From 7cd2f5b30fa2b738c52db3c76c256cb261b55f21 Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Tue, 5 Jul 2022 13:25:49 +0300
Subject: [PATCH] [system] Improve tests

---
 system/info_fs_linux.go   |  3 ++-
 system/info_linux_test.go | 15 ++++++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/system/info_fs_linux.go b/system/info_fs_linux.go
index 790918cc..226bca69 100644
--- a/system/info_fs_linux.go
+++ b/system/info_fs_linux.go
@@ -85,7 +85,7 @@ func CalculateIOUtil(io1, io2 map[string]*IOStats, duration time.Duration) map[s
 	itv := uint64(duration / (time.Millisecond * 10))
 
 	for device := range io1 {
-		if io1[device] == nil || io2[device] == nil {
+		if io2[device] == nil {
 			continue
 		}
 
@@ -118,6 +118,7 @@ func parseIOStats(s *bufio.Scanner) (map[string]*IOStats, error) {
 		device := strutil.ReadField(text, 2, true)
 
 		if len(device) > 3 {
+			// Skip devices with names like ram* and loop*
 			if device[:3] == "ram" || device[:3] == "loo" {
 				continue
 			}
diff --git a/system/info_linux_test.go b/system/info_linux_test.go
index d34ca243..66ac4b63 100644
--- a/system/info_linux_test.go
+++ b/system/info_linux_test.go
@@ -8,6 +8,7 @@ package system
 // ////////////////////////////////////////////////////////////////////////////////// //
 
 import (
+	"bufio"
 	"io/ioutil"
 	"os"
 	"strconv"
@@ -448,14 +449,22 @@ func (s *SystemSuite) TestFSUsage(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(fs, NotNil)
 
+	c.Assert(CalculateIOUtil(nil, nil, time.Minute), IsNil)
+
 	util = CalculateIOUtil(
-		map[string]*IOStats{"abc": {IOMs: 10}},
-		map[string]*IOStats{"abc": {IOMs: 1840}},
+		map[string]*IOStats{"1": {IOMs: 10}, "2": {IOMs: 1}, "3": {IOMs: 11}},
+		map[string]*IOStats{"1": {IOMs: 1840}, "2": {IOMs: 10000000}},
 		time.Minute,
 	)
 
 	c.Assert(util, NotNil)
-	c.Assert(util["abc"], Equals, 3.05)
+	c.Assert(util["1"], Equals, 3.05)
+
+	bs := bufio.NewScanner(strings.NewReader(" 11       0 vda 0 0 0 0 0 0 0 0 0 0 0\n 1       0 ram0 0 0 0 0 0 0 0 0 0 0 0\n  7       0 loop0 0 0 0 0 0 0 0 0 0 0 0\n"))
+	st, err := parseIOStats(bs)
+
+	c.Assert(err, IsNil)
+	c.Assert(st, HasLen, 1)
 
 	procDiskStatsFile = origProcDiskStatsFile
 	procStatFile = origProcStatFile