internal/format/packidx/bloom: Add

1 files changed, 128 insertions, 0 deletions

diff --git a/internal/format/packidx/bloom/bloom_test.go b/internal/format/packidx/bloom/bloom_test.go
new file mode 100644
index 00000000..16295afd
--- /dev/null
+++ b/internal/format/packidx/bloom/bloom_test.go
@@ -0,0 +1,128 @@
+package bloom_test
+
+import (
+	"encoding/binary"
+	"errors"
+	"testing"
+
+	"lindenii.org/go/furgit/internal/format/packidx/bloom"
+	"lindenii.org/go/furgit/object/id"
+)
+
+func validFilter(t *testing.T, format id.ObjectFormat) []byte {
+	// TODO: maybe testgit should have something like this?
+	t.Helper()
+
+	builder, err := bloom.NewBuilder(format, 4, 2)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return builder.Bytes()
+}
+
+func otherFormat(t *testing.T, format id.ObjectFormat) id.ObjectFormat {
+	t.Helper()
+
+	for _, candidate := range id.SupportedObjectFormats() {
+		if candidate != format {
+			return candidate
+		}
+	}
+
+	t.Skip("only one supported object format")
+
+	return id.ObjectFormatUnknown
+}
+
+func TestParseValid(t *testing.T) {
+	t.Parallel()
+
+	for _, format := range id.SupportedObjectFormats() {
+		t.Run(format.String(), func(t *testing.T) {
+			t.Parallel()
+
+			_, err := bloom.Parse(validFilter(t, format), format)
+			if err != nil {
+				t.Fatalf("Parse rejected a valid filter: %v", err)
+			}
+		})
+	}
+}
+
+func TestParseMalformed(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name   string
+		mangle func(data []byte) []byte
+	}{
+		{"truncated", func(data []byte) []byte { return data[:bloom.HeaderLen-1] }},
+		{"bad signature", func(data []byte) []byte {
+			data[0] ^= 0xff
+
+			return data
+		}},
+		{"bad version", func(data []byte) []byte {
+			binary.BigEndian.PutUint32(data[4:], 99)
+
+			return data
+		}},
+		{"non power of two", func(data []byte) []byte {
+			binary.BigEndian.PutUint32(data[12:], 3)
+
+			return data
+		}},
+		{"zero probe count", func(data []byte) []byte {
+			binary.BigEndian.PutUint16(data[16:], 0)
+
+			return data
+		}},
+		{"parameters exceed hash", func(data []byte) []byte {
+			binary.BigEndian.PutUint32(data[12:], 1<<31)
+			binary.BigEndian.PutUint16(data[16:], 30)
+
+			return data
+		}},
+		{"nonzero padding", func(data []byte) []byte {
+			data[20] = 1
+
+			return data
+		}},
+		{"size disagrees", func(data []byte) []byte { return data[:len(data)-1] }},
+	}
+
+	for _, format := range id.SupportedObjectFormats() {
+		t.Run(format.String(), func(t *testing.T) {
+			t.Parallel()
+
+			for _, tc := range cases {
+				t.Run(tc.name, func(t *testing.T) {
+					t.Parallel()
+
+					data := tc.mangle(append([]byte(nil), validFilter(t, format)...))
+
+					_, err := bloom.Parse(data, format)
+					if !errors.Is(err, bloom.ErrMalformedBloomFilter) {
+						t.Fatalf("Parse error = %v, want ErrMalformedBloomFilter", err)
+					}
+				})
+			}
+		})
+	}
+}
+
+func TestParseHashMismatch(t *testing.T) {
+	t.Parallel()
+
+	for _, format := range id.SupportedObjectFormats() {
+		t.Run(format.String(), func(t *testing.T) {
+			t.Parallel()
+
+			_, err := bloom.Parse(validFilter(t, format), otherFormat(t, format))
+			if !errors.Is(err, bloom.ErrMalformedBloomFilter) {
+				t.Fatalf("Parse error = %v, want ErrMalformedBloomFilter", err)
+			}
+		})
+	}
+}