Port code to read cloned env

tools/cmd/ssh/main_test.go

@@ -0,0 +1,39 @@
+// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package ssh
+
+import (
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"kitty/tools/utils/shm"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+var _ = fmt.Print
+
+func TestCloneEnv(t *testing.T) {
+	env := map[string]string{"a": "1", "b": "2"}
+	data, err := json.Marshal(env)
+	if err != nil {
+		t.Fatal(err)
+	}
+	mmap, err := shm.CreateTemp("", 128)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer mmap.Unlink()
+	copy(mmap.Slice()[4:], data)
+	binary.BigEndian.PutUint32(mmap.Slice(), uint32(len(data)))
+	mmap.Close()
+	x, err := add_cloned_env(mmap.Name())
+	if err != nil {
+		t.Fatal(err)
+	}
+	diff := cmp.Diff(env, x)
+	if diff != "" {
+		t.Fatalf("Failed to deserialize env\n%s", diff)
+	}
+}