update integration-cli/docker_cli_stats_test.go use Assert statement

part of #16756

Signed-off-by: Xiaoxu Chen <chenxiaoxu14@otcaix.iscas.ac.cn>

integration-cli/docker_cli_stats_test.go

@@ -1,11 +1,11 @@
 package main
 
 import (
-	"bytes"
 	"os/exec"
 	"strings"
 	"time"
 
+	"github.com/docker/docker/pkg/integration/checker"
 	"github.com/go-check/check"
 )
 
@@ -13,7 +13,7 @@ func (s *DockerSuite) TestStatsNoStream(c *check.C) {
 	testRequires(c, DaemonIsLinux)
 	out, _ := dockerCmd(c, "run", "-d", "busybox", "top")
 	id := strings.TrimSpace(out)
-	c.Assert(waitRun(id), check.IsNil)
+	c.Assert(waitRun(id), checker.IsNil)
 
 	statsCmd := exec.Command(dockerBinary, "stats", "--no-stream", id)
 	type output struct {
@@ -29,12 +29,8 @@ func (s *DockerSuite) TestStatsNoStream(c *check.C) {
 
 	select {
 	case outerr := <-ch:
-		if outerr.err != nil {
-			c.Fatalf("Error running stats: %v", outerr.err)
-		}
-		if !bytes.Contains(outerr.out, []byte(id)) {
-			c.Fatalf("running container wasn't present in output")
-		}
+		c.Assert(outerr.err, checker.IsNil, check.Commentf("Error running stats: %v", outerr.err))
+		c.Assert(string(outerr.out), checker.Contains, id) //running container wasn't present in output
 	case <-time.After(3 * time.Second):
 		statsCmd.Process.Kill()
 		c.Fatalf("stats did not return immediately when not streaming")
@@ -45,14 +41,10 @@ func (s *DockerSuite) TestStatsContainerNotFound(c *check.C) {
 	testRequires(c, DaemonIsLinux)
 
 	out, _, err := dockerCmdWithError("stats", "notfound")
-	c.Assert(err, check.NotNil)
-	if !strings.Contains(out, "no such id: notfound") {
-		c.Fatalf("Expected to fail on not found container stats, got %q instead", out)
-	}
+	c.Assert(err, checker.NotNil)
+	c.Assert(out, checker.Contains, "no such id: notfound", check.Commentf("Expected to fail on not found container stats, got %q instead", out))
 
 	out, _, err = dockerCmdWithError("stats", "--no-stream", "notfound")
-	c.Assert(err, check.NotNil)
-	if !strings.Contains(out, "no such id: notfound") {
-		c.Fatalf("Expected to fail on not found container stats with --no-stream, got %q instead", out)
-	}
+	c.Assert(err, checker.NotNil)
+	c.Assert(out, checker.Contains, "no such id: notfound", check.Commentf("Expected to fail on not found container stats with --no-stream, got %q instead", out))
 }