added test to serverLs, edded config to tabwriter

cmd/server.go

@@ -61,7 +61,8 @@ be displayed and one can be selected.
 				Name:  "ls",
 				Usage: "List all servers",
 				Action: func(ctx *cli.Context) error {
-					return serverLs(ctx, cfg)
+					format := ctx.String("format")
+					return serverLs(ctx.App.Writer, cfg, format)
 				},
 			},
 			{
@@ -118,12 +119,17 @@ func serverDelete(cfg *config.Config, serverName string) error {
 }
 
 // serverLs command to list rancher servers from the local config
-func serverLs(ctx *cli.Context, cfg *config.Config) error {
-	writer := NewTableWriter([][]string{
+func serverLs(out io.Writer, cfg *config.Config, format string) error {
+	writerConfig := &TableWriterConfig{
+		Writer: out,
+		Format: format,
+	}
+
+	writer := NewTableWriterWithConfig([][]string{
 		{"CURRENT", "Current"},
 		{"NAME", "Name"},
 		{"URL", "URL"},
-	}, ctx)
+	}, writerConfig)
 
 	defer writer.Close()
 

cmd/server_test.go

@@ -177,6 +177,93 @@ func TestServerSwitch(t *testing.T) {
 	}
 }
 
+func TestServerLs(t *testing.T) {
+	tt := []struct {
+		name           string
+		config         *config.Config
+		format         string
+		expectedOutput string
+		expectedErr    bool
+	}{
+		{
+			name: "list servers",
+			expectedOutput: `CURRENT   NAME      URL
+*         server1   https://myserver-1.com
+          server2   https://myserver-2.com
+          server3   https://myserver-3.com
+`,
+		},
+		{
+			name:           "list empty config",
+			config:         &config.Config{},
+			format:         "",
+			expectedOutput: "CURRENT   NAME      URL\n",
+		},
+		{
+			name:   "list servers with json format",
+			format: "json",
+			expectedOutput: `{"Index":1,"Current":"*","Name":"server1","URL":"https://myserver-1.com"}
+{"Index":2,"Current":"","Name":"server2","URL":"https://myserver-2.com"}
+{"Index":3,"Current":"","Name":"server3","URL":"https://myserver-3.com"}
+`,
+		},
+		{
+			name:   "list servers with yaml format",
+			format: "yaml",
+			expectedOutput: `Current: '*'
+Index: 1
+Name: server1
+URL: https://myserver-1.com
+
+Current: ""
+Index: 2
+Name: server2
+URL: https://myserver-2.com
+
+Current: ""
+Index: 3
+Name: server3
+URL: https://myserver-3.com
+
+`,
+		},
+		{
+			name:   "list servers with custom format",
+			format: "{{.URL}}",
+			expectedOutput: `https://myserver-1.com
+https://myserver-2.com
+https://myserver-3.com
+`,
+		},
+		{
+			name:        "list servers with custom format",
+			format:      "{{.err}}",
+			expectedErr: true,
+		},
+	}
+	for _, tc := range tt {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			out := &bytes.Buffer{}
+
+			if tc.config == nil {
+				tc.config = newTestConfig()
+			}
+
+			// do test and check resulting config
+			err := serverLs(out, tc.config, tc.format)
+			if tc.expectedErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+			}
+
+			assert.Equal(t, tc.expectedOutput, out.String())
+		})
+	}
+}
+
 func newTestConfig() *config.Config {
 	return &config.Config{
 		CurrentServer: "server1",

cmd/writer.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"encoding/json"
+	"io"
 	"os"
 	"text/tabwriter"
 
@@ -18,27 +19,52 @@ type TableWriter struct {
 	Writer        *tabwriter.Writer
 }
 
+type TableWriterConfig struct {
+	Quiet  bool
+	Format string
+	Writer io.Writer
+}
+
 func NewTableWriter(values [][]string, ctx *cli.Context) *TableWriter {
+	cfg := &TableWriterConfig{
+		Writer: os.Stdout,
+		Quiet:  ctx.Bool("quiet"),
+		Format: ctx.String("format"),
+	}
+
+	return NewTableWriterWithConfig(values, cfg)
+}
+
+func NewTableWriterWithConfig(values [][]string, config *TableWriterConfig) *TableWriter {
+	writer := config.Writer
+	if writer == nil {
+		writer = os.Stdout
+	}
+
 	t := &TableWriter{
-		Writer: tabwriter.NewWriter(os.Stdout, 10, 1, 3, ' ', 0),
+		Writer: tabwriter.NewWriter(writer, 10, 1, 3, ' ', 0),
 	}
 	t.HeaderFormat, t.ValueFormat = SimpleFormat(values)
 
-	if ctx.Bool("quiet") {
+	// remove headers if quiet or with a different format
+	if config.Quiet || config.Format != "" {
 		t.HeaderFormat = ""
+	}
+
+	// when quiet show only the ID
+	if config.Quiet {
 		t.ValueFormat = "{{.ID}}\n"
 	}
 
-	customFormat := ctx.String("format")
-	if customFormat == "json" {
-		t.HeaderFormat = ""
-		t.ValueFormat = "json"
-	} else if customFormat == "yaml" {
-		t.HeaderFormat = ""
-		t.ValueFormat = "yaml"
-	} else if customFormat != "" {
-		t.ValueFormat = customFormat + "\n"
-		t.HeaderFormat = ""
+	// check for custom formatting
+	if config.Format != "" {
+		customFormat := config.Format
+
+		// add a newline for other custom formats
+		if customFormat != "json" && customFormat != "yaml" {
+			customFormat += "\n"
+		}
+		t.ValueFormat = customFormat
 	}
 
 	return t