chore: import upstream snapshot with attribution

internal/server/serverid_test.go

@@ -0,0 +1,50 @@
+package server
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadOrCreateServerID_GeneratesWhenMissing(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "nested", "server.id")
+
+	id, err := LoadOrCreateServerID(path)
+	require.NoError(t, err)
+	_, parseErr := uuid.Parse(id)
+	assert.NoError(t, parseErr)
+
+	// Persisted to disk.
+	data, err := os.ReadFile(path)
+	require.NoError(t, err)
+	assert.Contains(t, string(data), id)
+}
+
+func TestLoadOrCreateServerID_ReusesExisting(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "server.id")
+
+	first, err := LoadOrCreateServerID(path)
+	require.NoError(t, err)
+
+	second, err := LoadOrCreateServerID(path)
+	require.NoError(t, err)
+
+	assert.Equal(t, first, second, "server id should be stable across calls")
+}
+
+func TestLoadOrCreateServerID_ReplacesMalformedFile(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "server.id")
+	require.NoError(t, os.WriteFile(path, []byte("not a uuid"), 0o600))
+
+	id, err := LoadOrCreateServerID(path)
+	require.NoError(t, err)
+	_, parseErr := uuid.Parse(id)
+	assert.NoError(t, parseErr)
+}