fix: ensure usrlocalsharelima.Dir() works when called from tests (fixes lima-vm#3208)

Author: Konikz

Diff for: pkg/usrlocalsharelima/standalone_test.go

@@ -0,0 +1,67 @@
+// SPDX-FileCopyrightText: Copyright The Lima Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package usrlocalsharelima
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+// TestDirInTestEnvironment tests that usrlocalsharelima.Dir() works correctly
+// when called from tests, where os.Executable is located in a temp directory.
+// This test verifies that the guestagent binary can be found relative to the
+// test executable's location.
+func TestDirInTestEnvironment(t *testing.T) {
+	// Get the test executable path (will be in a temp directory)
+	testExe, err := os.Executable()
+	if err != nil {
+		t.Fatalf("Failed to get test executable path: %v", err)
+	}
+
+	// Determine architecture for binary name
+	arch := "aarch64"
+	if runtime.GOARCH == "amd64" {
+		arch = "x86_64"
+	}
+	
+	// Create guestagent binary in the first expected location
+	// (same directory as test executable)
+	gaBinary1 := filepath.Join(filepath.Dir(testExe), fmt.Sprintf("lima-guestagent.Linux-%s", arch))
+	err = os.WriteFile(gaBinary1, []byte("dummy"), 0755)
+	if err != nil {
+		t.Fatalf("Failed to create guestagent binary: %v", err)
+	}
+	defer os.Remove(gaBinary1)
+
+	// Create guestagent binary in the second expected location
+	// (share/lima directory relative to test executable)
+	shareDir := filepath.Join(filepath.Dir(filepath.Dir(testExe)), "share", "lima")
+	err = os.MkdirAll(shareDir, 0755)
+	if err != nil {
+		t.Fatalf("Failed to create share directory: %v", err)
+	}
+	defer os.RemoveAll(shareDir)
+
+	gaBinary2 := filepath.Join(shareDir, fmt.Sprintf("lima-guestagent.Linux-%s", arch))
+	err = os.WriteFile(gaBinary2, []byte("dummy"), 0755)
+	if err != nil {
+		t.Fatalf("Failed to create guestagent binary: %v", err)
+	}
+	defer os.Remove(gaBinary2)
+
+	// Test that Dir() can find the binary
+	dir, err := Dir()
+	if err != nil {
+		t.Fatalf("Dir() failed: %v", err)
+	}
+
+	// Verify that Dir() returns the correct directory
+	expectedDir := filepath.Dir(gaBinary1)
+	if dir != expectedDir {
+		t.Errorf("Expected directory %q, got %q", expectedDir, dir)
+	}
+}