enable all go-critic

Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>

.golangci.yml

@@ -41,6 +41,13 @@ linters:
     gocritic:
       disabled-checks:
         - captLocal
+        - commentedOutCode
+        - deferInLoop
+        - hexLiteral
+        - hugeParam
+        - tooManyResultsChecker
+        - unnamedResult
+      enable-all: true
     gomodguard:
       blocked:
         modules:

cpu/cpu_linux.go

@@ -135,7 +135,7 @@ func finishCPUInfo(ctx context.Context, c *InfoStat) {
 	var err error
 	var value float64
 
-	if len(c.CoreID) == 0 {
+	if c.CoreID == "" {
 		lines, err = common.ReadLines(sysCPUPath(ctx, c.CPU, "topology/core_id"))
 		if err == nil {
 			c.CoreID = lines[0]

cpu/cpu_plan9_test.go

@@ -35,7 +35,7 @@ var timesTests = []struct {
 func TestTimesPlan9(t *testing.T) {
 	for _, tt := range timesTests {
 		t.Run(tt.mockedRootFS, func(t *testing.T) {
-			t.Setenv("HOST_ROOT", filepath.Join("testdata/plan9", tt.mockedRootFS))
+			t.Setenv("HOST_ROOT", filepath.Join("testdata", "plan9", tt.mockedRootFS))
 			stats, err := Times(false)
 			common.SkipIfNotImplementedErr(t, err)
 			require.NoError(t, err)

cpu/cpu_solaris.go

@@ -140,8 +140,8 @@ func InfoWithContext(ctx context.Context) ([]InfoStat, error) {
 	}
 
 	result := make([]InfoStat, 0, len(flags))
-	for _, proc := range procs {
+	for i := range procs {
-		procWithFlags := proc
+		procWithFlags := procs[i]
 		procWithFlags.Flags = flags
 		result = append(result, procWithFlags)
 	}
@@ -149,7 +149,7 @@ func InfoWithContext(ctx context.Context) ([]InfoStat, error) {
 	return result, nil
 }
 
-var flagsMatch = regexp.MustCompile(`[\w\.]+`)
+var flagsMatch = regexp.MustCompile(`[\w.]+`)
 
 func parseISAInfo(cmdOutput string) ([]string, error) {
 	words := flagsMatch.FindAllString(cmdOutput, -1)

cpu/cpu_test.go

@@ -2,7 +2,6 @@
 package cpu
 
 import (
-	"fmt"
 	"os"
 	"runtime"
 	"testing"
@@ -80,7 +79,7 @@ func TestTimeStat_String(t *testing.T) {
 		Idle:   300.1,
 	}
 	e := `{"cpu":"cpu0","user":100.1,"system":200.1,"idle":300.1,"nice":0.0,"iowait":0.0,"irq":0.0,"softirq":0.0,"steal":0.0,"guest":0.0,"guestNice":0.0}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "CPUTimesStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "CPUTimesStat string is invalid: %v", v)
 }
 
 func TestInfo(t *testing.T) {

disk/disk_darwin.go

@@ -35,7 +35,8 @@ func PartitionsWithContext(_ context.Context, _ bool) ([]PartitionStat, error) {
 	// to prevent accessing uninitialized entries.
 	// https://github.com/shirou/gopsutil/issues/1390
 	fs = fs[:count]
-	for _, stat := range fs {
+	for i := range fs {
+		stat := &fs[i]
 		opts := []string{"rw"}
 		if stat.Flags&unix.MNT_RDONLY != 0 {
 			opts = []string{"ro"}
@@ -131,8 +132,10 @@ func SerialNumberWithContext(ctx context.Context, _ string) (string, error) {
 
 	// Extract all serial numbers into a single string
 	var serialNumbers []string
-	for _, spnvmeData := range data.SPNVMeDataType {
+	for i := range data.SPNVMeDataType {
-		for _, item := range spnvmeData.Items {
+		spnvmeData := &data.SPNVMeDataType[i]
+		for j := range spnvmeData.Items {
+			item := &spnvmeData.Items[j]
 			serialNumbers = append(serialNumbers, item.DeviceSerial)
 		}
 	}

disk/disk_freebsd.go

@@ -33,7 +33,8 @@ func PartitionsWithContext(_ context.Context, _ bool) ([]PartitionStat, error) {
 		return ret, err
 	}
 
-	for _, stat := range fs {
+	for i := range fs {
+		stat := &fs[i]
 		opts := []string{"rw"}
 		if stat.Flags&unix.MNT_RDONLY != 0 {
 			opts = []string{"ro"}
@@ -182,7 +183,8 @@ func SerialNumberWithContext(ctx context.Context, name string) (string, error) {
 			break
 		}
 	}
-	if err = s.Err(); err != nil {
+	err = s.Err()
+	if err != nil {
 		return "", err
 	}
 	return serial, nil

disk/disk_linux.go

@@ -486,7 +486,7 @@ func IOCountersWithContext(ctx context.Context, names ...string) (map[string]IOC
 	return ret, nil
 }
 
-func udevData(ctx context.Context, major uint32, minor uint32, name string) (string, error) {
+func udevData(ctx context.Context, major, minor uint32, name string) (string, error) {
 	udevDataPath := common.HostRunWithContext(ctx, fmt.Sprintf("udev/data/b%d:%d", major, minor))
 	if f, err := os.Open(udevDataPath); err == nil {
 		defer f.Close()

disk/disk_netbsd.go

@@ -57,7 +57,8 @@ func PartitionsWithContext(_ context.Context, _ bool) ([]PartitionStat, error) {
 		return ret, err
 	}
 
-	for _, stat := range buf {
+	for i := range buf {
+		stat := &buf[i]
 		opts := []string{"rw"}
 		if stat.Flag&MNT_RDONLY != 0 {
 			opts = []string{"rw"}

disk/disk_openbsd.go

@@ -27,7 +27,8 @@ func PartitionsWithContext(_ context.Context, _ bool) ([]PartitionStat, error) {
 		return ret, err
 	}
 
-	for _, stat := range fs {
+	for i := range fs {
+		stat := &fs[i]
 		opts := []string{"rw"}
 		if stat.F_flags&unix.MNT_RDONLY != 0 {
 			opts = []string{"rw"}

disk/disk_test.go

@@ -2,7 +2,6 @@
 package disk
 
 import (
-	"fmt"
 	"runtime"
 	"sync"
 	"testing"
@@ -81,7 +80,7 @@ func TestUsageStat_String(t *testing.T) {
 		Fstype:            "ext4",
 	}
 	e := `{"path":"/","fstype":"ext4","total":1000,"free":2000,"used":3000,"usedPercent":50.1,"inodesTotal":4000,"inodesUsed":5000,"inodesFree":6000,"inodesUsedPercent":49.1}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "DiskUsageStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "DiskUsageStat string is invalid: %v", v)
 }
 
 func TestPartitionStat_String(t *testing.T) {
@@ -92,7 +91,7 @@ func TestPartitionStat_String(t *testing.T) {
 		Opts:       []string{"ro"},
 	}
 	e := `{"device":"sd01","mountpoint":"/","fstype":"ext4","opts":["ro"]}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "DiskUsageStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "DiskUsageStat string is invalid: %v", v)
 }
 
 func TestIOCountersStat_String(t *testing.T) {
@@ -105,5 +104,5 @@ func TestIOCountersStat_String(t *testing.T) {
 		SerialNumber: "SERIAL",
 	}
 	e := `{"readCount":100,"mergedReadCount":0,"writeCount":200,"mergedWriteCount":0,"readBytes":300,"writeBytes":400,"readTime":0,"writeTime":0,"iopsInProgress":0,"ioTime":0,"weightedIO":0,"name":"sd01","serialNumber":"SERIAL","label":""}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "DiskUsageStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "DiskUsageStat string is invalid: %v", v)
 }

disk/disk_windows.go

@@ -192,40 +192,41 @@ func IOCountersWithContext(_ context.Context, names ...string) (map[string]IOCou
 		return drivemap, err
 	}
 	for _, v := range lpBuffer[:lpBufferLen] {
-		if 'A' <= v && v <= 'Z' {
+		if 'A' > v || v > 'Z' {
-			path := string(rune(v)) + ":"
+			continue
-			typepath, _ := windows.UTF16PtrFromString(path)
+		}
-			typeret := windows.GetDriveType(typepath)
+		path := string(rune(v)) + ":"
-			if typeret != windows.DRIVE_FIXED {
+		typepath, _ := windows.UTF16PtrFromString(path)
+		typeret := windows.GetDriveType(typepath)
+		if typeret != windows.DRIVE_FIXED {
+			continue
+		}
+		szDevice := `\\.\` + path
+		const IOCTL_DISK_PERFORMANCE = 0x70020
+		h, err := windows.CreateFile(syscall.StringToUTF16Ptr(szDevice), 0, windows.FILE_SHARE_READ|windows.FILE_SHARE_WRITE, nil, windows.OPEN_EXISTING, 0, 0)
+		if err != nil {
+			if errors.Is(err, windows.ERROR_FILE_NOT_FOUND) {
 				continue
 			}
-			szDevice := `\\.\` + path
+			return drivemap, err
-			const IOCTL_DISK_PERFORMANCE = 0x70020
+		}
-			h, err := windows.CreateFile(syscall.StringToUTF16Ptr(szDevice), 0, windows.FILE_SHARE_READ|windows.FILE_SHARE_WRITE, nil, windows.OPEN_EXISTING, 0, 0)
+		defer windows.CloseHandle(h)
-			if err != nil {
-				if errors.Is(err, windows.ERROR_FILE_NOT_FOUND) {
-					continue
-				}
-				return drivemap, err
-			}
-			defer windows.CloseHandle(h)
 
-			var diskPerformanceSize uint32
+		var diskPerformanceSize uint32
-			err = windows.DeviceIoControl(h, IOCTL_DISK_PERFORMANCE, nil, 0, (*byte)(unsafe.Pointer(&diskPerformance)), uint32(unsafe.Sizeof(diskPerformance)), &diskPerformanceSize, nil)
+		err = windows.DeviceIoControl(h, IOCTL_DISK_PERFORMANCE, nil, 0, (*byte)(unsafe.Pointer(&diskPerformance)), uint32(unsafe.Sizeof(diskPerformance)), &diskPerformanceSize, nil)
-			if err != nil {
+		if err != nil {
-				return drivemap, err
+			return drivemap, err
-			}
+		}
 
-			if len(names) == 0 || common.StringsHas(names, path) {
+		if len(names) == 0 || common.StringsHas(names, path) {
-				drivemap[path] = IOCountersStat{
+			drivemap[path] = IOCountersStat{
-					ReadBytes:  uint64(diskPerformance.BytesRead),
+				ReadBytes:  uint64(diskPerformance.BytesRead),
-					WriteBytes: uint64(diskPerformance.BytesWritten),
+				WriteBytes: uint64(diskPerformance.BytesWritten),
-					ReadCount:  uint64(diskPerformance.ReadCount),
+				ReadCount:  uint64(diskPerformance.ReadCount),
-					WriteCount: uint64(diskPerformance.WriteCount),
+				WriteCount: uint64(diskPerformance.WriteCount),
-					ReadTime:   uint64(diskPerformance.ReadTime / 10000 / 1000), // convert to ms: https://github.com/giampaolo/psutil/issues/1012
+				ReadTime:   uint64(diskPerformance.ReadTime / 10000 / 1000), // convert to ms: https://github.com/giampaolo/psutil/issues/1012
-					WriteTime:  uint64(diskPerformance.WriteTime / 10000 / 1000),
+				WriteTime:  uint64(diskPerformance.WriteTime / 10000 / 1000),
-					Name:       path,
+				Name:       path,
-				}
 			}
 		}
 	}

docker/docker_linux.go

@@ -87,7 +87,7 @@ func GetDockerIDListWithContext(ctx context.Context) ([]string, error) {
 // containerID is same as docker id if you use docker.
 // If you use container via systemd.slice, you could use
 // containerID = docker-<container id>.scope and base=/sys/fs/cgroup/cpuacct/system.slice/
-func CgroupCPU(containerID string, base string) (*CgroupCPUStat, error) {
+func CgroupCPU(containerID, base string) (*CgroupCPUStat, error) {
 	return CgroupCPUWithContext(context.Background(), containerID, base)
 }
 
@@ -95,18 +95,18 @@ func CgroupCPU(containerID string, base string) (*CgroupCPUStat, error) {
 // containerID is same as docker id if you use docker.
 // If you use container via systemd.slice, you could use
 // containerID = docker-<container id>.scope and base=/sys/fs/cgroup/cpuacct/system.slice/
-func CgroupCPUUsage(containerID string, base string) (float64, error) {
+func CgroupCPUUsage(containerID, base string) (float64, error) {
 	return CgroupCPUUsageWithContext(context.Background(), containerID, base)
 }
 
-func CgroupCPUWithContext(ctx context.Context, containerID string, base string) (*CgroupCPUStat, error) {
+func CgroupCPUWithContext(ctx context.Context, containerID, base string) (*CgroupCPUStat, error) {
 	statfile := getCgroupFilePath(ctx, containerID, base, "cpuacct", "cpuacct.stat")
 	lines, err := common.ReadLines(statfile)
 	if err != nil {
 		return nil, err
 	}
 	// empty containerID means all cgroup
-	if len(containerID) == 0 {
+	if containerID == "" {
 		containerID = "all"
 	}
 
@@ -166,15 +166,15 @@ func CgroupCPUDockerUsageWithContext(ctx context.Context, containerID string) (f
 	return CgroupCPUUsageWithContext(ctx, containerID, common.HostSysWithContext(ctx, "fs/cgroup/cpuacct/docker"))
 }
 
-func CgroupMem(containerID string, base string) (*CgroupMemStat, error) {
+func CgroupMem(containerID, base string) (*CgroupMemStat, error) {
 	return CgroupMemWithContext(context.Background(), containerID, base)
 }
 
-func CgroupMemWithContext(ctx context.Context, containerID string, base string) (*CgroupMemStat, error) {
+func CgroupMemWithContext(ctx context.Context, containerID, base string) (*CgroupMemStat, error) {
 	statfile := getCgroupFilePath(ctx, containerID, base, "memory", "memory.stat")
 
 	// empty containerID means all cgroup
-	if len(containerID) == 0 {
+	if containerID == "" {
 		containerID = "all"
 	}
 	lines, err := common.ReadLines(statfile)
@@ -276,7 +276,7 @@ func CgroupMemDockerWithContext(ctx context.Context, containerID string) (*Cgrou
 
 // getCgroupFilePath constructs file path to get targeted stats file.
 func getCgroupFilePath(ctx context.Context, containerID, base, target, file string) string {
-	if len(base) == 0 {
+	if base == "" {
 		base = common.HostSysWithContext(ctx, fmt.Sprintf("fs/cgroup/%s/docker", target))
 	}
 	statfile := path.Join(base, containerID, file)

docker/docker_notlinux.go

@@ -33,11 +33,11 @@ func GetDockerIDListWithContext(_ context.Context) ([]string, error) {
 // containerID is same as docker id if you use docker.
 // If you use container via systemd.slice, you could use
 // containerID = docker-<container id>.scope and base=/sys/fs/cgroup/cpuacct/system.slice/
-func CgroupCPU(containerID string, base string) (*CgroupCPUStat, error) {
+func CgroupCPU(containerID, base string) (*CgroupCPUStat, error) {
 	return CgroupCPUWithContext(context.Background(), containerID, base)
 }
 
-func CgroupCPUWithContext(_ context.Context, _ string, _ string) (*CgroupCPUStat, error) {
+func CgroupCPUWithContext(_ context.Context, _, _ string) (*CgroupCPUStat, error) {
 	return nil, ErrCgroupNotAvailable
 }
 
@@ -49,11 +49,11 @@ func CgroupCPUDockerWithContext(ctx context.Context, containerID string) (*Cgrou
 	return CgroupCPUWithContext(ctx, containerID, common.HostSysWithContext(ctx, "fs/cgroup/cpuacct/docker"))
 }
 
-func CgroupMem(containerID string, base string) (*CgroupMemStat, error) {
+func CgroupMem(containerID, base string) (*CgroupMemStat, error) {
 	return CgroupMemWithContext(context.Background(), containerID, base)
 }
 
-func CgroupMemWithContext(_ context.Context, _ string, _ string) (*CgroupMemStat, error) {
+func CgroupMemWithContext(_ context.Context, _, _ string) (*CgroupMemStat, error) {
 	return nil, ErrCgroupNotAvailable
 }
 

host/host_aix.go

@@ -160,7 +160,7 @@ func UsersWithContext(ctx context.Context) ([]UserStat, error) {
 }
 
 // Much of this function could be static. However, to be future proofed, I've made it call the OS for the information in all instances.
-func PlatformInformationWithContext(ctx context.Context) (platform string, family string, version string, err error) {
+func PlatformInformationWithContext(ctx context.Context) (platform, family, version string, err error) {
 	// Set the platform (which should always, and only be, "AIX") from `uname -s`
 	out, err := invoke.CommandWithContext(ctx, "uname", "-s")
 	if err != nil {

host/host_linux.go

@@ -170,7 +170,7 @@ func getlsbStruct(ctx context.Context) (*lsbStruct, error) {
 	return ret, nil
 }
 
-func PlatformInformationWithContext(ctx context.Context) (platform string, family string, version string, err error) {
+func PlatformInformationWithContext(ctx context.Context) (platform, family, version string, err error) {
 	lsb, err := getlsbStruct(ctx)
 	if err != nil {
 		lsb = &lsbStruct{}

host/host_solaris.go

@@ -67,7 +67,7 @@ func numProcs(_ context.Context) (uint64, error) {
 	return uint64(len(dirs)), nil
 }
 
-var kstatMatch = regexp.MustCompile(`([^\s]+)[\s]+([^\s]*)`)
+var kstatMatch = regexp.MustCompile(`(\S+)\s+(\S*)`)
 
 func BootTimeWithContext(ctx context.Context) (uint64, error) {
 	out, err := invoke.CommandWithContext(ctx, "kstat", "-p", "unix:0:system_misc:boot_time")

host/host_test.go

@@ -2,7 +2,6 @@
 package host
 
 import (
-	"fmt"
 	"os"
 	"sync"
 	"testing"
@@ -86,7 +85,7 @@ func TestInfoStat_String(t *testing.T) {
 		KernelArch: "x86_64",
 	}
 	e := `{"hostname":"test","uptime":3000,"bootTime":1447040000,"procs":100,"os":"linux","platform":"ubuntu","platformFamily":"","platformVersion":"","kernelVersion":"","kernelArch":"x86_64","virtualizationSystem":"","virtualizationRole":"","hostId":"edfd25ff-3c9c-b1a4-e660-bd826495ad35"}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "HostInfoStat string is invalid:\ngot  %v\nwant %v", v, e)
+	assert.JSONEqf(t, e, v.String(), "HostInfoStat string is invalid:\ngot  %v\nwant %v", v, e)
 }
 
 func TestUserStat_String(t *testing.T) {
@@ -97,7 +96,7 @@ func TestUserStat_String(t *testing.T) {
 		Started:  100,
 	}
 	e := `{"user":"user","terminal":"term","host":"host","started":100}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "UserStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "UserStat string is invalid: %v", v)
 }
 
 func TestGuid(t *testing.T) {

host/host_windows.go

@@ -136,7 +136,7 @@ func BootTimeWithContext(_ context.Context) (uint64, error) {
 	return t, nil
 }
 
-func PlatformInformationWithContext(_ context.Context) (platform string, family string, version string, err error) {
+func PlatformInformationWithContext(_ context.Context) (platform, family, version string, err error) {
 	platform, family, _, displayVersion, err := platformInformation()
 	if err != nil {
 		return "", "", "", err

internal/common/common.go

@@ -115,7 +115,7 @@ func ReadLines(filename string) ([]string, error) {
 }
 
 // ReadLine reads a file and returns the first occurrence of a line that is prefixed with prefix.
-func ReadLine(filename string, prefix string) (string, error) {
+func ReadLine(filename, prefix string) (string, error) {
 	f, err := os.Open(filename)
 	if err != nil {
 		return "", err
@@ -156,7 +156,7 @@ func ReadLinesOffsetN(filename string, offset uint, n int) ([]string, error) {
 	for i := uint(0); i < uint(n)+offset || n < 0; i++ {
 		line, err := r.ReadString('\n')
 		if err != nil {
-			if err == io.EOF && len(line) > 0 {
+			if err == io.EOF && line != "" {
 				ret = append(ret, strings.Trim(line, "\n"))
 			}
 			break
@@ -349,7 +349,7 @@ func PathExistsWithContents(filename string) bool {
 
 // GetEnvWithContext retrieves the environment variable key. If it does not exist it returns the default.
 // The context may optionally contain a map superseding os.EnvKey.
-func GetEnvWithContext(ctx context.Context, key string, dfault string, combineWith ...string) string {
+func GetEnvWithContext(ctx context.Context, key, dfault string, combineWith ...string) string {
 	var value string
 	if env, ok := ctx.Value(common.EnvKey).(common.EnvMap); ok {
 		value = env[common.EnvKeyType(key)]
@@ -365,7 +365,7 @@ func GetEnvWithContext(ctx context.Context, key string, dfault string, combineWi
 }
 
 // GetEnv retrieves the environment variable key. If it does not exist it returns the default.
-func GetEnv(key string, dfault string, combineWith ...string) string {
+func GetEnv(key, dfault string, combineWith ...string) string {
 	value := os.Getenv(key)
 	if value == "" {
 		value = dfault

internal/common/common_linux.go

@@ -317,11 +317,11 @@ func VirtualizationWithContext(ctx context.Context) (string, string, error) {
 	return system, role, nil
 }
 
-func GetOSRelease() (platform string, version string, err error) {
+func GetOSRelease() (platform, version string, err error) {
 	return GetOSReleaseWithContext(context.Background())
 }
 
-func GetOSReleaseWithContext(ctx context.Context) (platform string, version string, err error) {
+func GetOSReleaseWithContext(ctx context.Context) (platform, version string, err error) {
 	contents, err := ReadLines(HostEtcWithContext(ctx, "os-release"))
 	if err != nil {
 		return "", "", nil // return empty

internal/common/common_unix.go

@@ -33,7 +33,7 @@ func CallLsofWithContext(ctx context.Context, invoke Invoker, pid int32, args ..
 
 	var ret []string
 	for _, l := range lines[1:] {
-		if len(l) == 0 {
+		if l == "" {
 			continue
 		}
 		ret = append(ret, l)

load/load_aix_nocgo.go

@@ -4,6 +4,7 @@
 package load
 
 import (
+	"bytes"
 	"context"
 	"regexp"
 	"strconv"
@@ -20,7 +21,7 @@ func AvgWithContext(ctx context.Context) (*AvgStat, error) {
 		return nil, err
 	}
 
-	idx := strings.Index(string(line), "load average:")
+	idx := bytes.Index(line, []byte("load average:"))
 	if idx < 0 {
 		return nil, common.ErrNotImplementedError
 	}

load/load_solaris.go

@@ -45,7 +45,8 @@ func AvgWithContext(ctx context.Context) (*AvgStat, error) {
 		}
 		*tgt = float64(v) / (1 << 8)
 	}
-	if err = scanner.Err(); err != nil {
+	err = scanner.Err()
+	if err != nil {
 		return nil, err
 	}
 

load/load_test.go

@@ -2,7 +2,6 @@
 package load
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -28,7 +27,7 @@ func TestAvgStat_String(t *testing.T) {
 		Load15: 30.1,
 	}
 	e := `{"load1":10.1,"load5":20.1,"load15":30.1}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "LoadAvgStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "LoadAvgStat string is invalid: %v", v)
 	t.Log(e)
 }
 
@@ -51,7 +50,7 @@ func TestMiscStatString(t *testing.T) {
 		Ctxt:         3,
 	}
 	e := `{"procsTotal":4,"procsCreated":5,"procsRunning":1,"procsBlocked":2,"ctxt":3}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "TestMiscString string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "TestMiscString string is invalid: %v", v)
 	t.Log(e)
 }
 

mem/mem_linux_test.go

@@ -126,7 +126,7 @@ var virtualMemoryTests = []struct {
 func TestVirtualMemoryLinux(t *testing.T) {
 	for _, tt := range virtualMemoryTests {
 		t.Run(tt.mockedRootFS, func(t *testing.T) {
-			t.Setenv("HOST_PROC", filepath.Join("testdata/linux/virtualmemory/", tt.mockedRootFS, "proc"))
+			t.Setenv("HOST_PROC", filepath.Join("testdata", "linux", "virtualmemory", tt.mockedRootFS, "proc"))
 
 			stat, err := VirtualMemory()
 			common.SkipIfNotImplementedErr(t, err)

mem/mem_test.go

@@ -2,7 +2,6 @@
 package mem
 
 import (
-	"fmt"
 	"runtime"
 	"testing"
 
@@ -77,7 +76,7 @@ func TestVirtualMemoryStat_String(t *testing.T) {
 	}
 	t.Log(v)
 	e := `{"total":10,"available":20,"used":30,"usedPercent":30.1,"free":40,"active":0,"inactive":0,"wired":0,"laundry":0,"buffers":0,"cached":0,"writeBack":0,"dirty":0,"writeBackTmp":0,"shared":0,"slab":0,"sreclaimable":0,"sunreclaim":0,"pageTables":0,"swapCached":0,"commitLimit":0,"committedAS":0,"highTotal":0,"highFree":0,"lowTotal":0,"lowFree":0,"swapTotal":0,"swapFree":0,"mapped":0,"vmallocTotal":0,"vmallocUsed":0,"vmallocChunk":0,"hugePagesTotal":0,"hugePagesFree":0,"hugePagesRsvd":0,"hugePagesSurp":0,"hugePageSize":0,"anonHugePages":0}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "VirtualMemoryStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "VirtualMemoryStat string is invalid: %v", v)
 }
 
 func TestSwapMemoryStat_String(t *testing.T) {
@@ -94,7 +93,7 @@ func TestSwapMemoryStat_String(t *testing.T) {
 		PgMajFault:  6,
 	}
 	e := `{"total":10,"used":30,"free":40,"usedPercent":30.1,"sin":1,"sout":2,"pgIn":3,"pgOut":4,"pgFault":5,"pgMajFault":6}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "SwapMemoryStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "SwapMemoryStat string is invalid: %v", v)
 }
 
 func TestSwapDevices(t *testing.T) {

net/net.go

@@ -94,7 +94,7 @@ type ConntrackStat struct {
 	SearchRestart uint32 `json:"searchRestart"` // Conntrack table lookups restarted due to hashtable resizes
 }
 
-func NewConntrackStat(e uint32, s uint32, f uint32, n uint32, inv uint32, ign uint32, del uint32, dlst uint32, ins uint32, insfail uint32, drop uint32, edrop uint32, ie uint32, en uint32, ec uint32, ed uint32, sr uint32) *ConntrackStat {
+func NewConntrackStat(e, s, f, n, inv, ign, del, dlst, ins, insfail, drop, edrop, ie, en, ec, ed, sr uint32) *ConntrackStat {
 	return &ConntrackStat{
 		Entries:       e,
 		Searched:      s,

net/net_aix.go

@@ -83,7 +83,7 @@ var portMatch = regexp.MustCompile(`(.*)\.(\d+)$`)
 
 // This function only works for netstat returning addresses with a "."
 // before the port (0.0.0.0.22 instead of 0.0.0.0:22).
-func parseNetstatAddr(local string, remote string, family uint32) (laddr Addr, raddr Addr, err error) {
+func parseNetstatAddr(local, remote string, family uint32) (laddr, raddr Addr, err error) {
 	parse := func(l string) (Addr, error) {
 		matches := portMatch.FindStringSubmatch(l)
 		if matches == nil {
@@ -183,7 +183,7 @@ func hasCorrectInetProto(kind, proto string) bool {
 	return false
 }
 
-func parseNetstatA(output string, kind string) ([]ConnectionStat, error) {
+func parseNetstatA(output, kind string) ([]ConnectionStat, error) {
 	var ret []ConnectionStat
 	lines := strings.Split(string(output), "\n")
 

net/net_linux.go

@@ -793,7 +793,7 @@ func processUnix(file string, kind netConnectionKindType, inodes map[string][]in
 	return ret, nil
 }
 
-func updateMap(src map[string][]inodeMap, add map[string][]inodeMap) map[string][]inodeMap {
+func updateMap(src, add map[string][]inodeMap) map[string][]inodeMap {
 	for key, value := range add {
 		a, exists := src[key]
 		if !exists {

net/net_openbsd.go

@@ -217,7 +217,7 @@ func parseNetstatLine(line string) (ConnectionStat, error) {
 	return n, nil
 }
 
-func parseNetstatAddr(local string, remote string, family uint32) (laddr Addr, raddr Addr, err error) {
+func parseNetstatAddr(local, remote string, family uint32) (laddr, raddr Addr, err error) {
 	parse := func(l string) (Addr, error) {
 		matches := portMatch.FindStringSubmatch(l)
 		if matches == nil {
@@ -260,11 +260,7 @@ func ConnectionsWithContext(ctx context.Context, kind string) ([]ConnectionStat,
 	switch strings.ToLower(kind) {
 	default:
 		fallthrough
-	case "":
+	case "", "all", "inet":
-		fallthrough
-	case "all":
-		fallthrough
-	case "inet":
 		// nothing to add
 	case "inet4":
 		args = append(args, "-finet")

net/net_test.go

@@ -16,7 +16,7 @@ import (
 func TestAddrString(t *testing.T) {
 	v := Addr{IP: "192.168.0.1", Port: 8000}
 
-	s := fmt.Sprintf("%v", v)
+	s := v.String()
 	assert.JSONEqf(t, `{"ip":"192.168.0.1","port":8000}`, s, "Addr string is invalid: %v", v)
 }
 
@@ -26,7 +26,7 @@ func TestIOCountersStatString(t *testing.T) {
 		BytesSent: 100,
 	}
 	e := `{"name":"test","bytesSent":100,"bytesRecv":0,"packetsSent":0,"packetsRecv":0,"errin":0,"errout":0,"dropin":0,"dropout":0,"fifoin":0,"fifoout":0}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "NetIOCountersStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "NetIOCountersStat string is invalid: %v", v)
 }
 
 func TestProtoCountersStatString(t *testing.T) {
@@ -39,7 +39,7 @@ func TestProtoCountersStatString(t *testing.T) {
 		},
 	}
 	e := `{"protocol":"tcp","stats":{"ActiveOpens":4000,"MaxConn":-1,"PassiveOpens":3000}}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "NetProtoCountersStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "NetProtoCountersStat string is invalid: %v", v)
 }
 
 func TestConnectionStatString(t *testing.T) {
@@ -50,7 +50,7 @@ func TestConnectionStatString(t *testing.T) {
 		Uids:   []int32{10, 10},
 	}
 	e := `{"fd":10,"family":10,"type":10,"localaddr":{"ip":"","port":0},"remoteaddr":{"ip":"","port":0},"status":"","uids":[10,10],"pid":0}`
-	assert.JSONEqf(t, e, fmt.Sprintf("%v", v), "NetConnectionStat string is invalid: %v", v)
+	assert.JSONEqf(t, e, v.String(), "NetConnectionStat string is invalid: %v", v)
 }
 
 func TestIOCountersAll(t *testing.T) {
@@ -194,10 +194,10 @@ func TestInterfaceStatString(t *testing.T) {
 		Addrs:        InterfaceAddrList{{Addr: "1.2.3.4"}, {Addr: "5.6.7.8"}},
 	}
 
-	s := fmt.Sprintf("%v", v)
+	s := v.String()
 	assert.JSONEqf(t, `{"index":0,"mtu":1500,"name":"eth0","hardwareAddr":"01:23:45:67:89:ab","flags":["up","down"],"addrs":[{"addr":"1.2.3.4"},{"addr":"5.6.7.8"}]}`, s, "InterfaceStat string is invalid: %v", s)
 
 	list := InterfaceStatList{v, v}
-	s = fmt.Sprintf("%v", list)
+	s = list.String()
 	assert.JSONEqf(t, `[{"index":0,"mtu":1500,"name":"eth0","hardwareAddr":"01:23:45:67:89:ab","flags":["up","down"],"addrs":[{"addr":"1.2.3.4"},{"addr":"5.6.7.8"}]},{"index":0,"mtu":1500,"name":"eth0","hardwareAddr":"01:23:45:67:89:ab","flags":["up","down"],"addrs":[{"addr":"1.2.3.4"},{"addr":"5.6.7.8"}]}]`, s, "InterfaceStatList string is invalid: %v", s)
 }

net/net_unix.go

@@ -29,11 +29,7 @@ func ConnectionsPidWithContext(ctx context.Context, kind string, pid int32) ([]C
 	switch strings.ToLower(kind) {
 	default:
 		fallthrough
-	case "":
+	case "", "all", "inet":
-		fallthrough
-	case "all":
-		fallthrough
-	case "inet":
 		args = append(args, "tcp", "-i", "udp")
 	case "inet4":
 		args = append(args, "4")
@@ -135,7 +131,7 @@ func parseNetLine(line string) (ConnectionStat, error) {
 	return n, nil
 }
 
-func parseNetAddr(line string) (laddr Addr, raddr Addr, err error) {
+func parseNetAddr(line string) (laddr, raddr Addr, err error) {
 	parse := func(l string) (Addr, error) {
 		host, port, err := net.SplitHostPort(l)
 		if err != nil {

process/process_darwin.go

@@ -45,7 +45,8 @@ func pidsWithContext(_ context.Context) ([]int32, error) {
 		return ret, err
 	}
 
-	for _, proc := range kprocs {
+	for i := range kprocs {
+		proc := &kprocs[i]
 		ret = append(ret, int32(proc.Proc.P_pid))
 	}
 
@@ -74,7 +75,7 @@ func (p *Process) NameWithContext(ctx context.Context) (string, error) {
 		if err != nil {
 			return "", err
 		}
-		if len(cmdName) > 0 {
+		if cmdName != "" {
 			extendedName := filepath.Base(cmdName)
 			if strings.HasPrefix(extendedName, p.name) {
 				name = extendedName
@@ -238,7 +239,7 @@ func (p *Process) getKProc() (*unix.KinfoProc, error) {
 // Return value deletes Header line(you must not input wrong arg).
 // And splited by Space. Caller have responsibility to manage.
 // If passed arg pid is 0, get information from all process.
-func callPsWithContext(ctx context.Context, arg string, pid int32, threadOption bool, nameOption bool) ([][]string, error) {
+func callPsWithContext(ctx context.Context, arg string, pid int32, threadOption, nameOption bool) ([][]string, error) {
 	var cmd []string
 	switch {
 	case pid == 0: // will get from all processes.
@@ -396,7 +397,7 @@ func (p *Process) cmdlineSlice() ([]string, error) {
 	// of the process.
 	for _, arg := range args[1:] {
 		argStr = string(arg)
-		if len(argStr) > 0 {
+		if argStr != "" {
 			if nargs > 0 {
 				argSlice = append(argSlice, argStr)
 				nargs--

process/process_linux.go

@@ -358,7 +358,7 @@ func (p *Process) ChildrenWithContext(ctx context.Context) ([]*Process, error) {
 		if err != nil {
 			continue
 		}
-		if int32(ppid) == p.Pid {
+		if ppid == int64(p.Pid) {
 			np, err := NewProcessWithContext(ctx, int32(pid))
 			if err != nil {
 				continue
@@ -639,7 +639,7 @@ func (p *Process) fillFromfdWithContext(ctx context.Context) (int32, []*OpenFile
 	var openfiles []*OpenFilesStat
 	for _, fd := range fnames {
 		fpath := filepath.Join(statPath, fd)
-		filepath, err := os.Readlink(fpath)
+		path, err := os.Readlink(fpath)
 		if err != nil {
 			continue
 		}
@@ -648,7 +648,7 @@ func (p *Process) fillFromfdWithContext(ctx context.Context) (int32, []*OpenFile
 			return numFDs, openfiles, err
 		}
 		o := &OpenFilesStat{
-			Path: filepath,
+			Path: path,
 			Fd:   t,
 		}
 		openfiles = append(openfiles, o)

process/process_openbsd.go

@@ -358,7 +358,7 @@ func (p *Process) getKProc() (*KinfoProc, error) {
 	return &k, nil
 }
 
-func callKernProcSyscall(op int32, arg int32) ([]byte, uint64, error) {
+func callKernProcSyscall(op, arg int32) ([]byte, uint64, error) {
 	mib := []int32{CTLKern, KernProc, op, arg, sizeOfKinfoProc, 0}
 	mibptr := unsafe.Pointer(&mib[0])
 	miblen := uint64(len(mib))

process/process_posix.go

@@ -67,7 +67,8 @@ func getTerminalMap() (map[uint64]string, error) {
 
 	for _, name := range termfiles {
 		stat := unix.Stat_t{}
-		if err = unix.Stat(name, &stat); err != nil {
+		err = unix.Stat(name, &stat)
+		if err != nil {
 			return nil, err
 		}
 		rdev := uint64(stat.Rdev)

process/process_test.go

@@ -446,7 +446,7 @@ func TestConnections(t *testing.T) {
 
 	serverConnections := 0
 	for _, connection := range c {
-		if connection.Laddr.IP == tcpServerAddrIP && connection.Laddr.Port == uint32(tcpServerAddrPort) && connection.Raddr.Port != 0 {
+		if connection.Laddr.IP == tcpServerAddrIP && uint64(connection.Laddr.Port) == tcpServerAddrPort && connection.Raddr.Port != 0 {
 			require.Equalf(t, "ESTABLISHED", connection.Status, "expected server connection to be ESTABLISHED, have %+v", connection)
 			serverConnections++
 		}
@@ -454,7 +454,7 @@ func TestConnections(t *testing.T) {
 
 	clientConnections := 0
 	for _, connection := range c {
-		if connection.Raddr.IP == tcpServerAddrIP && connection.Raddr.Port == uint32(tcpServerAddrPort) {
+		if connection.Raddr.IP == tcpServerAddrIP && uint64(connection.Raddr.Port) == tcpServerAddrPort {
 			require.Equalf(t, "ESTABLISHED", connection.Status, "expected client connection to be ESTABLISHED, have %+v", connection)
 			clientConnections++
 		}

process/process_windows.go

@@ -882,7 +882,8 @@ func getFromSnapProcess(pid int32) (int32, int32, string, error) { //nolint:unpa
 	defer windows.CloseHandle(snap)
 	var pe32 windows.ProcessEntry32
 	pe32.Size = uint32(unsafe.Sizeof(pe32))
-	if err = windows.Process32First(snap, &pe32); err != nil {
+	err = windows.Process32First(snap, &pe32)
+	if err != nil {
 		return 0, 0, "", err
 	}
 	for {

sensors/sensors_test.go

@@ -3,7 +3,6 @@
 package sensors
 
 import (
-	"fmt"
 	"os"
 	"testing"
 
@@ -21,7 +20,7 @@ func TestTemperatureStat_String(t *testing.T) {
 		Critical:    0.1,
 	}
 	s := `{"sensorKey":"CPU","temperature":1.1,"sensorHigh":30.1,"sensorCritical":0.1}`
-	assert.Equalf(t, s, fmt.Sprintf("%v", v), "TemperatureStat string is invalid, %v", fmt.Sprintf("%v", v))
+	assert.Equalf(t, s, v.String(), "TemperatureStat string is invalid, %v", v.String())
 }
 
 func TestTemperatures(t *testing.T) {