cli-plugins: minor cleanups: use Println

- use Println to print newline instead of custom format
- suppress some errors to make my IDE and linters happier
- use res.Assert() with icmd.Expected{} where possible to make
  assertions not depend on newline / whitespace randomness
- use apiClient instead of client for the API client to
  prevent shadowing imports.
- use dockerCLI with Go's standard camelCase casing.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli-plugins/examples/helloworld/main.go

@@ -12,24 +12,24 @@ import (
 )
 
 func main() {
-	plugin.Run(func(dockerCli command.Cli) *cobra.Command {
+	plugin.Run(func(dockerCLI command.Cli) *cobra.Command {
 		goodbye := &cobra.Command{
 			Use:   "goodbye",
 			Short: "Say Goodbye instead of Hello",
 			Run: func(cmd *cobra.Command, _ []string) {
-				fmt.Fprintln(dockerCli.Out(), "Goodbye World!")
+				_, _ = fmt.Fprintln(dockerCLI.Out(), "Goodbye World!")
 			},
 		}
 		apiversion := &cobra.Command{
 			Use:   "apiversion",
 			Short: "Print the API version of the server",
 			RunE: func(_ *cobra.Command, _ []string) error {
-				cli := dockerCli.Client()
-				ping, err := cli.Ping(context.Background())
+				apiClient := dockerCLI.Client()
+				ping, err := apiClient.Ping(context.Background())
 				if err != nil {
 					return err
 				}
-				fmt.Println(ping.APIVersion)
+				_, _ = fmt.Println(ping.APIVersion)
 				return nil
 			},
 		}
@@ -38,7 +38,7 @@ func main() {
 			Use:   "exitstatus2",
 			Short: "Exit with status 2",
 			RunE: func(_ *cobra.Command, _ []string) error {
-				fmt.Fprintln(dockerCli.Err(), "Exiting with error status 2")
+				_, _ = fmt.Fprintln(dockerCLI.Err(), "Exiting with error status 2")
 				os.Exit(2)
 				return nil
 			},
@@ -56,33 +56,33 @@ func main() {
 					return err
 				}
 				if preRun {
-					fmt.Fprintf(dockerCli.Err(), "Plugin PersistentPreRunE called")
+					_, _ = fmt.Fprintln(dockerCLI.Err(), "Plugin PersistentPreRunE called")
 				}
 				return nil
 			},
 			RunE: func(cmd *cobra.Command, args []string) error {
 				if debug {
-					fmt.Fprintf(dockerCli.Err(), "Plugin debug mode enabled")
+					_, _ = fmt.Fprintln(dockerCLI.Err(), "Plugin debug mode enabled")
 				}
 
 				switch optContext {
 				case "Christmas":
-					fmt.Fprintf(dockerCli.Out(), "Merry Christmas!\n")
+					_, _ = fmt.Fprintln(dockerCLI.Out(), "Merry Christmas!")
 					return nil
 				case "":
 					// nothing
 				}
 
 				if who == "" {
-					who, _ = dockerCli.ConfigFile().PluginConfig("helloworld", "who")
+					who, _ = dockerCLI.ConfigFile().PluginConfig("helloworld", "who")
 				}
 				if who == "" {
 					who = "World"
 				}
 
-				fmt.Fprintf(dockerCli.Out(), "Hello %s!\n", who)
-				dockerCli.ConfigFile().SetPluginConfig("helloworld", "lastwho", who)
-				return dockerCli.ConfigFile().Save()
+				_, _ = fmt.Fprintln(dockerCLI.Out(), "Hello", who)
+				dockerCLI.ConfigFile().SetPluginConfig("helloworld", "lastwho", who)
+				return dockerCLI.ConfigFile().Save()
 			},
 		}
 

cli-plugins/hooks/printer.go

@@ -11,8 +11,8 @@ func PrintNextSteps(out io.Writer, messages []string) {
 	if len(messages) == 0 {
 		return
 	}
-	fmt.Fprintln(out, aec.Bold.Apply("\nWhat's next:"))
+	_, _ = fmt.Fprintln(out, aec.Bold.Apply("\nWhat's next:"))
 	for _, n := range messages {
-		_, _ = fmt.Fprintf(out, "    %s\n", n)
+		_, _ = fmt.Fprintln(out, "   ", n)
 	}
 }

e2e/cli-plugins/config_test.go

@@ -20,7 +20,7 @@ func TestConfig(t *testing.T) {
 	res := icmd.RunCmd(run("helloworld"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
-		Out:      "Hello Cambridge!",
+		Out:      "Hello Cambridge",
 	})
 
 	cfg2, err := config.Load(filepath.Dir(cfg.GetFilename()))

e2e/cli-plugins/dial_test.go

@@ -6,8 +6,6 @@ import (
 	"testing"
 
 	"github.com/docker/cli/cli-plugins/manager"
-	"gotest.tools/v3/assert"
-	is "gotest.tools/v3/assert/cmp"
 	"gotest.tools/v3/icmd"
 )
 
@@ -24,7 +22,9 @@ func TestCLIPluginDialStdio(t *testing.T) {
 	helloworld := filepath.Join(os.Getenv("DOCKER_CLI_E2E_PLUGINS_EXTRA_DIRS"), "docker-helloworld")
 	cmd := icmd.Command(helloworld, "--config=blah", "--log-level", "debug", "helloworld", "--who=foo")
 	res := icmd.RunCmd(cmd, icmd.WithEnv(manager.ReexecEnvvar+"=/bin/true"))
-	res.Assert(t, icmd.Success)
-	assert.Assert(t, is.Contains(res.Stderr(), `msg="commandconn: starting /bin/true with [--config=blah --log-level debug system dial-stdio]"`))
-	assert.Assert(t, is.Equal(res.Stdout(), "Hello foo!\n"))
+	res.Assert(t, icmd.Expected{
+		ExitCode: 0,
+		Err:      `msg="commandconn: starting /bin/true with [--config=blah --log-level debug system dial-stdio]"`,
+		Out:      `Hello foo`,
+	})
 }

e2e/cli-plugins/flags_test.go

@@ -15,7 +15,7 @@ func TestRunGoodArgument(t *testing.T) {
 	res := icmd.RunCmd(run("helloworld", "--who", "Cleveland"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
-		Out:      "Hello Cleveland!",
+		Out:      "Hello Cleveland",
 	})
 }
 
@@ -33,25 +33,25 @@ func TestClashWithGlobalArgs(t *testing.T) {
 		{
 			name:        "short-without-val",
 			args:        []string{"-D"},
-			expectedOut: "Hello World!",
+			expectedOut: "Hello World",
 			expectedErr: "Plugin debug mode enabled",
 		},
 		{
 			name:        "long-without-val",
 			args:        []string{"--debug"},
-			expectedOut: "Hello World!",
+			expectedOut: "Hello World",
 			expectedErr: "Plugin debug mode enabled",
 		},
 		{
 			name:        "short-with-val",
 			args:        []string{"-c", "Christmas"},
-			expectedOut: "Merry Christmas!",
+			expectedOut: "Merry Christmas",
 			expectedErr: icmd.None,
 		},
 		{
 			name:        "short-with-val",
 			args:        []string{"--context", "Christmas"},
-			expectedOut: "Merry Christmas!",
+			expectedOut: "Merry Christmas",
 			expectedErr: icmd.None,
 		},
 	} {
@@ -220,7 +220,7 @@ func TestCliPluginsVersion(t *testing.T) {
 			name:    "plugin-with-version",
 			args:    []string{"helloworld", "version"},
 			expCode: 0,
-			expOut:  "Hello World!",
+			expOut:  "Hello World",
 			expErr:  icmd.None,
 		},
 		{

e2e/cli-plugins/plugins/presocket/main.go

@@ -113,7 +113,7 @@ func RootCmd(dockerCli command.Cli) *cobra.Command {
 			select {
 			case <-done:
 			case <-time.After(2 * time.Second):
-				_, _ = fmt.Fprint(dockerCli.Err(), "timeout after 2 seconds")
+				_, _ = fmt.Fprintln(dockerCli.Err(), "timeout after 2 seconds")
 			}
 			return nil
 		},

e2e/cli-plugins/run_test.go

@@ -4,7 +4,6 @@ import (
 	"testing"
 
 	"gotest.tools/v3/assert"
-	is "gotest.tools/v3/assert/cmp"
 	"gotest.tools/v3/golden"
 	"gotest.tools/v3/icmd"
 )
@@ -123,7 +122,7 @@ func TestRunGood(t *testing.T) {
 	res := icmd.RunCmd(run("helloworld"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
-		Out:      "Hello World!",
+		Out:      "Hello World",
 		Err:      icmd.None,
 	})
 }
@@ -218,18 +217,23 @@ func TestCliInitialized(t *testing.T) {
 	run, _, cleanup := prepare(t)
 	defer cleanup()
 
-	var apiversion string
+	var apiVersion string
 	t.Run("withhook", func(t *testing.T) {
 		res := icmd.RunCmd(run("helloworld", "--pre-run", "apiversion"))
-		res.Assert(t, icmd.Success)
-		assert.Assert(t, res.Stdout() != "")
-		apiversion = res.Stdout()
-		assert.Assert(t, is.Equal(res.Stderr(), "Plugin PersistentPreRunE called"))
+		res.Assert(t, icmd.Expected{
+			ExitCode: 0,
+			Err:      "Plugin PersistentPreRunE called",
+		})
+		apiVersion = res.Stdout()
+		assert.Assert(t, apiVersion != "")
 	})
 	t.Run("withouthook", func(t *testing.T) {
 		res := icmd.RunCmd(run("nopersistentprerun"))
-		res.Assert(t, icmd.Success)
-		assert.Assert(t, is.Equal(res.Stdout(), apiversion))
+		res.Assert(t, icmd.Expected{
+			ExitCode: 0,
+			Err:      icmd.None,
+			Out:      apiVersion,
+		})
 	})
 }