feat: add stable cursors and effective config rendering

internal/domain/cursor_test.go

@@ -0,0 +1,74 @@
+package domain
+
+import (
+	"bytes"
+	"errors"
+	"strings"
+	"testing"
+)
+
+func TestAuthenticatedCursorRoundTrip_HP_CTL_06(t *testing.T) {
+	t.Parallel()
+
+	codec, err := NewCursorCodec(bytes.Repeat([]byte{0x42}, 32))
+	if err != nil {
+		t.Fatal(err)
+	}
+	filters := HashCursorFilters([]byte("client=host-1\x00streams=stdout"))
+	want := Cursor{Kind: CursorKindOutput, FilterHash: filters, Position: []byte("uuid/event/offset"), SnapshotBoundary: []byte("upper-event")}
+	token, err := codec.Encode(want)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := codec.Decode(token, CursorKindOutput, filters)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.Kind != want.Kind || got.FilterHash != want.FilterHash || !bytes.Equal(got.Position, want.Position) || !bytes.Equal(got.SnapshotBoundary, want.SnapshotBoundary) {
+		t.Fatalf("decoded cursor = %+v, want %+v", got, want)
+	}
+}
+
+func TestCursorForgeryAndFilterBinding_BH_CTL_01(t *testing.T) {
+	t.Parallel()
+
+	codec, _ := NewCursorCodec(bytes.Repeat([]byte{0x42}, 32))
+	filters := HashCursorFilters([]byte("client=one"))
+	token, _ := codec.Encode(Cursor{Kind: CursorKindCommands, FilterHash: filters, Position: []byte("position"), SnapshotBoundary: []byte("boundary")})
+	forged := []byte(token)
+	forged[len(forged)/2] ^= 1
+	if _, err := codec.Decode(string(forged), CursorKindCommands, filters); !errors.Is(err, ErrInvalidCursor) {
+		t.Fatalf("forged cursor error = %v", err)
+	}
+	otherFilters := HashCursorFilters([]byte("client=two"))
+	if _, err := codec.Decode(token, CursorKindCommands, otherFilters); !errors.Is(err, ErrCursorFilterMismatch) {
+		t.Fatalf("filter mismatch error = %v", err)
+	}
+	if _, err := codec.Decode(token, CursorKindOutput, filters); !errors.Is(err, ErrInvalidCursor) {
+		t.Fatalf("kind mismatch error = %v", err)
+	}
+	for _, malformed := range []string{"", "***", strings.Repeat("a", 4096)} {
+		if _, err := codec.Decode(malformed, CursorKindCommands, filters); !errors.Is(err, ErrInvalidCursor) {
+			t.Errorf("malformed cursor %q error = %v", malformed[:min(len(malformed), 16)], err)
+		}
+	}
+}
+
+func TestCursorInputBounds_BH_CTL_01(t *testing.T) {
+	t.Parallel()
+
+	if _, err := NewCursorCodec([]byte("short")); !errors.Is(err, ErrInvalidCursor) {
+		t.Fatalf("short key error = %v", err)
+	}
+	codec, _ := NewCursorCodec(bytes.Repeat([]byte{1}, 32))
+	filter := HashCursorFilters(nil)
+	for _, cursor := range []Cursor{
+		{Kind: 0, FilterHash: filter, Position: []byte("x"), SnapshotBoundary: []byte("y")},
+		{Kind: CursorKindCommands, FilterHash: filter, SnapshotBoundary: []byte("y")},
+		{Kind: CursorKindCommands, FilterHash: filter, Position: bytes.Repeat([]byte("x"), maxCursorFieldBytes+1), SnapshotBoundary: []byte("y")},
+	} {
+		if _, err := codec.Encode(cursor); !errors.Is(err, ErrInvalidCursor) {
+			t.Errorf("invalid cursor error = %v", err)
+		}
+	}
+}