fix(cli): fall back to module version when ldflags is absent

cmd/she/main.go

@@ -6,14 +6,31 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"runtime/debug"
 	"strings"
 
 	"github.com/antonysastre/sheets/internal/sheet"
 )
 
 // version is overridden at build time via -ldflags "-X main.version=...".
+// When unset (e.g. `go install ...@latest`, which bypasses our Makefile),
+// versionString falls back to the module version from runtime/debug.
 var version = "dev"
 
+func versionString() string {
+	if version != "dev" {
+		return version
+	}
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return version
+	}
+	if v := info.Main.Version; v != "" && v != "(devel)" {
+		return v
+	}
+	return version
+}
+
 func main() {
 	os.Exit(run(os.Args, os.Stdout, os.Stderr))
 }
@@ -69,7 +86,7 @@ func run(args []string, stdout, stderr io.Writer) int {
 		printUsage(stdout)
 
 	case "--version", "-V":
-		_, _ = fmt.Fprintf(stdout, "she %s\n", version)
+		_, _ = fmt.Fprintf(stdout, "she %s\n", versionString())
 
 	// "--" ends option parsing, so the next argument is taken literally —
 	// the only way to view a sheet whose name begins with a dash.

cmd/she/main_test.go

@@ -65,3 +65,26 @@ func checkStream(t *testing.T, name, got, want string) {
 		t.Errorf("%s = %q, want it to contain %q", name, got, want)
 	}
 }
+
+// versionString prefers the ldflags-injected value when present so `make
+// build` carries `git describe`, but falls back to runtime/debug so a plain
+// `go install ...@latest` (no ldflags) still reports the module version.
+func TestVersionString(t *testing.T) {
+	orig := version
+	t.Cleanup(func() { version = orig })
+
+	version = "v1.2.3"
+	if got := versionString(); got != "v1.2.3" {
+		t.Errorf("ldflags-set: versionString() = %q, want %q", got, "v1.2.3")
+	}
+
+	// "dev" sentinel — fall back to runtime/debug. Under `go test`,
+	// debug.ReadBuildInfo populates a synthetic Main.Version of "(devel)",
+	// which versionString rejects in favor of "dev". We can't easily
+	// exercise the happy fallback path (it needs a module-aware install),
+	// so verify the (devel)-or-empty path stays at "dev".
+	version = "dev"
+	if got := versionString(); got != "dev" {
+		t.Errorf("dev sentinel: versionString() = %q, want %q", got, "dev")
+	}
+}