feat: 实现 test/harness 集成测试启动器

test/harness/binary.go

@@ -0,0 +1,63 @@
+package harness
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"sync"
+)
+
+var (
+	binOnce sync.Once
+	binPath string
+	binErr  error
+)
+
+// Binary 返回已编译好的 nixmsg 可执行文件路径（整个进程只编译一次）。
+func Binary() (string, error) {
+	binOnce.Do(func() {
+		root, err := moduleRoot()
+		if err != nil {
+			binErr = err
+			return
+		}
+		dir, err := os.MkdirTemp("", "nixmsg-harness-bin-*")
+		if err != nil {
+			binErr = err
+			return
+		}
+		name := "nixmsg"
+		if runtime.GOOS == "windows" {
+			name += ".exe"
+		}
+		out := filepath.Join(dir, name)
+		cmd := exec.Command("go", "build", "-o", out, "./cmd/nixmsg")
+		cmd.Dir = root
+		cmd.Env = append(os.Environ(), "CGO_ENABLED=0")
+		if outBytes, runErr := cmd.CombinedOutput(); runErr != nil {
+			binErr = fmt.Errorf("build nixmsg: %w\n%s", runErr, outBytes)
+			return
+		}
+		binPath = out
+	})
+	return binPath, binErr
+}
+
+func moduleRoot() (string, error) {
+	dir, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+	for {
+		if _, statErr := os.Stat(filepath.Join(dir, "go.mod")); statErr == nil {
+			return dir, nil
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			return "", fmt.Errorf("go.mod not found from %s", dir)
+		}
+		dir = parent
+	}
+}