that could potentially be preallocated [fast: true, auto-fix: false]
scopelint: Scopelint checks for unpinned variables in go programs [fast: true, auto-fix: false]
stylecheck: Stylecheck is a replacement for golint [fast: true, auto-fix: false]
unconvert: Remove unnecessary type conversions [fast: true, auto-fix: false]
unparam: Reports unused function parameters [fast: true, auto-fix: false]
whitespace: Tool for detection of leading and trailing whitespace [fast: true, auto-fix: true]
wsl: Whitespace Linter - Forces you to use empty lines! [fast: true, auto-fix: false]
Pass -E/--enable
to enable linter and -D/--disable
to disable:
golangci-lint run --disable-all -E errcheck
-
Go for Visual Studio Code. Recommended settings for VS Code are:
"go.lintTool":"golangci-lint", "go.lintFlags": [ "--fast" ]
Using it in an editor without
--fast
can freeze your editor. Golangci-lint automatically discovers.golangci.yml
config for edited file: you don't need to configure it in VS Code settings. -
Sublime Text - plugin for SublimeLinter.
-
GoLand
- Configure File Watcher with arguments
run --print-issued-lines=false $FileDir$
. - Predefined File Watcher will be added in issue.
- Configure File Watcher with arguments
-
GNU Emacs
-
Vim
- vim-go
- syntastic merged pull request with golangci-lint support
- ale merged pull request with golangci-lint support
-
Atom - go-plus supports golangci-lint.
golangci-lint
can generate bash completion file.
There are two versions of bash-completion
, v1 and v2. V1 is for Bash 3.2 (which is the default on macOS), and v2 is for Bash 4.1+. The golangci-lint
completion script doesn’t work correctly with bash-completion v1 and Bash 3.2. It requires bash-completion v2 and Bash 4.1+. Thus, to be able to correctly use golangci-lint
completion on macOS, you have to install and use Bash 4.1+ (instructions). The following instructions assume that you use Bash 4.1+ (that is, any Bash version of 4.1 or newer).
Install bash-completion v2
:
brew install bash-completion@2
echo 'export BASH_COMPLETION_COMPAT_DIR="/usr/local/etc/bash_completion.d"' >>~/.bashrc
echo '[[ -r "/usr/local/etc/profile.d/bash_completion.sh" ]] && . "/usr/local/etc/profile.d/bash_completion.sh"' >>~/.bashrc
exec bash # reload and replace (if it was updated) shell
type _init_completion && echo "completion is OK" # verify that bash-completion v2 is correctly installed
Add golangci-lint
bash completion:
echo 'source <(golangci-lint completion bash)' >>~/.bashrc
source ~/.bashrc
See kubectl instructions and don't forget to replace kubectl
with golangci-lint
.
GolangCI-Lint was created to fix the following issues with gometalinter
:
- Slow work:
gometalinter
usually works for minutes in average projects. GolangCI-Lint works 2-7x times faster by reusing work. - Huge memory consumption: parallel linters don't share the same program representation and can consume
n
times more memory (n
- concurrency). GolangCI-Lint fixes it by sharing representation and consumes 26% less memory. - Doesn't use real bounded concurrency: if you set it to
n
it can take up ton*n
threads because of forced threads in specific linters.gometalinter
can't do anything about it because it runs linters as black boxes in forked processes. In GolangCI-Lint we run all linters in one process and completely control them. Configured concurrency will be correctly bounded. This issue is important because you often want to set concurrency to the CPUs count minus one to ensure you do not freeze your PC and be able to work on it while analyzing code. - Lack of nice output. We like how the
gcc
andclang
compilers format their warnings: using colors, printing warning lines and showing the position in line. - Too many issues. GolangCI-Lint cuts a lot of issues by using default exclude list of common false-positives. By default, it has enabled smart issues processing: merge multiple issues for one line, merge issues with the same text or from the same linter. All of these smart processors can be configured by the user.
- Integration into large codebases. A good way to start using linters in a large project is not to fix a plethora
of existing issues, but to set up CI and fix only issues in new commits. You can use
revgrep
for it, but it's yet another utility to install and configure. Withgolangci-lint
it's much easier:revgrep
is already built intogolangci-lint
and you can use it with one option (-n, --new
or--new-from-rev
). - Installation. With
gometalinter
, you need to run a linters installation step. It's easy to forget this step and end up with stale linters. It also complicates CI setup. GolangCI-Lint requires no installation of linters. - Yaml or toml config. Gometalinter's JSON isn't convenient for config files.
- It will be much slower because
golangci-lint
runs all linters in parallel and shares 50-80% of linters work. - It will have less control and more false-positives: some linters can't be properly configured without hacks.
- It will take more time because of different usages and need of tracking of versions of
n
linters.
Benchmarks were executed on MacBook Pro (Retina, 13-inch, Late 2013), 2,4 GHz Intel Core i5, 8 GB 1600 MHz DDR3.
It has 4 cores and concurrent linting as a default consuming all cores.
Benchmark was run (and measured) automatically, see the code
here (BenchmarkWithGometalinter
).
We measure peak memory usage (RSS) by tracking of processes RSS every 5 ms.
We compare golangci-lint and gometalinter in default mode, but explicitly enable all linters because of small differences in the default configuration.
$ golangci-lint run --no-config --issues-exit-code=0 --timeout=30m \
--disable-all --enable=deadcode --enable=gocyclo --enable=golint --enable=varcheck \
--enable=structcheck --enable=maligned --enable=errcheck --enable=dupl --enable=ineffassign \
--enable=interfacer --enable=unconvert --enable=goconst --enable=gosec --enable=megacheck
$ gometalinter --deadline=30m --vendor --cyclo-over=30 --dupl-threshold=150 \
--exclude=<default golangci-lint excludes> --skip=testdata --skip=builtin \
--disable-all --enable=deadcode --enable=gocyclo --enable=golint --enable=varcheck \
--enable=structcheck --enable=maligned --enable=errcheck --enable=dupl --enable=ineffassign \
--enable=interfacer --enable=unconvert --enable=goconst --enable=gosec --enable=megacheck
./...
Repository | GolangCI Time | GolangCI Is Faster than Gometalinter | GolangCI Memory | GolangCI eats less memory than Gometalinter |
---|---|---|---|---|
gometalinter repo, 4 kLoC | 6s | 6.4x | 0.7GB | 33% |
self-repo, 4 kLoC | 12s | 7.5x | 1.2GB | 41% |
beego, 50 kLoC | 10s | 4.2x | 1.4GB | 9% |
hugo, 70 kLoC | 15s | 6.1x | 1.6GB | 44% |
consul, 127 kLoC | 58s | 4x | 2.7GB | 41% |
terraform, 190 kLoC | 2m13s | 1.6x | 4.8GB | 0% |
go-ethereum, 250 kLoC | 33s | 5x | 3.6GB | 0% |
go source ($GOROOT/src ), 1300 kLoC |
2m45s | 2x | 4.7GB | 0% |
On average golangci-lint is 4.6 times faster than gometalinter. Maximum difference is in the self-repo: 7.5 times faster, minimum difference is in terraform source code repo: 1.8 times faster.
On average golangci-lint consumes 26% less memory.
Golangci-lint directly calls linters (no forking) and reuses 80% of work by parsing program only once. Read this section for details.
A trade-off between memory usage and execution time can be controlled by GOGC
environment variable.
Less GOGC
values trigger garbage collection more frequently and golangci-lint consumes less memory and more CPU. Below is the trade-off table for running on this repo:
GOGC |
Peak Memory, GB | Executon Time, s |
---|---|---|
5 |
1.1 | 60 |
10 |
1.1 | 34 |
20 |
1.3 | 25 |
30 |
1.6 | 20.2 |
50 |
2.0 | 17.1 |
80 |
2.2 | 14.1 |
100 (default) |
2.2 | 13.8 |
off |
3.2 | 9.3 |
-
Work sharing The key difference with gometalinter is that golangci-lint shares work between specific linters (golint, govet, ...). We don't fork to call specific linter but use its API. For small and medium projects 50-90% of work between linters can be reused.
-
load
[]*packages.Package
bygo/packages
onceWe load program (parsing all files and type-checking) only once for all linters. For the most of linters it's the most heavy operation: it takes 5 seconds on 8 kLoC repo and 11 seconds on
$GOROOT/src
. -
build
ssa.Program
onceSome linters (megacheck, interfacer, unparam) work on SSA representation. Building of this representation takes 1.5 seconds on 8 kLoC repo and 6 seconds on
$GOROOT/src
. -
parse source code and build AST once
Parsing one source file takes 200 us on average. Parsing of all files in
$GOROOT/src
takes 2 seconds. Currently we parse each file more than once because it's not the bottleneck. But we already save a lot of extra parsing. We're planning to parse each file only once. -
walk files and directories once
It takes 300-1000 ms for
$GOROOT/src
.
-
-
Smart linters scheduling
We schedule linters by a special algorithm which takes estimated execution time into account. It allows to save 10-30% of time when one of heavy linters (megacheck etc) is enabled.
-
Don't fork to run shell commands
All linters are vendored in the /vendor
folder: their version is fixed, they are builtin
and you don't need to install them separately.
To see a list of supported linters and which linters are enabled/disabled:
golangci-lint help linters
- govet - Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string
- errcheck - Errcheck is a program for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases
- staticcheck - Staticcheck is a go vet on steroids, applying a ton of static analysis checks
- unused - Checks Go code for unused constants, variables, functions and types
- gosimple - Linter for Go source code that specializes in simplifying a code
- structcheck - Finds unused struct fields
- varcheck - Finds unused global variables and constants
- ineffassign - Detects when assignments to existing variables are not used
- deadcode - Finds unused code
- typecheck - Like the front-end of a Go compiler, parses and type-checks Go code
- bodyclose - checks whether HTTP response body is closed successfully
- golint - Golint differs from gofmt. Gofmt reformats Go source code, whereas golint prints out style mistakes
- stylecheck - Stylecheck is a replacement for golint
- gosec - Inspects source code for security problems
- interfacer - Linter that suggests narrower interface types
- unconvert - Remove unnecessary type conversions
- dupl - Tool for code clone detection
- goconst - Finds repeated strings that could be replaced by a constant
- gocyclo - Computes and checks the cyclomatic complexity of functions
- gocognit - Computes and checks the cognitive complexity of functions
- gofmt - Gofmt checks whether code was gofmt-ed. By default this tool runs with -s option to check for code simplification
- goimports - Goimports does everything that gofmt does. Additionally it checks unused imports
- maligned - Tool to detect Go structs that would take less memory if their fields were sorted
- depguard - Go linter that checks if package imports are in a list of acceptable packages
- misspell - Finds commonly misspelled English words in comments
- lll - Reports long lines
- unparam - Reports unused function parameters
- dogsled - Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f())
- nakedret - Finds naked returns in functions greater than a specified function length
- prealloc - Finds slice declarations that could potentially be preallocated
- scopelint - Scopelint checks for unpinned variables in go programs
- gocritic - The most opinionated Go source code linter
- gochecknoinits - Checks that no init functions are present in Go code
- gochecknoglobals - Checks that no globals are present in Go code
- godox - Tool for detection of FIXME, TODO and other comment keywords
- funlen - Tool for detection of long functions
- whitespace - Tool for detection of leading and trailing whitespace
- wsl - Whitespace Linter - Forces you to use empty lines!
- gomnd - An analyzer to detect magic numbers.
The config file has lower priority than command-line options. If the same bool/string/int option is provided on the command-line and in the config file, the option from command-line will be used. Slice options (e.g. list of enabled/disabled linters) are combined from the command-line and config file.
To see a list of enabled by your configuration linters:
golangci-lint linters
golangci-lint run -h
Usage:
golangci-lint run [flags]
Flags:
--out-format string Format of output: colored-line-number|line-number|json|tab|checkstyle|code-climate|junit-xml (default "colored-line-number")
--print-issued-lines Print lines of code with issue (default true)
--print-linter-name Print linter name in issue line (default true)
--modules-download-mode string Modules download mode. If not empty, passed as -mod=<mode> to go tools
--issues-exit-code int Exit code when issues were found (default 1)
--build-tags strings Build tags
--timeout duration Timeout for total work (default 1m0s)
--tests Analyze tests (*_test.go) (default true)
--print-resources-usage Print avg and max memory usage of golangci-lint and total time
-c, --config PATH Read config from file path PATH
--no-config Don't read config
--skip-dirs strings Regexps of directories to skip
--skip-dirs-use-default Use or not use default excluded directories:
- (^|/)vendor($|/)
- (^|/)third_party($|/)
- (^|/)testdata($|/)
- (^|/)examples($|/)
- (^|/)Godeps($|/)
- (^|/)builtin($|/)
(default true)
--skip-files strings Regexps of files to skip
-E, --enable strings Enable specific linter
-D, --disable strings Disable specific linter
--disable-all Disable all linters
-p, --presets strings Enable presets (bugs|complexity|format|performance|style|unused) of linters. Run 'golangci-lint linters' to see them. This option implies option --disable-all
--fast Run only fast linters from enabled linters set (first run won't be fast)
-e, --exclude strings Exclude issue by regexp
--exclude-use-default Use or not use default excludes:
# errcheck: Almost all programs ignore errors on these functions and in most cases it's ok
- Error return value of .((os\.)?std(out|err)\..*|.*Close|.*Flush|os\.Remove(All)?|.*printf?|os\.(Un)?Setenv). is not checked
# golint: Annoying issue about not having a comment. The rare codebase has such comments
- (comment on exported (method|function|type|const)|should have( a package)? comment|comment should be of the form)
# golint: False positive when tests are defined in package 'test'
- func name will be used as test\.Test.* by other packages, and that stutters; consider calling this
# govet: Common false positives
- (possible misuse of unsafe.Pointer|should have signature)
# staticcheck: Developers tend to write in C-style with an explicit 'break' in a 'switch', so it's ok to ignore
- ineffective break statement. Did you mean to break out of the outer loop
# gosec: Too many false-positives on 'unsafe' usage
- Use of unsafe calls should be audited
# gosec: Too many false-positives for parametrized shell calls
- Subprocess launch(ed with variable|ing should be audited)
# gosec: Duplicated errcheck checks
- G104
# gosec: Too many issues in popular repos
- (Expect directory permissions to be 0750 or less|Expect file permissions to be 0600 or less)
# gosec: False positive is triggered by 'src, err := ioutil.ReadFile(filename)'
- Potential file inclusion via variable
(default true)
--max-issues-per-linter int Maximum issues count per one linter. Set to 0 to disable (default 50)
--max-same-issues int Maximum count of issues with the same text. Set to 0 to disable (default 3)
-n, --new Show only new issues: if there are unstaged changes or untracked files, only those changes are analyzed, else only changes in HEAD~ are analyzed.
It's a super-useful option for integration of golangci-lint into existing large codebase.
It's not practical to fix all existing issues at the moment of integration: much better to not allow issues in new code.
For CI setups, prefer --new-from-rev=HEAD~, as --new can skip linting the current patch if any scripts generate unstaged files before golangci-lint runs.
--new-from-rev REV Show only new issues created after git revision REV
--new-from-patch PATH Show only new issues created in git patch with file path PATH
--fix Fix found issues (if it's supported by the linter)
-h, --help help for run
Global Flags:
--color string Use color when printing; can be 'always', 'auto', or 'never' (default "auto")
-j, --concurrency int Concurrency (default NumCPU) (default 8)
--cpu-profile-path string Path to CPU profile output file
--mem-profile-path string Path to memory profile output file
--trace-path string Path to trace output file
-v, --verbose verbose output
--version Print version
GolangCI-Lint looks for config files in the following paths from the current working directory:
.golangci.yml
.golangci.toml
.golangci.json
GolangCI-Lint also searches for config files in all directories from the directory of the first analyzed path up to the root.
To see which config file is being used and where it was sourced from run golangci-lint with -v
option.
Config options inside the file are identical to command-line options. You can configure specific linters' options only within the config file (not the command-line).
There is a .golangci.example.yml
example
config file with all supported options, their description and default value:
# This file contains all available configuration options
# with their default values.
# options for analysis running
run:
# default concurrency is a available CPU number
concurrency: 4
# timeout for analysis, e.g. 30s, 5m, default is 1m
timeout: 1m
# exit code when at least one issue was found, default is 1
issues-exit-code: 1
# include test files or not, default is true
tests: true
# list of build tags, all linters use it. Default is empty list.
build-tags:
- mytag
# which dirs to skip: issues from them won't be reported;
# can use regexp here: generated.*, regexp is applied on full path;
# default value is empty list, but default dirs are skipped independently
# from this option's value (see skip-dirs-use-default).
skip-dirs:
- src/external_libs
- autogenerated_by_my_lib
# default is true. Enables skipping of directories:
# vendor$, third_party$, testdata$, examples$, Godeps$, builtin$
skip-dirs-use-default: true
# which files to skip: they will be analyzed, but issues from them
# won't be reported. Default value is empty list, but there is
# no need to include all autogenerated files, we confidently recognize
# autogenerated files. If it's not please let us know.
skip-files:
- ".*\\.my\\.go$"
- lib/bad.go
# by default isn't set. If set we pass it to "go list -mod={option}". From "go help modules":
# If invoked with -mod=readonly, the go command is disallowed from the implicit
# automatic updating of go.mod described above. Instead, it fails when any changes
# to go.mod are needed. This setting is most useful to check that go.mod does
# not need updates, such as in a continuous integration and testing system.
# If invoked with -mod=vendor, the go command assumes that the vendor
# directory holds the correct copies of dependencies and ignores
# the dependency descriptions in go.mod.
modules-download-mode: readonly|release|vendor
# output configuration options
output:
# colored-line-number|line-number|json|tab|checkstyle|code-climate, default is "colored-line-number"
format: colored-line-number
# print lines of code with issue, default is true
print-issued-lines: true
# print linter name in the end of issue text, default is true
print-linter-name: true
# all available settings of specific linters
linters-settings:
errcheck:
# report about not checking of errors in type assetions: `a := b.(MyStruct)`;
# default is false: such cases aren't reported by default.
check-type-assertions: false
# report about assignment of errors to blank identifier: `num, _ := strconv.Atoi(numStr)`;
# default is false: such cases aren't reported by default.
check-blank: false
# [deprecated] comma-separated list of pairs of the form pkg:regex
# the regex is used to ignore names within pkg. (default "fmt:.*").
# see https://github.com/kisielk/errcheck#the-deprecated-method for details
ignore: fmt:.*,io/ioutil:^Read.*
# path to a file containing a list of functions to exclude from checking
# see https://github.com/kisielk/errcheck#excluding-functions for details
exclude: /path/to/file.txt
funlen:
lines: 60
statements: 40
govet:
# report about shadowed variables
check-shadowing: true
# settings per analyzer
settings:
printf: # analyzer name, run `go tool vet help` to see all analyzers
funcs: # run `go tool vet help printf` to see available settings for `printf` analyzer
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Infof
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Warnf
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Errorf
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Fatalf
# enable or disable analyzers by name
enable:
- atomicalign
enable-all: false
disable:
- shadow
disable-all: false
golint:
# minimal confidence for issues, default is 0.8
min-confidence: 0.8
gofmt:
# simplify code: gofmt with `-s` option, true by default
simplify: true
goimports:
# put imports beginning with prefix after 3rd-party packages;
# it's a comma-separated list of prefixes
local-prefixes: github.com/org/project
gocyclo:
# minimal code complexity to report, 30 by default (but we recommend 10-20)
min-complexity: 10
gocognit:
# minimal code complexity to report, 30 by default (but we recommend 10-20)
min-complexity: 10
maligned:
# print struct with more effective memory layout or not, false by default
suggest-new: true
dupl:
# tokens count to trigger issue, 150 by default
threshold: 100
goconst:
# minimal length of string constant, 3 by default
min-len: 3
# minimal occurrences count to trigger, 3 by default
min-occurrences: 3
depguard:
list-type: blacklist
include-go-root: false
packages:
- github.com/sirupsen/logrus
packages-with-error-messages:
# specify an error message to output when a blacklisted package is used
github.com/sirupsen/logrus: "logging is allowed only by logutils.Log"
misspell:
# Correct spellings using locale preferences for US or UK.
# Default is to use a neutral variety of English.
# Setting locale to US will correct the British spelling of 'colour' to 'color'.
locale: US
ignore-words:
- someword
lll:
# max line length, lines longer will be reported. Default is 120.
# '\t' is counted as 1 character by default, and can be changed with the tab-width option
line-length: 120
# tab width in spaces. Default to 1.
tab-width: 1
unused:
# treat code as a program (not a library) and report unused exported identifiers; default is false.
# XXX: if you enable this setting, unused will report a lot of false-positives in text editors:
# if it's called for subdir of a project it can't find funcs usages. All text editor integrations
# with golangci-lint call it on a directory with the changed file.
check-exported: false
unparam:
# Inspect exported functions, default is false. Set to true if no external program/library imports your code.
# XXX: if you enable this setting, unparam will report a lot of false-positives in text editors:
# if it's called for subdir of a project it can't find external interfaces. All text editor integrations
# with golangci-lint call it on a directory with the changed file.
check-exported: false
nakedret:
# make an issue if func has more lines of code than this setting and it has naked returns; default is 30
max-func-lines: 30
prealloc:
# XXX: we don't recommend using this linter before doing performance profiling.
# For most programs usage of prealloc will be a premature optimization.
# Report preallocation suggestions only on simple loops that have no returns/breaks/continues/gotos in them.
# True by default.
simple: true
range-loops: true # Report preallocation suggestions on range loops, true by default
for-loops: false # Report preallocation suggestions on for loops, false by default
gocritic:
# Which checks should be enabled; can't be combined with 'disabled-checks';
# See https://go-critic.github.io/overview#checks-overview
# To check which checks are enabled run `GL_DEBUG=gocritic golangci-lint run`
# By default list of stable checks is used.
enabled-checks:
- rangeValCopy
# Which checks should be disabled; can't be combined with 'enabled-checks'; default is empty
disabled-checks:
- regexpMust
# Enable multiple checks by tags, run `GL_DEBUG=gocritic golangci-lint run` to see all tags and checks.
# Empty list by default. See https://github.com/go-critic/go-critic#usage -> section "Tags".
enabled-tags:
- performance
settings: # settings passed to gocritic
captLocal: # must be valid enabled check name
paramsOnly: true
rangeValCopy:
sizeThreshold: 32
godox:
# report any comments starting with keywords, this is useful for TODO or FIXME comments that
# might be left in the code accidentally and should be resolved before merging
keywords: # default keywords are TODO, BUG, and FIXME, these can be overwritten by this setting
- NOTE
- OPTIMIZE # marks code that should be optimized before merging
- HACK # marks hack-arounds that should be removed before merging
dogsled:
# checks assignments with too many blank identifiers; default is 2
max-blank-identifiers: 2
whitespace:
multi-if: false # Enforces newlines (or comments) after every multi-line if statement
multi-func: false # Enforces newlines (or comments) after every multi-line function signature
wsl:
# If true append is only allowed to be cuddled if appending value is
# matching variables, fields or types on line above. Default is true.
strict-append: true
# Allow calls and assignments to be cuddled as long as the lines have any
# matching variables, fields or types. Default is true.
allow-assign-and-call: true
# Allow multiline assignments to be cuddled. Default is true.
allow-multiline-assign: true
# Allow declarations (var) to be cuddled.
allow-cuddle-declarations: false
# Allow trailing comments in ending of blocks
allow-trailing-comment: false
# Force newlines in end of case at this limit (0 = never).
force-case-trailing-whitespace: 0
linters:
enable:
- megacheck
- govet
disable:
- maligned
- prealloc
disable-all: false
presets:
- bugs
- unused
fast: false
issues:
# List of regexps of issue texts to exclude, empty list by default.
# But independently from this option we use default exclude patterns,
# it can be disabled by `exclude-use-default: false`. To list all
# excluded by default patterns execute `golangci-lint run --help`
exclude:
- abcdef
# Excluding configuration per-path, per-linter, per-text and per-source
exclude-rules:
# Exclude some linters from running on tests files.
- path: _test\.go
linters:
- gocyclo
- errcheck
- dupl
- gosec
# Exclude known linters from partially hard-vendored code,
# which is impossible to exclude via "nolint" comments.
- path: internal/hmac/
text: "weak cryptographic primitive"
linters:
- gosec
# Exclude some staticcheck messages
- linters:
- staticcheck
text: "SA9003:"
# Exclude lll issues for long lines with go:generate
- linters:
- lll
source: "^//go:generate "
# Independently from option `exclude` we use default exclude patterns,
# it can be disabled by this option. To list all
# excluded by default patterns execute `golangci-lint run --help`.
# Default value for this option is true.
exclude-use-default: false
# Maximum issues count per one linter. Set to 0 to disable. Default is 50.
max-issues-per-linter: 0
# Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
max-same-issues: 0
# Show only new issues: if there are unstaged changes or untracked files,
# only those changes are analyzed, else only changes in HEAD~ are analyzed.
# It's a super-useful option for integration of golangci-lint into existing
# large codebase. It's not practical to fix all existing issues at the moment
# of integration: much better don't allow issues in new code.
# Default is false.
new: false
# Show only new issues created after git revision `REV`
new-from-rev: REV
# Show only new issues created in git patch with set file path.
new-from-patch: path/to/patch/file
It's a .golangci.yml config file of this repo: we enable more linters than the default and have more strict settings:
linters-settings:
govet:
check-shadowing: true
settings:
printf:
funcs:
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Infof
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Warnf
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Errorf
- (github.com/golangci/golangci-lint/pkg/logutils.Log).Fatalf
golint:
min-confidence: 0
gocyclo:
min-complexity: 15
maligned:
suggest-new: true
dupl:
threshold: 100
goconst:
min-len: 2
min-occurrences: 2
depguard:
list-type: blacklist
packages:
# logging is allowed only by logutils.Log, logrus
# is allowed to use only in logutils package
- github.com/sirupsen/logrus
packages-with-error-messages:
github.com/sirupsen/logrus: "logging is allowed only by logutils.Log"
misspell:
locale: US
lll:
line-length: 140
goimports:
local-prefixes: github.com/golangci/golangci-lint
gocritic:
enabled-tags:
- diagnostic
- experimental
- opinionated
- performance
- style
disabled-checks:
- wrapperFunc
- dupImport # https://github.com/go-critic/go-critic/issues/845
- ifElseChain
- octalLiteral
funlen:
lines: 100
statements: 50
linters:
# please, do not use `enable-all`: it's deprecated and will be removed soon.
# inverted configuration with `enable-all` and `disable` is not scalable during updates of golangci-lint
disable-all: true
enable:
- bodyclose
- deadcode
- depguard
- dogsled
- dupl
- errcheck
- funlen
- gochecknoinits
- goconst
- gocritic
- gocyclo
- gofmt
- goimports
- golint
- gosec
- gosimple
- govet
- ineffassign
- interfacer
- lll
- misspell
- nakedret
- scopelint
- staticcheck
- structcheck
- stylecheck
- typecheck
- unconvert
- unparam
- unused
- varcheck
- whitespace
# don't enable:
# - gochecknoglobals
# - gocognit
# - godox
# - maligned
# - prealloc
run:
skip-dirs:
- test/testdata_etc
skip-files:
- internal/cache/.*_test.go
issues:
exclude-rules:
- path: internal/(cache|renameio)/
linters:
- lll
- gochecknoinits
- gocyclo
- funlen
# golangci.com configuration
# https://github.com/golangci/golangci/wiki/Configuration
service:
golangci-lint-version: 1.20.x # use the fixed version to not introduce new linters unexpectedly
prepare:
- echo "here I can run custom commands, but no preparation needed for this repo"
False positives are inevitable, but we did our best to reduce their count. For example, we have a default enabled set of exclude patterns. If a false positive occurred you have the following choices:
- Exclude issue by text using command-line option
-e
or config optionissues.exclude
. It's helpful when you decided to ignore all issues of this type. Also, you can useissues.exclude-rules
config option for per-path or per-linter configuration. - Exclude this one issue by using special comment
//nolint
(see the section below). - Exclude issues in path by
run.skip-dirs
,run.skip-files
orissues.exclude-rules
config options.
Please create GitHub Issues here if you find any false positives. We will add it to the default exclude list if it's common or we will fix underlying linter.
To exclude issues from all linters use //nolint
. For example, if it's used inline (not from the beginning of the line) it excludes issues only for this line.
var bad_name int //nolint
To exclude issues from specific linters only:
var bad_name int //nolint:golint,unused
To exclude issues for the block of code use this directive on the beginning of a line:
//nolint
func allIssuesInThisFunctionAreExcluded() *string {
// ...
}
//nolint:govet
var (
a int
b int
)
Also, you can exclude all issues in a file by:
//nolint:unparam
package pkg
You may add a comment explaining or justifying why //nolint
is being used on the same line as the flag itself:
//nolint:gocyclo // This legacy function is complex but the team too busy to simplify it
func someLegacyFunction() *string {
// ...
}
You can see more examples of using //nolint
in our tests for it.
Use //nolint
instead of // nolint
because machine-readable comments should have no space by Go convention.
How do you add a custom linter?
You can integrate it yourself, see this wiki page with documentation. Or you can create a GitHub Issue and we will integrate when time permits.
It's cool to use golangci-lint
when starting a project, but what about existing projects with large codebase? It will take days to fix all found issues
We are sure that every project can easily integrate golangci-lint
, even the large one. The idea is to not fix all existing issues. Fix only newly added issue: issues in new code. To do this setup CI (or better use GolangCI) to run golangci-lint
with option --new-from-rev=HEAD~1
. Also, take a look at option --new
, but consider that CI scripts that generate unstaged files will make --new
only point out issues in those files and not in the last commit. In that regard --new-from-rev=HEAD~1
is safer.
By doing this you won't create new issues in your code and can choose fix existing issues (or not).
How to use golangci-lint
in CI (Continuous Integration)?
You have 2 choices:
- Use GolangCI: this service is highly integrated with GitHub (issues are commented in the pull request) and uses a
golangci-lint
tool. For configuration use.golangci.yml
(or toml/json). - Use custom CI: just run
golangci-lint
in CI and check the exit code. If it's non-zero - fail the build. The main disadvantage is that you can't see issues in pull request code and would need to view the build log, then open the referenced source file to see the context.
We don't recommend vendoring golangci-lint
in your repo: you will get troubles updating golangci-lint
. Please, use recommended way to install with the shell script: it's very fast.
Do I need to run go install
?
No, you don't need to do it anymore.
Which go versions are supported Short answer: go 1.12 and newer are officially supported.
Long answer:
- go < 1.9 isn't supported
- go1.9 is officially supported by golangci-lint <= v1.10.2
- go1.10 is officially supported by golangci-lint <= 1.15.0.
- go1.11 is officially supported by golangci-lint <= 1.17.1.
- go1.12+ are officially supported by the latest version of golangci-lint (>= 1.18.0).
golangci-lint
doesn't work
- Please, ensure you are using the latest binary release.
- Run it with
-v
option and check the output. - If it doesn't help create a GitHub issue with the output from the error and #2 above.
Why running with --fast
is slow on the first run?
Because the first run caches type information. All subsequent runs will be fast.
Usually this options is used during development on local machine and compilation was already performed.
Thanks to all contributors! Thanks to alecthomas/gometalinter for inspiration and amazing work. Thanks to bradleyfalzon/revgrep for cool diff tool.
Thanks to developers and authors of used linters:
- timakin
- kisielk
- golang
- dominikh
- securego
- opennota
- mvdan
- mdempsky
- gordonklaus
- mibk
- jgautheron
- remyoudompheng
- alecthomas
- uudashr
- OpenPeeDeeP
- client9
- walle
- alexkohler
- kyoh86
- go-critic
- leighmcculloch
- matoous
- ultraware
- bombsimon
- tommy-muehle
Follow the news and releases on our twitter and our blog. There is the most valuable changes log:
- Support go1.13
- Add new linters:
funlen
,whitespace
(with auto-fix) andgodox
- Update linters:
gochecknoglobals
,scopelint
,gosec
- Provide pre-built binary for ARM and FreeBSD
-
- Fix false-positives in
unused
- Fix false-positives in
- Support
--skip-dirs-use-default
- Add support for bash completions
- Fix parallel writes race condition
- Update bodyclose with fixed panic
- Treat Go source files as a plain text by
misspell
: it allows detecting issues in strings, variable names, etc. - Implement richer and more stable auto-fix of
misspell
issues.
- Add bodyclose linter.
- Support junit-xml output.
- Update go-critic, new checkers were added: badCall, dupImports, evalOrder, newDeref
- Fix staticcheck panic on packages that do not compile
- Make install script work on Windows
- Fix compatibility with the latest x/tools version and update golang.org/x/tools
- Correct import path of module sourcegraph/go-diff
- Fix
max-issues-per-linter
name - Fix linting of preprocessed files (e.g.
*.qtpl.go
, goyacc) - Enable auto-fixing when running via pre-commit
- Support the newest
go vet
(withgo/analysis
) - Support configuration of
go vet
: e.g. you can set print functions bylinters-settings.govet.settings.printf.funcs
- Update megacheck (staticcheck) to 2019.1.1
- Add information about controlling space-time trade-off into README
- Exclude issues by source code line regexp by
issues.exclude-rules[i].source
- Build and test on go 1.12
- Support
--color
option - Update x/tools to fix c++ issues
- Include support for log level
- Sort linters list in help commands
You can see a verbose output of linter by using -v
option.
If you would like to see more detailed logs you can set environment variable GL_DEBUG
to debug golangci-lint
.
It's value is a list of debug tags. For example, GL_DEBUG=loader,gocritic golangci-lint run
.
Existing debug tags:
gocritic
- debuggo-critic
linter;env
- debuggo env
command;loader
- debug packages loading (includinggo/packages
internal debugging);autogen_exclude
- debug a filter excluding autogenerated source code;nolint
- debug a filter excluding issues by//nolint
comments.
- Upstream all changes of forked linters.
- Make it easy to write own linter/checker: it should take a minimum code, have perfect documentation, debugging and testing tooling.
- Speed up SSA loading: on-disk cache and existing code profiling-optimizing.
- Analyze (don't only filter) only new code: analyze only changed files and dependencies, make incremental analysis, caches.
- Smart new issues detector: don't print existing issues on changed lines.
- Minimize false-positives by fixing linters and improving testing tooling.
- Automatic issues fixing (code rewrite, refactoring) where it's possible.
- Documentation for every issue type.
You can contact the author of GolangCI-Lint by [email protected]. Follow the news and releases on our twitter and our blog.