feat(proxystate): add state file package for persistent proxy

internal/proxystate/state_test.go

@@ -0,0 +1,56 @@
+package proxystate_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/safedep/pmg/internal/proxystate"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWriteAndRead(t *testing.T) {
+	dir := t.TempDir()
+	path := proxystate.StatePath(dir)
+
+	s := proxystate.State{PID: 12345, Addr: "127.0.0.1:9999", CACertPath: "/tmp/ca.pem"}
+	require.NoError(t, proxystate.Write(path, s))
+
+	got, err := proxystate.Read(path)
+	require.NoError(t, err)
+	assert.Equal(t, s.PID, got.PID)
+	assert.Equal(t, s.Addr, got.Addr)
+	assert.Equal(t, s.CACertPath, got.CACertPath)
+}
+
+func TestReadMissingFile(t *testing.T) {
+	_, err := proxystate.Read(filepath.Join(t.TempDir(), "nonexistent.json"))
+	assert.Error(t, err)
+}
+
+func TestRemove(t *testing.T) {
+	dir := t.TempDir()
+	path := proxystate.StatePath(dir)
+
+	require.NoError(t, proxystate.Write(path, proxystate.State{PID: 1, Addr: "127.0.0.1:1"}))
+	require.NoError(t, proxystate.Remove(path))
+
+	_, err := os.Stat(path)
+	assert.True(t, os.IsNotExist(err))
+}
+
+func TestIsRunningCurrentProcess(t *testing.T) {
+	s := proxystate.State{PID: os.Getpid(), Addr: "127.0.0.1:1"}
+	assert.True(t, s.IsRunning())
+}
+
+func TestIsRunningDeadPID(t *testing.T) {
+	s := proxystate.State{PID: 999999999}
+	assert.False(t, s.IsRunning())
+}
+
+func TestStatePath(t *testing.T) {
+	path := proxystate.StatePath("/some/config/dir")
+	assert.Equal(t, "/some/config/dir/proxy-state.json", path)
+}