add specs for process scanner

internal/psscanner/proclist.go

@@ -64,7 +64,7 @@ func getPIDs() ([]int, error) {
 		if f.IsDir() {
 			name := f.Name()
 			pid, err := strconv.Atoi(name)
-			if err != nil {
+			if err != nil || pid <= 0 {
 				continue // not a pid
 			}
 			pids = append(pids, pid)

internal/psscanner/proclist_test.go

@@ -1,10 +1,17 @@
 package psscanner
 
 import (
+	"encoding/hex"
+	"errors"
 	"fmt"
+	"os"
+	"reflect"
 	"testing"
+	"time"
 )
 
+// GetCmd
+
 func TestGetCmd(t *testing.T) {
 	tests := []struct {
 		pid     int
@@ -14,6 +21,9 @@ func TestGetCmd(t *testing.T) {
 		err     string
 	}{
 		{pid: 1, cmdLine: []byte("abc"), cmdErr: nil, cmd: "abc", err: ""},
+		{pid: 1, cmdLine: []byte(""), cmdErr: nil, cmd: "", err: ""},                                                 // can work with empty result
+		{pid: 1, cmdLine: []byte("abc\x00123"), cmdErr: nil, cmd: "abc 123", err: ""},                                // turns null bytes into spaces
+		{pid: 1, cmdLine: []byte("abc"), cmdErr: errors.New("file-system-error"), cmd: "", err: "file-system-error"}, // returns error from file reader
 	}
 
 	for _, tt := range tests {
@@ -38,3 +48,126 @@ func mockCmdLineReader(cmdLine []byte, err error) (restore func()) {
 		cmdLineReader = oldFunc
 	}
 }
+
+// GetPIDs
+
+func TestGetPIDs(t *testing.T) {
+	tests := []struct {
+		proc    []os.FileInfo
+		procErr error
+		pids    []int
+		err     string
+	}{
+		{proc: []os.FileInfo{newMockDir("42"), newMockDir("somedir")}, procErr: nil, pids: []int{42}, err: ""},                   // reads numbers and ignores everything else
+		{proc: []os.FileInfo{newMockDir("42"), newMockFile("13")}, procErr: nil, pids: []int{42}, err: ""},                       // reads directories and ignores files
+		{proc: []os.FileInfo{newMockDir("0"), newMockDir("-1")}, procErr: nil, pids: []int{}, err: ""},                           // ignores 0 and negative numbers
+		{proc: []os.FileInfo{}, procErr: nil, pids: []int{}, err: ""},                                                            // can handle empty procfs
+		{proc: []os.FileInfo{}, procErr: errors.New("file-system-error"), pids: nil, err: "opening proc dir: file-system-error"}, // returns errors
+	}
+
+	for _, tt := range tests {
+		restore := mockProcDirReader(tt.proc, tt.procErr)
+		pids, err := getPIDs()
+		if !reflect.DeepEqual(pids, tt.pids) {
+			t.Errorf("Wrong pids returned: got %v but want %v", pids, tt.pids)
+		}
+		if (err != nil || tt.err != "") && fmt.Sprintf("%v", err) != tt.err {
+			t.Errorf("Wrong error returned: got %v but want %s", err, tt.err)
+		}
+		restore()
+	}
+}
+
+func mockProcDirReader(proc []os.FileInfo, err error) (restore func()) {
+	oldFunc := procDirReader
+	procDirReader = func() ([]os.FileInfo, error) {
+		return proc, err
+	}
+	return func() {
+		procDirReader = oldFunc
+	}
+}
+
+func newMockDir(name string) *mockFileInfo {
+	return &mockFileInfo{
+		name:  name,
+		isDir: true,
+	}
+}
+
+func newMockFile(name string) *mockFileInfo {
+	return &mockFileInfo{
+		name:  name,
+		isDir: false,
+	}
+}
+
+type mockFileInfo struct {
+	name  string
+	isDir bool
+}
+
+func (f *mockFileInfo) Name() string {
+	return f.name
+}
+func (f *mockFileInfo) Size() int64 {
+	return 0
+}
+func (f *mockFileInfo) Mode() os.FileMode {
+	return 0
+}
+func (f *mockFileInfo) ModTime() time.Time {
+	return time.Now()
+}
+func (f *mockFileInfo) IsDir() bool {
+	return f.isDir
+}
+func (f *mockFileInfo) Sys() interface{} {
+	return nil
+}
+
+// GetUID
+
+func TestGetUID(t *testing.T) {
+	completeStatus, _ := hex.DecodeString("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")
+	uidLineBroken, _ := hex.DecodeString("4e616d653a0963726f6e0a556d61736b3a09303032320a53746174653a09532028736c656570696e67290a546769643a09370a4e6769643a09300a5069643a09370a505069643a09350a5472616365725069643a09300a5569643a")
+	notEnoughLines, _ := hex.DecodeString("4e616d653a0963726f6e0a556d61736b3a09303032320a537461")
+	tests := []struct {
+		pid     int
+		stat    []byte
+		statErr error
+		uid     string
+		err     string
+	}{
+		{pid: 7, stat: completeStatus, statErr: nil, uid: "0", err: ""},                                         // can read normal stat
+		{pid: 7, stat: uidLineBroken, statErr: nil, uid: "", err: "uid line read incomplete"},                   // errors on incomplete Uid line
+		{pid: 7, stat: notEnoughLines, statErr: nil, uid: "", err: "no uid information"},                        // errors for insufficient lines
+		{pid: 7, stat: []byte(""), statErr: nil, uid: "", err: "no uid information"},                            // errors for insufficient lines
+		{pid: 7, stat: []byte(""), statErr: errors.New("file-system-error"), uid: "", err: "file-system-error"}, // returns file system errors
+	}
+
+	for _, tt := range tests {
+		restore := mockProcStatusReader(tt.stat, tt.statErr)
+		uid, err := getUID(tt.pid)
+		if uid != tt.uid {
+			fmt.Printf("STAT: %s", tt.stat)
+			t.Errorf("Wrong uid returned: got %s but want %s", uid, tt.uid)
+		}
+		if (err != nil || tt.err != "") && fmt.Sprintf("%v", err) != tt.err {
+			t.Errorf("Wrong error returned: got %v but want %s", err, tt.err)
+		}
+		restore()
+	}
+}
+
+func mockProcStatusReader(stat []byte, err error) (restore func()) {
+	oldFunc := procStatusReader
+	procStatusReader = func(pid int) ([]byte, error) {
+		return stat, err
+	}
+	return func() {
+		procStatusReader = oldFunc
+	}
+}
+
+// refresh