add lint

.drone.yml

@@ -0,0 +1,42 @@
+kind: pipeline
+name: default
+
+steps:
+- name: golangci-lint
+  image: golangci/golangci-lint:v1.49
+  volumes:
+    - name: deps
+      path: /go/src/mod
+  commands:
+  - golangci-lint run --timeout 5m
+
+- name: test 
+  image: golang
+  volumes:
+  - name: deps
+    path: /go/src/mod
+  commands:
+  - go test ./...
+
+- name: example golangci-lint
+  image: golangci/golangci-lint:v1.49
+  volumes:
+    - name: deps
+      path: /go/src/mod
+  commands:
+  - cd scripts
+  - golangci-lint run --timeout 5m
+
+- name: example test
+  image: golang
+  volumes:
+  - name: deps
+    path: /go/src/mod
+  commands:
+  - cd scripts
+  - go test ./...
+
+volumes:
+- name: deps
+  temp: {}
+

.golangci.yml

@@ -0,0 +1,43 @@
+linters-settings:
+    dupl:
+      threshold: 100
+    funlen:
+      lines: 100
+      statements: 50
+    goconst:
+      min-len: 2
+      min-occurrences: 2
+    gocyclo:
+      min-complexity: 15
+    golint:
+      min-confidence: 0
+    govet:
+      check-shadowing: true
+    lll:
+      line-length: 140
+    maligned:
+      suggest-new: true
+    misspell:
+      locale: US  
+    varnamelen:
+      min-name-length: 2
+
+linters:
+    enable-all: true
+    disable:
+      - varcheck
+      - maligned
+      - scopelint
+      - nosnakecase
+      - ifshort
+      - golint
+      - interfacer
+      - structcheck
+      - deadcode
+      - exhaustivestruct
+      - exhaustruct
+
+# is disabled because of generics. You can track the evolution of the generics support by following the https://github.com/golangci/golangci-lint/issues/2649
+      - rowserrcheck
+      - sqlclosecheck
+      - wastedassign

mime.go

@@ -13,6 +13,7 @@ func (v Mime) Is(types ...Mime) bool {
 			return true
 		}
 	}
+
 	return false
 }
 

scripts/main.go

@@ -11,8 +11,10 @@ import (
 
 func main() {
 	ctx, cancel := context.WithCancel(context.Background())
+
 	closer.AddLast(func() error {
 		cancel()
+
 		return nil
 	})
 

scripts/mime/generate.go

@@ -1,9 +1,9 @@
 package mime
 
 import (
+	"errors"
 	"fmt"
 	"go/format"
-	"io/ioutil"
 	"os"
 	"path"
 	"text/template"
@@ -11,6 +11,16 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+var (
+	ErrDuplicate = errors.New("duplicate")
+	ErrNotFound  = errors.New("not found")
+)
+
+const (
+	NameExt  = "ext"
+	NameMime = "mime"
+)
+
 type Config struct {
 	Source string
 
@@ -33,6 +43,28 @@ type Data struct {
 	Value []string `yaml:"value,omitempty"`
 }
 
+func (c *Config) Base(name string) string {
+	switch name {
+	case NameExt:
+		return path.Base(c.ExtTpl)
+	case NameMime:
+		return path.Base(c.MimeTpl)
+	}
+
+	return ""
+}
+
+func (c *Config) Result(name string) string {
+	switch name {
+	case NameExt:
+		return c.ExtResult
+	case NameMime:
+		return c.MimeResult
+	}
+
+	return ""
+}
+
 func (c *Config) ValidateAndFillExt() error {
 	mimes := make(map[string]int)
 	mimeIDs := make(map[int]string)
@@ -40,7 +72,7 @@ func (c *Config) ValidateAndFillExt() error {
 
 	for idx, ext := range c.Extensions {
 		if _, ok := extIndex[ext.Name]; ok {
-			return fmt.Errorf("extension %v duplicate: with id %v", ext.Name, c.Extensions[extIndex[ext.Name]].ID)
+			return fmt.Errorf("extension %v %w: with id %v", ext.Name, ErrDuplicate, c.Extensions[extIndex[ext.Name]].ID)
 		}
 
 		extIndex[ext.Name] = idx
@@ -48,22 +80,21 @@ func (c *Config) ValidateAndFillExt() error {
 
 	for _, mime := range c.Mimes {
 		if _, ok := mimes[mime.Name]; ok {
-			return fmt.Errorf("mime %v duplicate: with id %v", mime.Name, mimes[mime.Name])
+			return fmt.Errorf("mime %v %w: with id %v", mime.Name, ErrDuplicate, mimes[mime.Name])
 		}
 
 		if _, ok := mimeIDs[mime.ID]; ok {
-			return fmt.Errorf("ID %v duplicate: with name %v", mime.ID, mimeIDs[mime.ID])
+			return fmt.Errorf("ID %v %w: with name %v", mime.ID, ErrDuplicate, mimeIDs[mime.ID])
 		}
 
 		for _, ext := range mime.Value {
 			idx, ok := extIndex[ext]
 			if !ok {
-				return fmt.Errorf("not fount ext by %v", mime.Name)
+				return fmt.Errorf("%w ext by %v", ErrNotFound, mime.Name)
 			}
 
 			c.Extensions[idx].Value = append(c.Extensions[idx].Value, mime.Name)
 		}
-
 	}
 
 	return nil
@@ -133,17 +164,17 @@ func Generate(fileName string, opts ...Option) error {
 		opt(&cfg)
 	}
 
-	data, err := os.ReadFile(fileName)
+	data, cerr := os.ReadFile(fileName)
-	if err != nil {
+	if cerr != nil {
-		return fmt.Errorf("read file:%w", err)
+		return fmt.Errorf("read file:%w", cerr)
 	}
 
-	if err := yaml.Unmarshal(data, &cfg); err != nil {
+	if uerr := yaml.Unmarshal(data, &cfg); uerr != nil {
-		return fmt.Errorf("unmarshal:%w", err)
+		return fmt.Errorf("unmarshal:%w", uerr)
 	}
 
-	if err := cfg.ValidateAndFillExt(); err != nil {
+	if validErr := cfg.ValidateAndFillExt(); validErr != nil {
-		return fmt.Errorf("config:%w", err)
+		return fmt.Errorf("config:%w", validErr)
 	}
 
 	template, err := template.New("mimes").Funcs(funcMap()).ParseFiles(cfg.ExtTpl, cfg.MimeTpl)
@@ -151,30 +182,29 @@ func Generate(fileName string, opts ...Option) error {
 		return fmt.Errorf("ext template:%w", err)
 	}
 
-	extFile, err := os.Create(cfg.ExtResult)
+	if exErr := Create(template, NameExt, cfg); exErr != nil {
+		return fmt.Errorf("ext create:%w", exErr)
+	}
+
+	if mimeErr := Create(template, NameMime, cfg); mimeErr != nil {
+		return fmt.Errorf("mime create:%w", mimeErr)
+	}
+
+	return nil
+}
+
+func Create(tpl *template.Template, name string, cfg Config) error {
+	extFile, err := os.Create(cfg.Result(name))
 	if err != nil {
 		return fmt.Errorf("ext file:%w", err)
 	}
 
-	if err := template.ExecuteTemplate(extFile, path.Base(cfg.ExtTpl), cfg); err != nil {
+	if exErr := tpl.ExecuteTemplate(extFile, cfg.Base(name), cfg); exErr != nil {
-		return fmt.Errorf("ext execute:%w", err)
+		return fmt.Errorf("ext execute:%w", exErr)
 	}
 
-	if err := Format(extFile.Name()); err != nil {
+	if formatErr := Format(extFile.Name()); formatErr != nil {
-		return fmt.Errorf("format ext:%w", err)
+		return fmt.Errorf("format ext:%w", formatErr)
-	}
-
-	mimeFile, err := os.Create(cfg.MimeResult)
-	if err != nil {
-		return fmt.Errorf("mime file:%w", err)
-	}
-
-	if err := template.ExecuteTemplate(mimeFile, path.Base(cfg.MimeTpl), cfg); err != nil {
-		return fmt.Errorf("mime execute:%w", err)
-	}
-
-	if err := Format(mimeFile.Name()); err != nil {
-		return fmt.Errorf("format mime:%w", err)
 	}
 
 	return nil
@@ -182,13 +212,14 @@ func Generate(fileName string, opts ...Option) error {
 
 // Format file and write it.
 func Format(name string) error {
-	in, err := ioutil.ReadFile(name)
+	in, err := os.ReadFile(name)
 	if err != nil {
-		return err
+		return fmt.Errorf("read file:%w", err)
 	}
+
 	out, err := format.Source(in)
 	if err != nil {
-		return err
+		return fmt.Errorf("format source:%w", err)
 	}
 
 	file, err := os.Create(name)
@@ -202,19 +233,3 @@ func Format(name string) error {
 
 	return nil
 }
-
-func extensions(mimes map[string][]string) map[string][]string {
-	out := make(map[string][]string)
-
-	for mime, exts := range mimes {
-		for _, ext := range exts {
-			if _, ok := out[ext]; ok {
-				out[ext] = append(out[ext], mime)
-				continue
-			}
-			out[ext] = []string{mime}
-		}
-	}
-
-	return out
-}