Add linter (#34)

* Add linter
* Setup linters + some fixes

Author: BoRuDar

.github/workflows/linter.yml

@@ -0,0 +1,30 @@
+name: "Linter"
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.21'
+          cache: false
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v4
+        with:
+          version: v1.56.2
+          install-mode: "goinstall"
+          only-new-issues: false
+          skip-cache: true

.golangci.yml

@@ -0,0 +1,127 @@
+run:
+  timeout: 1m
+  tests: true
+  go: '1.18'
+  show-stats: true
+
+linters:
+  enable-all: true
+  # Disable specific linter
+  # https://golangci-lint.run/usage/linters/#disabled-by-default
+  disable:
+#    - asasalint
+#    - asciicheck
+#    - bidichk
+#    - bodyclose
+#    - containedctx
+#    - contextcheck
+#    - copyloopvar
+#    - cyclop
+    - deadcode
+#    - decorder
+#    - depguard
+#    - dogsled
+#    - dupl
+#    - dupword
+#    - durationcheck
+#    - errcheck
+#    - errchkjson
+#    - errname
+#    - errorlint
+#    - execinquery
+#    - exhaustive
+    - exhaustivestruct
+    - exhaustruct
+#    - exportloopref
+#    - forbidigo
+#    - forcetypeassert
+    - funlen
+#    - gci
+#    - ginkgolinter
+#    - gocheckcompilerdirectives
+#    - gochecknoglobals
+#    - gochecknoinits
+#    - gochecksumtype
+#    - gocognit
+#    - goconst
+#    - gocritic
+#    - gocyclo
+    - godot
+#    - godox
+    - goerr113
+#    - gofmt
+#    - gofumpt
+#    - goheader
+#    - goimports
+    - golint
+#    - gomnd
+#    - gomoddirectives
+#    - gomodguard
+#    - goprintffuncname
+#    - gosec
+#    - gosimple
+#    - gosmopolitan
+#    - govet
+#    - grouper
+    - ifshort
+#    - importas
+#    - inamedparam
+#    - ineffassign
+#    - interfacebloat
+    - interfacer
+#    - intrange
+#    - ireturn
+    - lll
+#    - loggercheck
+#    - maintidx
+#    - makezero
+    - maligned
+#    - mirror
+#    - misspell
+#    - musttag
+#    - nakedret
+#    - nestif
+#    - nilerr
+#    - nilnil
+    - nlreturn
+#    - noctx
+    - nolintlint
+    - nonamedreturns
+    - nosnakecase
+#    - nosprintfhostport
+#    - paralleltest
+    - perfsprint
+#    - prealloc
+#    - predeclared
+#    - promlinter
+#    - protogetter
+#    - reassign
+#    - revive
+#    - rowserrcheck
+    - scopelint
+#    - sloglint
+#    - spancheck
+#    - sqlclosecheck
+#    - staticcheck
+    - structcheck
+#    - stylecheck
+    - tagalign
+#    - tagliatelle
+#    - tenv
+#    - testableexamples
+#    - testifylint
+    - testpackage
+#    - thelper
+#    - tparallel
+#    - typecheck
+#    - unconvert
+    - unparam
+#    - unused
+#    - usestdlibvars
+    - varcheck
+    - varnamelen
+#    - wastedassign
+#    - whitespace
+#    - wrapcheck
+    - wsl
+#    - zerologlint

Makefile

@@ -1,7 +1,16 @@
 COVERAGE_FILE="coverage.out"
 
+.PHONY: test
 test:
 	go test -v -cover -coverprofile=$(COVERAGE_FILE) -covermode=atomic -count 1  ./...
 
+.PHONY: coverage
 coverage: test
 	go tool cover -html=$(COVERAGE_FILE)
+
+.PHONY: tools
+tools:
+	go install github.com/golangci/golangci-lint/cmd/[email protected]
+
+linter:
+	golangci-lint run ./...

configurator.go

@@ -60,7 +60,7 @@ func (c *Configurator) InitValues() error {
 		c.registeredTags[p.Name()] = struct{}{}
 
 		if err := p.Init(c.configPtr); err != nil {
-			return fmt.Errorf("cannot init [%s] provider: %v", p.Name(), err)
+			return fmt.Errorf("cannot init [%s] provider: %w", p.Name(), err)
 		}
 	}
 
@@ -112,7 +112,7 @@ func (c *Configurator) applyProviders(field reflect.StructField, v reflect.Value
 		}
 	}
 
-	c.onErrorFn(fmt.Errorf("configurator: field [%s] with tags [%v] cannot be set. Last Provider error: %s", field.Name, field.Tag, lastErr))
+	c.onErrorFn(fmt.Errorf("configurator: field [%s] with tags [%v] cannot be set. Last Provider error: %w", field.Name, field.Tag, lastErr))
 }
 
 // FromEnvAndDefault is a shortcut for `New(cfg, NewEnvProvider(), NewDefaultProvider()).InitValues()`.

configurator_test.go

@@ -31,14 +31,14 @@ func TestConfigurator(t *testing.T) {
 		ObjPtr   *struct {
 			F32       float32       `default:"32"`
 			StrPtr    *string       `default:"str_ptr_test"`
-			HundredMS time.Duration `default:"100ms"`
+			HundredMS time.Duration `default:"100ms"` // nolint:stylecheck
 		}
 		Obj struct {
 			IntPtr     *int16   `default:"123"`
 			Beta       int      `file_json:"inside.beta"   default:"24"`
 			StrSlice   []string `default:"one;two"`
 			IntSlice   []int64  `default:"3; 4"`
-			unexported string   `xml:"ignored"`
+			unexported string   `xml:"ignored"` // nolint:govet
 		}
 		URLs   []*string `default:"http://localhost:3000;1.2.3.4:8080"`
 		HostIP ipTest    `default:"127.0.0.3"`

defaultProvider.go

@@ -8,6 +8,7 @@ import (
 const DefaultProviderName = `DefaultProvider`
 
 // NewDefaultProvider creates new provider which sets values from `default` tag
+// nolint:revive
 func NewDefaultProvider() defaultProvider {
 	return defaultProvider{}
 }

defaultProvider_test.go

@@ -1,3 +1,4 @@
+// nolint:dupl
 package configuration
 
 import (

envProvider.go

@@ -10,6 +10,7 @@ import (
 const EnvProviderName = `EnvProvider`
 
 // NewEnvProvider creates provider which sets values from ENV variables (gets variable name from `env` tag)
+// nolint:revive
 func NewEnvProvider() envProvider {
 	return envProvider{}
 }

envProvider_test.go

@@ -1,3 +1,4 @@
+// nolint:dupl
 package configuration
 
 import (

fieldSetter.go

@@ -10,6 +10,7 @@ import (
 
 const sliceSeparator = ";"
 
+// FieldSetter interface
 type FieldSetter interface {
 	SetField(field reflect.StructField, val reflect.Value, valStr string) error
 }
@@ -33,7 +34,9 @@ func SetField(field reflect.StructField, val reflect.Value, valStr string) error
 	return setValue(field.Type, val, valStr)
 }
 
-func setValue(t reflect.Type, v reflect.Value, val string) (err error) {
+func setValue(t reflect.Type, v reflect.Value, val string) error {
+	var err error
+
 	switch t.Kind() {
 	case reflect.String:
 		v.SetString(val)
@@ -63,7 +66,8 @@ func setValue(t reflect.Type, v reflect.Value, val string) (err error) {
 	default:
 		err = fmt.Errorf("setValue: unsupported type: %v", v.Kind().String())
 	}
-	return
+
+	return err
 }
 
 func setInt64(v reflect.Value, val string) {
@@ -79,6 +83,7 @@ func setInt64(v reflect.Value, val string) {
 	v.SetInt(i)
 }
 
+// nolint:cyclop
 func setSlice(t reflect.Type, v reflect.Value, val string) error {
 	var (
 		slice reflect.Value
@@ -141,7 +146,10 @@ func setSlice(t reflect.Type, v reflect.Value, val string) error {
 	return nil
 }
 
-func setPtrValue(t reflect.Type, v reflect.Value, val string) (err error) {
+// nolint:cyclop
+func setPtrValue(t reflect.Type, v reflect.Value, val string) error {
+	var err error
+
 	switch t.Elem().Name() {
 	case reflect.Int.String():
 		if i, err := strconv.Atoi(val); err == nil {
@@ -214,7 +222,8 @@ func setPtrValue(t reflect.Type, v reflect.Value, val string) (err error) {
 	default:
 		err = fmt.Errorf("setPtrValue: unsupported type: %v", t.Kind().String())
 	}
-	return
+
+	return err
 }
 
 func splitIntoSlice(val string) []string {