chore: lint code with golangci-lint (#1828)

* feat: add golangci-lint linting

* chore: fix linter issues

* feat: add linting into the workflow

* docs: update lint docs

* fix: cr suggestions

* fix: remove old formatting and vetting scripts

* fix: add docker make target

* fix: action go caching

* fix: depreciated actions checkout version

* fix: cr suggestion

* fix: cr suggestions

---------

Co-authored-by: Manu Gupta <manugupt1@gmail.com>

pkg/download/get_module_params.go

@@ -7,7 +7,7 @@ import (
 	"github.com/gomods/athens/pkg/paths"
 )
 
-func getModuleParams(r *http.Request, op errors.Op) (mod string, ver string, err error) {
+func getModuleParams(r *http.Request, op errors.Op) (mod, ver string, err error) {
 	params, err := paths.GetAllParams(r)
 	if err != nil {
 		return "", "", errors.E(op, err, errors.KindBadRequest)

pkg/download/handler.go

@@ -15,8 +15,7 @@ import (
 // a ready-to-go http handler that serves up cmd/go's download protocol.
 type ProtocolHandler func(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handler
 
-// HandlerOpts are the generic options
-// for a ProtocolHandler
+// HandlerOpts are the generic options for a ProtocolHandler.
 type HandlerOpts struct {
 	Protocol     Protocol
 	Logger       *log.Logger
@@ -26,7 +25,7 @@ type HandlerOpts struct {
 // LogEntryHandler pulls a log entry from the request context. Thanks to the
 // LogEntryMiddleware, we should have a log entry stored in the context for each
 // request with request-specific fields. This will grab the entry and pass it to
-// the protocol handlers
+// the protocol handlers.
 func LogEntryHandler(ph ProtocolHandler, opts *HandlerOpts) http.Handler {
 	f := func(w http.ResponseWriter, r *http.Request) {
 		ent := log.EntryFromContext(r.Context())

pkg/download/latest.go

@@ -13,7 +13,7 @@ import (
 // PathLatest URL.
 const PathLatest = "/{module:.+}/@latest"
 
-// LatestHandler implements GET baseURL/module/@latest
+// LatestHandler implements GET baseURL/module/@latest.
 func LatestHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handler {
 	const op errors.Op = "download.LatestHandler"
 	f := func(w http.ResponseWriter, r *http.Request) {

pkg/download/list.go

@@ -14,7 +14,7 @@ import (
 // PathList URL.
 const PathList = "/{module:.+}/@v/list"
 
-// ListHandler implements GET baseURL/module/@v/list
+// ListHandler implements GET baseURL/module/@v/list.
 func ListHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handler {
 	const op errors.Op = "download.ListHandler"
 	f := func(w http.ResponseWriter, r *http.Request) {

pkg/download/mode/mode.go

@@ -4,6 +4,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/gomods/athens/pkg/errors"
@@ -16,7 +17,7 @@ import (
 // when a module is not found in storage.
 type Mode string
 
-// DownloadMode constants. For more information see config.dev.toml
+// DownloadMode constants. For more information see config.dev.toml.
 const (
 	Sync            Mode = "sync"
 	Async           Mode = "async"
@@ -59,7 +60,7 @@ func NewFile(m Mode, downloadURL string) (*DownloadFile, error) {
 
 	if strings.HasPrefix(string(m), "file:") {
 		filePath := string(m[5:])
-		bts, err := os.ReadFile(filePath)
+		bts, err := os.ReadFile(filepath.Clean(filePath))
 		if err != nil {
 			return nil, err
 		}

pkg/download/protocol.go

@@ -48,7 +48,7 @@ type Opts struct {
 	NetworkMode  string
 }
 
-// NetworkMode constants
+// NetworkMode constants.
 const (
 	Strict   = "strict"
 	Offline  = "offline"
@@ -263,12 +263,12 @@ func (p *protocol) processDownload(ctx context.Context, mod, ver string, f func(
 		}
 		return f(newVer)
 	case mode.Async:
-		go p.stasher.Stash(ctx, mod, ver)
+		go func() { _, _ = p.stasher.Stash(ctx, mod, ver) }()
 		return errors.E(op, "async: module not found", errors.KindNotFound)
 	case mode.Redirect:
 		return errors.E(op, "redirect", errors.KindRedirect)
 	case mode.AsyncRedirect:
-		go p.stasher.Stash(ctx, mod, ver)
+		go func() { _, _ = p.stasher.Stash(ctx, mod, ver) }()
 		return errors.E(op, "async_redirect: module not found", errors.KindRedirect)
 	case mode.None:
 		return errors.E(op, "none", errors.KindNotFound)
@@ -276,7 +276,7 @@ func (p *protocol) processDownload(ctx context.Context, mod, ver string, f func(
 	return nil
 }
 
-// union concatenates two version lists and removes duplicates
+// union concatenates two version lists and removes duplicates.
 func union(list1, list2 []string) []string {
 	if list1 == nil {
 		list1 = []string{}
@@ -284,10 +284,10 @@ func union(list1, list2 []string) []string {
 	if list2 == nil {
 		list2 = []string{}
 	}
-	list := append(list1, list2...)
+	list1 = append(list1, list2...)
 	unique := []string{}
 	m := make(map[string]struct{})
-	for _, v := range list {
+	for _, v := range list1 {
 		if _, ok := m[v]; !ok {
 			unique = append(unique, v)
 			m[v] = struct{}{}

pkg/download/version_info.go

@@ -11,7 +11,7 @@ import (
 // PathVersionInfo URL.
 const PathVersionInfo = "/{module:.+}/@v/{version}.info"
 
-// InfoHandler implements GET baseURL/module/@v/version.info
+// InfoHandler implements GET baseURL/module/@v/version.info.
 func InfoHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handler {
 	const op errors.Op = "download.InfoHandler"
 	f := func(w http.ResponseWriter, r *http.Request) {
@@ -38,7 +38,7 @@ func InfoHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handle
 			w.WriteHeader(errors.Kind(err))
 		}
 
-		w.Write(info)
+		_, _ = w.Write(info)
 	}
 	return http.HandlerFunc(f)
 }

pkg/download/version_module.go

@@ -11,7 +11,7 @@ import (
 // PathVersionModule URL.
 const PathVersionModule = "/{module:.+}/@v/{version}.mod"
 
-// ModuleHandler implements GET baseURL/module/@v/version.mod
+// ModuleHandler implements GET baseURL/module/@v/version.mod.
 func ModuleHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handler {
 	const op errors.Op = "download.VersionModuleHandler"
 	f := func(w http.ResponseWriter, r *http.Request) {
@@ -42,7 +42,7 @@ func ModuleHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Hand
 			return
 		}
 
-		w.Write(modBts)
+		_, _ = w.Write(modBts)
 	}
 	return http.HandlerFunc(f)
 }

pkg/download/version_zip.go

@@ -13,7 +13,7 @@ import (
 // PathVersionZip URL.
 const PathVersionZip = "/{module:.+}/@v/{version}.zip"
 
-// ZipHandler implements GET baseURL/module/@v/version.zip
+// ZipHandler implements GET baseURL/module/@v/version.zip.
 func ZipHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handler {
 	const op errors.Op = "download.ZipHandler"
 	f := func(w http.ResponseWriter, r *http.Request) {
@@ -41,7 +41,7 @@ func ZipHandler(dp Protocol, lggr log.Entry, df *mode.DownloadFile) http.Handler
 			w.WriteHeader(errors.Kind(err))
 			return
 		}
-		defer zip.Close()
+		defer func() { _ = zip.Close() }()
 
 		w.Header().Set("Content-Type", "application/zip")
 		size := zip.Size()