fix(cli): show help when no argument is passed (#628)

* Fix subcommands help

* refactor: call ShowAppHelpAndExit

* refactor: remove an unused error

* test: remove exit cases

Co-authored-by: knqyf263 <knqyf263@gmail.com>

internal/artifact/config/config.go

@@ -57,8 +57,7 @@ func (c *Config) Init(image bool) error {
 		return nil
 	}
 
-	if err := c.ArtifactConfig.Init(c.Context.Args(), c.Logger); err != nil {
+	if err := c.ArtifactConfig.Init(c.Context, c.Logger); err != nil {
-		cli.ShowAppHelp(c.Context)
 		return err
 	}
 

internal/artifact/config/config_test.go

@@ -184,10 +184,6 @@ func TestConfig_Init(t *testing.T) {
 			},
 			wantErr: "arguments error",
 		},
-		{
-			name:    "sad: no image name",
-			wantErr: "no target is specified",
-		},
 		{
 			name:    "sad: invalid image name",
 			args:    []string{`!"#$%&'()`},

internal/artifact/image.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/aquasecurity/fanal/cache"
 	"github.com/aquasecurity/trivy/internal/artifact/config"
-	artifact "github.com/aquasecurity/trivy/internal/config"
 	"github.com/aquasecurity/trivy/pkg/scanner"
 )
 
@@ -38,10 +37,7 @@ func ImageRun(cliCtx *cli.Context) error {
 	}
 
 	// initialize config
-	err = c.Init(true)
+	if err := c.Init(true); err != nil {
-	if xerrors.Is(err, artifact.ErrNoTarget) {
-		return nil
-	} else if err != nil {
 		return xerrors.Errorf("failed to initialize options: %w", err)
 	}
 

internal/client/config/config.go

@@ -60,12 +60,11 @@ func (c *Config) Init() (err error) {
 		return err
 	}
 
-	if err := c.ArtifactConfig.Init(c.Context.Args(), c.Logger); err != nil {
+	if err := c.ArtifactConfig.Init(c.Context, c.Logger); err != nil {
 		return err
 	}
 
 	if err := c.ImageConfig.Init(c.Context.Args(), c.Logger); err != nil {
-		cli.ShowAppHelp(c.Context)
 		return err
 	}
 

internal/client/config/config_test.go

@@ -224,10 +224,6 @@ func TestConfig_Init(t *testing.T) {
 			},
 			wantErr: "arguments error",
 		},
-		{
-			name:    "sad: no image name",
-			wantErr: "no target is specified",
-		},
 		{
 			name:    "sad: invalid image name",
 			args:    []string{`!"#$%&'()`},

internal/config/artifact.go

@@ -33,19 +33,17 @@ func NewArtifactConfig(c *cli.Context) ArtifactConfig {
 	}
 }
 
-var ErrNoTarget = xerrors.New("no target is specified")
+func (c *ArtifactConfig) Init(ctx *cli.Context, logger *zap.SugaredLogger) (err error) {
-
+	if c.Input == "" && ctx.Args().Len() == 0 {
-func (c *ArtifactConfig) Init(args cli.Args, logger *zap.SugaredLogger) (err error) {
-	if c.Input == "" && args.Len() == 0 {
 		logger.Debug(`trivy requires at least 1 argument or --input option`)
-		return ErrNoTarget
+		cli.ShowAppHelpAndExit(ctx, 0)
-	} else if args.Len() > 1 {
+	} else if ctx.Args().Len() > 1 {
 		logger.Error(`multiple targets cannot be specified`)
 		return xerrors.New("arguments error")
 	}
 
 	if c.Input == "" {
-		c.Target = args.First()
+		c.Target = ctx.Args().First()
 	}
 
 	if c.skipDirectories != "" {

internal/config/artifact_test.go

@@ -35,13 +35,6 @@ func TestArtifactConfig_Init(t *testing.T) {
 			},
 			wantErr: "arguments error",
 		},
-		{
-			name: "sad: no image name",
-			logs: []string{
-				"trivy requires at least 1 argument or --input option",
-			},
-			wantErr: "no target is specified",
-		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -55,7 +48,7 @@ func TestArtifactConfig_Init(t *testing.T) {
 
 			c := config.NewArtifactConfig(ctx)
 
-			err := c.Init(ctx.Args(), logger.Sugar())
+			err := c.Init(ctx, logger.Sugar())
 
 			// tests log messages
 			var gotMessages []string