fix lint warnings (issue 2541) (#2551)

* Lint: fix some errcheck #2541

* Lint: fix passing structcheck #2541

* Lint: update fix structcheck #2541

* Lint: fix errcheck for basicauth, browse, fastcgi_test #2541

* Lint: fix errcheck for browse, fastcgi_test, fcgiclient, fcgiclient_test #2541

* Lint: fix errcheck for responsefilter_test, fcgilient_test #2541

* Lint: fix errcheck for header_test #2541

* Lint: update errcheck for fcgiclient_test #2541

* Lint: fix errcheck for server, header_test, fastcgi_test, https_test, recorder_test #2541

* Lint: fix errcheck for tplcontext, vhosttrie_test, internal_test, handler_test #2541

* Lint: fix errcheck for log_test, markdown mholt#2541

* Lint: fix errcheck for policy, body_test, proxy_test #2541

* Lint: fix errcheck for on multiple packages #2541

- reverseproxy
- reverseproxy_test
- upstream
- upstream_test
- body_test

* Lint: fix errcheck in multiple packages mholt#2541
- handler_test
- redirect_test
- requestid_test
- rewrite_test
- fileserver_test

* Lint: fix errcheck in multiple packages mholt#2541

- websocket
- setup
- collection
- redirect_test
- templates_test

* Lint: fix errcheck in logger test #2541

run goimports against #2551
- lexer_test
- log_test
- markdown

* Update caddyhttp/httpserver/logger_test.go

Co-Authored-By: Inconnu08 <taufiqrx8@gmail.com>

* Update log_test.go

* Lint: fix scope in logger_test #2541

* remove redundant err check in logger_test #2541

* fix alias in logger_test #2541

* fix import for format #2541

* refactor variable names and error check #2541

caddy_test.go

@@ -16,6 +16,7 @@ package caddy
 
 import (
 	"fmt"
+	"log"
 	"reflect"
 	"sync"
 	"testing"
@@ -103,13 +104,20 @@ func TestCaddyRestartCallbacks(t *testing.T) {
 			return nil
 		})
 
-		c.instance.Restart(CaddyfileInput{Contents: []byte(""), ServerTypeName: serverName})
+		_, err := c.instance.Restart(CaddyfileInput{Contents: []byte(""), ServerTypeName: serverName})
+		if err != nil {
+			log.Printf("[ERROR] Restart failed: %v", err)
+		}
 
 		if !reflect.DeepEqual(calls, test.expectedCalls) {
 			t.Errorf("Test %d: Callbacks expected: %v, got: %v", i, test.expectedCalls, calls)
 		}
 
-		c.instance.Stop()
+		err = c.instance.Stop()
+		if err != nil {
+			log.Printf("[ERROR] Stop failed: %v", err)
+		}
+
 		c.instance.Wait()
 	}
 

caddyfile/lexer_test.go

@@ -15,6 +15,7 @@
 package caddyfile
 
 import (
+	"log"
 	"strings"
 	"testing"
 )
@@ -158,7 +159,9 @@ func TestLexer(t *testing.T) {
 
 func tokenize(input string) (tokens []Token) {
 	l := lexer{}
-	l.load(strings.NewReader(input))
+	if err := l.load(strings.NewReader(input)); err != nil {
+		log.Printf("[ERROR] load failed: %v", err)
+	}
 	for l.next() {
 		tokens = append(tokens, l.token)
 	}

caddyhttp/basicauth/basicauth.go

@@ -26,6 +26,7 @@ import (
 	"crypto/subtle"
 	"fmt"
 	"io"
+	"log"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -193,11 +194,15 @@ func PlainMatcher(passw string) PasswordMatcher {
 	// compare hashes of equal length instead of actual password
 	// to avoid leaking password length
 	passwHash := sha1.New()
-	passwHash.Write([]byte(passw))
+	if _, err := passwHash.Write([]byte(passw)); err != nil {
+		log.Printf("[ERROR] unable to write password hash: %v", err)
+	}
 	passwSum := passwHash.Sum(nil)
 	return func(pw string) bool {
 		pwHash := sha1.New()
-		pwHash.Write([]byte(pw))
+		if _, err := pwHash.Write([]byte(pw)); err != nil {
+			log.Printf("[ERROR] unable to write password hash: %v", err)
+		}
 		pwSum := pwHash.Sum(nil)
 		return subtle.ConstantTimeCompare([]byte(pwSum), []byte(passwSum)) == 1
 	}

caddyhttp/browse/browse.go

@@ -59,34 +59,34 @@ type Config struct {
 
 // A Listing is the context used to fill out a template.
 type Listing struct {
-	// The name of the directory (the last element of the path)
+	// The name of the directory (the last element of the path).
 	Name string
 
-	// The full path of the request
+	// The full path of the request.
 	Path string
 
-	// Whether the parent directory is browsable
+	// Whether the parent directory is browse-able.
 	CanGoUp bool
 
-	// The items (files and folders) in the path
+	// The items (files and folders) in the path.
 	Items []FileInfo
 
-	// The number of directories in the listing
+	// The number of directories in the listing.
 	NumDirs int
 
-	// The number of files (items that aren't directories) in the listing
+	// The number of files (items that aren't directories) in the listing.
 	NumFiles int
 
-	// Which sorting order is used
+	// Which sorting order is used.
 	Sort string
 
-	// And which order
+	// And which order.
 	Order string
 
-	// If ≠0 then Items have been limited to that many elements
+	// If ≠0 then Items have been limited to that many elements.
 	ItemsLimitedTo int
 
-	// Optional custom variables for use in browse templates
+	// Optional custom variables for use in browse templates.
 	User interface{}
 
 	httpserver.Context
@@ -244,7 +244,7 @@ func (l Listing) applySort() {
 
 func directoryListing(files []os.FileInfo, canGoUp bool, urlPath string, config *Config) (Listing, bool) {
 	var (
-		fileinfos           []FileInfo
+		fileInfos           []FileInfo
 		dirCount, fileCount int
 		hasIndexFile        bool
 	)
@@ -272,14 +272,14 @@ func directoryListing(files []os.FileInfo, canGoUp bool, urlPath string, config
 			continue
 		}
 
-		url := url.URL{Path: "./" + name} // prepend with "./" to fix paths with ':' in the name
+		u := url.URL{Path: "./" + name} // prepend with "./" to fix paths with ':' in the name
 
-		fileinfos = append(fileinfos, FileInfo{
+		fileInfos = append(fileInfos, FileInfo{
 			IsDir:     isDir,
 			IsSymlink: isSymlink(f),
 			Name:      f.Name(),
 			Size:      f.Size(),
-			URL:       url.String(),
+			URL:       u.String(),
 			ModTime:   f.ModTime().UTC(),
 			Mode:      f.Mode(),
 		})
@@ -289,7 +289,7 @@ func directoryListing(files []os.FileInfo, canGoUp bool, urlPath string, config
 		Name:     path.Base(urlPath),
 		Path:     urlPath,
 		CanGoUp:  canGoUp,
-		Items:    fileinfos,
+		Items:    fileInfos,
 		NumDirs:  dirCount,
 		NumFiles: fileCount,
 	}, hasIndexFile
@@ -504,7 +504,7 @@ func (b Browse) ServeListing(w http.ResponseWriter, r *http.Request, requestedFi
 
 	}
 
-	buf.WriteTo(w)
+	_, _ = buf.WriteTo(w)
 
 	return http.StatusOK, nil
 }

caddyhttp/fastcgi/fastcgi_test.go

@@ -16,6 +16,7 @@ package fastcgi
 
 import (
 	"context"
+	"log"
 	"net"
 	"net/http"
 	"net/http/fcgi"
@@ -39,11 +40,20 @@ func TestServeHTTP(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Unable to create listener for test: %v", err)
 	}
-	defer listener.Close()
-	go fcgi.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Length", bodyLenStr)
-		w.Write([]byte(body))
-	}))
+	defer func() { _ = listener.Close() }()
+
+	go func() {
+		err := fcgi.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Length", bodyLenStr)
+			_, err := w.Write([]byte(body))
+			if err != nil {
+				log.Printf("[ERROR] unable to write header: %v", err)
+			}
+		}))
+		if err != nil {
+			log.Printf("[ERROR] unable to start server: %v", err)
+		}
+	}()
 
 	handler := Handler{
 		Next:  nil,
@@ -147,15 +157,15 @@ func TestBuildEnv(t *testing.T) {
 		SplitPath:  ".php",
 		IndexFiles: []string{"index.php"},
 	}
-	url, err := url.Parse("http://localhost:2015/fgci_test.php?test=foobar")
+	u, err := url.Parse("http://localhost:2015/fgci_test.php?test=foobar")
 	if err != nil {
 		t.Error("Unexpected error:", err.Error())
 	}
 
 	var newReq = func() *http.Request {
 		r := http.Request{
 			Method:     "GET",
-			URL:        url,
+			URL:        u,
 			Proto:      "HTTP/1.1",
 			ProtoMajor: 1,
 			ProtoMinor: 1,
@@ -274,7 +284,7 @@ func TestReadTimeout(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Test %d: Unable to create listener for test: %v", i, err)
 		}
-		defer listener.Close()
+		defer func() { _ = listener.Close() }()
 
 		handler := Handler{
 			Next: nil,
@@ -293,11 +303,16 @@ func TestReadTimeout(t *testing.T) {
 		w := httptest.NewRecorder()
 
 		wg.Add(1)
-		go fcgi.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			time.Sleep(test.sleep)
-			w.WriteHeader(http.StatusOK)
-			wg.Done()
-		}))
+		go func() {
+			err := fcgi.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				time.Sleep(test.sleep)
+				w.WriteHeader(http.StatusOK)
+				wg.Done()
+			}))
+			if err != nil {
+				log.Printf("[ERROR] unable to start server: %v", err)
+			}
+		}()
 
 		got, err := handler.ServeHTTP(w, r)
 		if test.shouldErr {
@@ -334,7 +349,7 @@ func TestSendTimeout(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Test %d: Unable to create listener for test: %v", i, err)
 		}
-		defer listener.Close()
+		defer func() { _ = listener.Close() }()
 
 		handler := Handler{
 			Next: nil,
@@ -352,9 +367,14 @@ func TestSendTimeout(t *testing.T) {
 		}
 		w := httptest.NewRecorder()
 
-		go fcgi.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			w.WriteHeader(http.StatusOK)
-		}))
+		go func() {
+			err := fcgi.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(http.StatusOK)
+			}))
+			if err != nil {
+				log.Printf("[ERROR] unable to start server: %v", err)
+			}
+		}()
 
 		got, err := handler.ServeHTTP(w, r)
 		if test.shouldErr {

caddyhttp/fastcgi/fcgiclient.go

@@ -175,15 +175,13 @@ func (rec *record) read(r io.Reader) (buf []byte, err error) {
 // FCGIClient implements a FastCGI client, which is a standard for
 // interfacing external applications with Web servers.
 type FCGIClient struct {
-	mutex       sync.Mutex
-	rwc         io.ReadWriteCloser
-	h           header
-	buf         bytes.Buffer
-	stderr      bytes.Buffer
-	keepAlive   bool
-	reqID       uint16
-	readTimeout time.Duration
-	sendTimeout time.Duration
+	mutex     sync.Mutex
+	rwc       io.ReadWriteCloser
+	h         header
+	buf       bytes.Buffer
+	stderr    bytes.Buffer
+	keepAlive bool
+	reqID     uint16
 }
 
 // DialWithDialerContext connects to the fcgi responder at the specified network address, using custom net.Dialer
@@ -397,7 +395,7 @@ func (c *FCGIClient) Do(p map[string]string, req io.Reader) (r io.Reader, err er
 
 	body := newWriter(c, Stdin)
 	if req != nil {
-		io.Copy(body, req)
+		_, _ = io.Copy(body, req)
 	}
 	body.Close()