cli: adds version command (#950)

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>

cmd/wazero/wazero.go

@@ -14,6 +14,7 @@ import (
 	"github.com/tetratelabs/wazero"
 	"github.com/tetratelabs/wazero/experimental"
 	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
+	"github.com/tetratelabs/wazero/internal/version"
 	"github.com/tetratelabs/wazero/sys"
 )
 
@@ -47,6 +48,9 @@ func doMain(stdOut io.Writer, stdErr io.Writer, exit func(code int)) {
 		doCompile(flag.Args()[1:], stdErr, exit)
 	case "run":
 		doRun(flag.Args()[1:], stdOut, stdErr, exit)
+	case "version":
+		fmt.Fprintln(stdOut, version.GetWazeroVersion())
+		exit(0)
 	default:
 		fmt.Fprintln(stdErr, "invalid command")
 		printUsage(stdErr)
@@ -260,6 +264,7 @@ func printUsage(stdErr io.Writer) {
 	fmt.Fprintln(stdErr, "Commands:")
 	fmt.Fprintln(stdErr, "  compile\tPre-compiles a WebAssembly binary")
 	fmt.Fprintln(stdErr, "  run\t\tRuns a WebAssembly binary")
+	fmt.Fprintln(stdErr, "  version\tDisplays the version of wazero CLI")
 }
 
 func printCompileUsage(stdErr io.Writer, flags *flag.FlagSet) {

cmd/wazero/wazero_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"github.com/tetratelabs/wazero/internal/testing/require"
+	"github.com/tetratelabs/wazero/internal/version"
 )
 
 //go:embed testdata/wasi_arg.wasm
@@ -281,6 +282,13 @@ func TestRun(t *testing.T) {
 	}
 }
 
+func TestVersion(t *testing.T) {
+	exitCode, stdOut, stdErr := runMain(t, []string{"version"})
+	require.Equal(t, 0, exitCode)
+	require.Equal(t, version.GetWazeroVersion()+"\n", stdOut)
+	require.Equal(t, "", stdErr)
+}
+
 func TestRun_Errors(t *testing.T) {
 	wasmPath := filepath.Join(t.TempDir(), "test.wasm")
 	require.NoError(t, os.WriteFile(wasmPath, wasmWasiArg, 0o700))
@@ -332,7 +340,17 @@ func TestRun_Errors(t *testing.T) {
 func TestHelp(t *testing.T) {
 	exitCode, _, stdErr := runMain(t, []string{"-h"})
 	require.Equal(t, 0, exitCode)
-	require.Contains(t, stdErr, "wazero CLI\n\nUsage:")
+	fmt.Println(stdErr)
+	require.Equal(t, `wazero CLI
+
+Usage:
+  wazero <command>
+
+Commands:
+  compile	Pre-compiles a WebAssembly binary
+  run		Runs a WebAssembly binary
+  version	Displays the version of wazero CLI
+`, stdErr)
 }
 
 func runMain(t *testing.T, args []string) (int, string, string) {

internal/version/version.go

@@ -25,6 +25,11 @@ func GetWazeroVersion() (ret string) {
 				ret = dep.Version
 			}
 		}
+
+		// In wazero CLI, wazero is a main module, so we have to get the version info from info.Main.
+		if ret == "dev" {
+			ret = info.Main.Version
+		}
 	}
 	return
 }