coder · fuskovic · Aug 4, 2020 · Jul 31, 2020 · Aug 3, 2020 · Aug 4, 2020
diff --git a/command_test.go b/command_test.go
@@ -12,10 +12,14 @@ import (
 var subCmd = new(mockSubCmd)
 
 type (
+	// Mock for root/parent command.
 	mockParentCmd struct{}
-	mockSubCmd    struct {
+	// Mock subcommand with aliases and a nested sucommand of its own.
+	mockSubCmd struct {
 		buf *bytes.Buffer
 	}
+	// Mock subcommand with aliases and no nested subcommands.
+	mockSubCmdNoNested struct{}
 )
 
 func (c *mockParentCmd) Run(fl *pflag.FlagSet) {}
@@ -40,6 +44,10 @@ func (c *mockSubCmd) Run(fl *pflag.FlagSet) {
 	}
 }
 
+func (c *mockSubCmd) Subcommands() []Command {
+	return []Command{new(mockSubCmd)}
+}
+
 func (c *mockSubCmd) WriteString(s string) (int, error) {
 	return c.buf.WriteString(s)
 }
@@ -49,7 +57,18 @@ func (c *mockSubCmd) Spec() CommandSpec {
 		Name:    "mockSubCmd",
 		Usage:   "Test a subcommand.",
 		Aliases: []string{"s", "sc", "sub"},
-		Desc:    "A simple mock subcommand with aliases.",
+		Desc:    "A simple mock subcommand with aliases and its own subcommand.",
+	}
+}
+
+func (c *mockSubCmdNoNested) Run(fl *pflag.FlagSet) {}
+
+func (c *mockSubCmdNoNested) Spec() CommandSpec {
+	return CommandSpec{
+		Name:    "mockSubCmdNoNested",
+		Usage:   "Used for help output tests.",
+		Aliases: []string{"s", "sc", "sub"},
+		Desc:    "A simple mock subcommand with aliases and no nested subcommands.",
 	}
 }
 
@@ -73,19 +92,65 @@ func TestCmdHelpOutput(t *testing.T) {
 	t.Run(t.Name(), func(t *testing.T) {
 		expected := `Usage: mockParentCmd Mock parent command usage.
 
-Mock parent command description.
+Description: Mock parent command description.
 
 Commands:
-	s,sc,sub,mockSubCmd  - A simple mock subcommand with aliases.
+	s, sc, sub, mockSubCmd  - A simple mock subcommand with aliases and its own subcommand.
 `
 		buf := new(bytes.Buffer)
 		cmd := new(mockParentCmd)
 		name := cmd.Spec().Name
 		fl := pflag.NewFlagSet(name, pflag.ExitOnError)
 		// If the help output doesn't contain the subcommand and
 		// isn't formatted the way we expect the test will fail.
-		renderHelp(name, cmd, fl, buf)
-		got := string(buf.Bytes())
+		renderHelp(buf, name, cmd, fl)
+		got := buf.String()
 		assert.Equal(t, t.Name(), expected, got)
 	})
 }
+
+func TestSubCmdHelpOutput(t *testing.T) {
+	withNested := `Usage: mockSubCmd Test a subcommand.
+
+Aliases: s, sc, sub
+
+Description: A simple mock subcommand with aliases and its own subcommand.
+
+Commands:
+	s, sc, sub, mockSubCmd  - A simple mock subcommand with aliases and its own subcommand.
+`
+
+	noNested := `Usage: mockSubCmdNoNested Used for help output tests.
+
+Aliases: s, sc, sub
+
+Description: A simple mock subcommand with aliases and no nested subcommands.
+`
+
+	for _, test := range []struct {
+		name, expected string
+		cmd            Command
+	}{
+		{
+			name:     "subcmd w/nested subcmd.",
+			expected: withNested,
+			cmd:      new(mockSubCmd),
+		},
+		{
+			name:     "subcmd w/no nested subcmds.",
+			expected: noNested,
+			cmd:      new(mockSubCmdNoNested),
+		},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			buf := new(bytes.Buffer)
+			name := test.cmd.Spec().Name
+			fl := pflag.NewFlagSet(name, pflag.ExitOnError)
+			// If the help output is not written to the buffer
+			// in the format we expect then the test will fail.
+			renderHelp(buf, name, test.cmd, fl)
+			got := buf.String()
+			assert.Equal(t, t.Name(), test.expected, got)
+		})
+	}
+}
diff --git a/help.go b/help.go
@@ -45,18 +45,17 @@ func renderFlagHelp(fullName string, fl *pflag.FlagSet, w io.Writer) {
 }
 
 // renderHelp generates a command's help page.
-func renderHelp(fullName string, cmd Command, fl *pflag.FlagSet, w io.Writer) {
+func renderHelp(w io.Writer, fullName string, cmd Command, fl *pflag.FlagSet) {
 	var b strings.Builder
 	spec := cmd.Spec()
 	fmt.Fprintf(&b, "Usage: %v %v\n\n", fullName, spec.Usage)
 
 	// If the command has aliases, add them to the output as a comma-separated list.
 	if spec.HasAliases() {
-		fmt.Fprintf(&b, "Aliases: %v", spec.Aliases)
+		fmt.Fprintf(&b, "Aliases: %s\n\n", strings.Join(spec.Aliases, ", "))
 	}
-	// Render usage and description.
-	usageAndDesc := fmt.Sprintf("%s%s\n", b.String(), spec.Desc)
-	fmt.Fprint(w, usageAndDesc)
+	// Print usage and description.
+	fmt.Fprintf(w, "%sDescription: %s\n", b.String(), spec.Desc)
 
 	tw := tabwriter.NewWriter(w, 0, 4, 2, ' ', tabwriter.StripEscape)
 	defer tw.Flush()
@@ -80,7 +79,7 @@ func renderHelp(fullName string, cmd Command, fl *pflag.FlagSet, w io.Writer) {
 				continue
 			}
 
-			allNames := strings.Join(append(spec.Aliases, spec.Name), ",")
+			allNames := strings.Join(append(spec.Aliases, spec.Name), ", ")
 
 			fmt.Fprintf(tw,
 				tabEscape+"\t"+tabEscape+"%v\t- %v\n",

diff --git a/run.go b/run.go
@@ -94,7 +94,7 @@ func Run(cmd Command, args []string, parent string) {
 	// Reassign the usage now that we've parsed the args
 	// so that we can render it manually.
 	fl.Usage = func() {
-		renderHelp(name, cmd, fl, os.Stderr)
+		renderHelp(os.Stderr, name, cmd, fl)
 	}
 	if err != nil {
 		fl.Usage()