Golang pre-commit搭配golangci-lint hook做linting檢查

在Go專案利用pre-commit搭配golangci-lint做git commit前的linting檢查。

pre-commit除了本身pre-commit-hooks的hooks檢查外也可加入外部的hooks檢查，通常會搭配linter提供的hook做程式碼linting。支援的外部hooks可參考Supported hooks。

參考「使用pre-commit做commit前檢查」及「Go golangci-lint安裝及使用」了解並安裝好pre-commit及golangci-lint。

範例

pre-commit加入golangci-lint的hooks如下，在pre-commit配置檔.pre-commit-config.yaml加入golangci-lint hook的repo及id即可，repo為golangci-lint的github位址https://github.com/golangci/golangci-lint，rev為Tags的版本。

.pre-commit-config.yaml

repos:
-   repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v2.3.0
    hooks:
    -   id: check-yaml
    -   id: end-of-file-fixer
    -   id: trailing-whitespace
-   repo: https://github.com/golangci/golangci-lint # golangci-lint hook repo
    rev: v1.42.0 # golangci-lint hook repo revision
    hooks:
    -   id: golangci-lint # hook id

設定好配置檔後在Go專案根目錄輸入pre-commit install載入剛加入的golangci-lint hook到專案的.git/hooks。

~/.../go-demo$ pre-commit install
pre-commit installed at .git/hooks/pre-commit

到此便完成pre-commit加入golangci-lint hook設定，之後提交的go程式就會多了golangci-lint的檢查。

例如在main.go加一未使用的package變數g。

main.go

package main

import "fmt"

var g = 123

func main() {
    fmt.Println("Hello World")
}

git commit此異動時會做pre-commit檢查，其中包括了golangci-lint

~/.../go-demo$ git commit -m "test"
[INFO] Initializing environment for https://github.com/golangci/golangci-lint.
[INFO] Installing environment for https://github.com/golangci/golangci-lint.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
Check Yaml...........................................(no files to check)Skipped
Fix End of Files.........................................................Passed
Trim Trailing Whitespace.................................................Passed
golangci-lint............................................................Failed
- hook id: golangci-lint
- exit code: 1

main.go:5:5: `g` is unused (deadcode)
var g = 123
    ^

參考github。

但通常除了golangci-lint hook還會加入其他外部hooks，有許多已整合多個外部hooks的repo可使用，例如github.com/dnephin/pre-commit-golang及整合了golangci-lint hook。