fortify: test help message

This helps catch regressions in "command".

Signed-off-by: Ophestra <cat@gensokyo.uk>

main.go

@@ -5,6 +5,7 @@ import (
 	_ "embed"
 	"errors"
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"os/signal"
@@ -52,11 +53,38 @@ func main() {
 		log.Fatal("this program must not run as root")
 	}
 
+	err := buildCommand(os.Stderr).Parse(os.Args[1:])
+	if errors.Is(err, errSuccess) || errors.Is(err, command.ErrHelp) {
+		internal.Exit(0)
+		panic("unreachable")
+	}
+	if errors.Is(err, command.ErrNoMatch) || errors.Is(err, command.ErrEmptyTree) {
+		internal.Exit(1)
+		panic("unreachable")
+	}
+	if err == nil {
+		log.Fatal("unreachable")
+	}
+
+	var flagError command.FlagError
+	if !errors.As(err, &flagError) {
+		log.Printf("command: %v", err)
+		internal.Exit(1)
+		panic("unreachable")
+	}
+	fmsg.Verbose(flagError.Error())
+	if flagError.Success() {
+		internal.Exit(0)
+	}
+	internal.Exit(1)
+}
+
+func buildCommand(out io.Writer) command.Command {
 	var (
 		flagVerbose bool
 		flagJSON    bool
 	)
-	c := command.New(os.Stderr, log.Printf, "fortify", func([]string) error { fmsg.Store(flagVerbose); return nil }).
+	c := command.New(out, log.Printf, "fortify", func([]string) error { fmsg.Store(flagVerbose); return nil }).
 		Flag(&flagVerbose, "v", command.BoolFlag(false), "Print debug messages to the console").
 		Flag(&flagJSON, "json", command.BoolFlag(false), "Serialise output as JSON when applicable")
 
@@ -264,30 +292,7 @@ func main() {
 	c.Command("shim", command.UsageInternal, func([]string) error { shim.Main(); return errSuccess })
 	c.Command("init", command.UsageInternal, func([]string) error { init0.Main(); return errSuccess })
 
-	err := c.Parse(os.Args[1:])
-	if errors.Is(err, errSuccess) || errors.Is(err, command.ErrHelp) {
-		internal.Exit(0)
-		panic("unreachable")
-	}
-	if errors.Is(err, command.ErrNoMatch) || errors.Is(err, command.ErrEmptyTree) {
-		internal.Exit(1)
-		panic("unreachable")
-	}
-	if err == nil {
-		log.Fatal("unreachable")
-	}
-
-	var flagError command.FlagError
-	if !errors.As(err, &flagError) {
-		log.Printf("command: %v", err)
-		internal.Exit(1)
-		panic("unreachable")
-	}
-	fmsg.Verbose(flagError.Error())
-	if flagError.Success() {
-		internal.Exit(0)
-	}
-	internal.Exit(1)
+	return c
 }
 
 func runApp(a fst.App, config *fst.Config) {

main_test.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"bytes"
+	"errors"
+	"flag"
+	"testing"
+
+	"git.gensokyo.uk/security/fortify/command"
+)
+
+func TestHelp(t *testing.T) {
+	testCases := []struct {
+		name string
+		args []string
+		want string
+	}{
+		{
+			"main", []string{}, `
+Usage:	fortify [-h | --help] [-v] [--json] COMMAND [OPTIONS]
+
+Commands:
+    app         Launch app defined by the specified config file
+    run         Configure and start a permissive default sandbox
+    show        Show the contents of an app configuration
+    ps          List active apps and their state
+    version     Show fortify version
+    license     Show full license text
+    template    Produce a config template
+    help        Show this help message
+
+`,
+		},
+		{
+			"run", []string{"run", "-h"}, `
+Usage:	fortify run [-h | --help] [--dbus-config <value>] [--dbus-system <value>] [--mpris] [--dbus-log] [--id <value>] [-a <int>] [-g <value>] [-d <value>] [-u <value>] [--wayland] [-X] [--dbus] [--pulse] COMMAND [OPTIONS]
+
+Flags:
+  -X	Share X11 socket and allow connection
+  -a int
+    	Fortify application ID
+  -d string
+    	Application home directory (default "os")
+  -dbus
+    	Proxy D-Bus connection
+  -dbus-config string
+    	Path to D-Bus proxy config file, or "builtin" for defaults (default "builtin")
+  -dbus-log
+    	Force logging in the D-Bus proxy
+  -dbus-system string
+    	Path to system D-Bus proxy config file, or "nil" to disable (default "nil")
+  -g value
+    	Groups inherited by the app process
+  -id string
+    	App ID, leave empty to disable security context app_id
+  -mpris
+    	Allow owning MPRIS D-Bus path, has no effect if custom config is available
+  -pulse
+    	Share PulseAudio socket and cookie
+  -u string
+    	Passwd name within sandbox (default "chronos")
+  -wayland
+    	Allow Wayland connections
+
+`,
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			out := new(bytes.Buffer)
+			c := buildCommand(out)
+			if err := c.Parse(tc.args); !errors.Is(err, command.ErrHelp) && !errors.Is(err, flag.ErrHelp) {
+				t.Errorf("Parse: error = %v; want %v",
+					err, command.ErrHelp)
+			}
+			if got := out.String(); got != tc.want {
+				t.Errorf("Parse: %s want %s", got, tc.want)
+			}
+		})
+	}
+}