feat(shwap): Add validation file

share/new_eds/accessor.go

@@ -32,3 +32,12 @@ type AccessorCloser interface {
 	Accessor
 	io.Closer
 }
+
+type accessorCloser struct {
+	Accessor
+	io.Closer
+}
+
+func WithCloser(a Accessor, c io.Closer) AccessorCloser {
+	return &accessorCloser{a, c}
+}

share/new_eds/validation.go

@@ -0,0 +1,76 @@
+package eds
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync/atomic"
+
+	"github.com/celestiaorg/rsmt2d"
+
+	"github.com/celestiaorg/celestia-node/share"
+	"github.com/celestiaorg/celestia-node/share/shwap"
+)
+
+var _ Accessor = validation{}
+
+// ErrOutOfBounds is returned whenever an index is out of bounds.
+var ErrOutOfBounds = errors.New("index is out of bounds")
+
+// validation is a  Accessor implementation that performs sanity checks on methods. It wraps
+// another  Accessor and performs bounds checks on index arguments.
+type validation struct {
+	Accessor
+	size *atomic.Int32
+}
+
+func WithValidation(f Accessor) Accessor {
+	return &validation{Accessor: f, size: new(atomic.Int32)}
+}
+
+func (f validation) Size(ctx context.Context) int {
+	size := f.size.Load()
+	if size == 0 {
+		loaded := f.Accessor.Size(ctx)
+		f.size.Store(int32(loaded))
+		return loaded
+	}
+	return int(size)
+}
+
+func (f validation) Sample(ctx context.Context, rowIdx, colIdx int) (shwap.Sample, error) {
+	if err := validateIndexBounds(ctx, f, colIdx); err != nil {
+		return shwap.Sample{}, fmt.Errorf("col: %w", err)
+	}
+	if err := validateIndexBounds(ctx, f, rowIdx); err != nil {
+		return shwap.Sample{}, fmt.Errorf("row: %w", err)
+	}
+	return f.Accessor.Sample(ctx, rowIdx, colIdx)
+}
+
+func (f validation) AxisHalf(ctx context.Context, axisType rsmt2d.Axis, axisIdx int) (AxisHalf, error) {
+	if err := validateIndexBounds(ctx, f, axisIdx); err != nil {
+		return AxisHalf{}, fmt.Errorf("%s: %w", axisType, err)
+	}
+	return f.Accessor.AxisHalf(ctx, axisType, axisIdx)
+}
+
+func (f validation) RowNamespaceData(
+	ctx context.Context,
+	namespace share.Namespace,
+	rowIdx int,
+) (shwap.RowNamespaceData, error) {
+	if err := validateIndexBounds(ctx, f, rowIdx); err != nil {
+		return shwap.RowNamespaceData{}, fmt.Errorf("row: %w", err)
+	}
+	return f.Accessor.RowNamespaceData(ctx, namespace, rowIdx)
+}
+
+// validateIndexBounds checks if the index is within the bounds of the eds.
+func validateIndexBounds(ctx context.Context, f Accessor, idx int) error {
+	size := f.Size(ctx)
+	if idx < 0 || idx >= size {
+		return fmt.Errorf("%w: index %d is out of bounds: [0, %d)", ErrOutOfBounds, idx, size)
+	}
+	return nil
+}

share/new_eds/validation_test.go

@@ -0,0 +1,103 @@
+package eds
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/celestiaorg/rsmt2d"
+
+	"github.com/celestiaorg/celestia-node/share/eds/edstest"
+	"github.com/celestiaorg/celestia-node/share/sharetest"
+	"github.com/celestiaorg/celestia-node/share/shwap"
+)
+
+func TestValidation_Sample(t *testing.T) {
+	tests := []struct {
+		name           string
+		rowIdx, colIdx int
+		odsSize        int
+		expectFail     bool
+	}{
+		{"ValidIndices", 3, 2, 4, false},
+		{"OutOfBoundsX", 8, 3, 4, true},
+		{"OutOfBoundsY", 3, 8, 4, true},
+		{"NegativeX", -1, 4, 8, true},
+		{"NegativeY", 3, -1, 8, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			randEDS := edstest.RandEDS(t, tt.odsSize)
+			accessor := &Rsmt2D{ExtendedDataSquare: randEDS}
+			validation := WithValidation(WithCloser(accessor, nil))
+
+			_, err := validation.Sample(context.Background(), tt.rowIdx, tt.colIdx)
+			if tt.expectFail {
+				require.ErrorIs(t, err, ErrOutOfBounds)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestValidation_AxisHalf(t *testing.T) {
+	tests := []struct {
+		name       string
+		axisType   rsmt2d.Axis
+		axisIdx    int
+		odsSize    int
+		expectFail bool
+	}{
+		{"ValidIndex", rsmt2d.Row, 2, 4, false},
+		{"OutOfBounds", rsmt2d.Col, 8, 4, true},
+		{"NegativeIndex", rsmt2d.Row, -1, 4, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			randEDS := edstest.RandEDS(t, tt.odsSize)
+			accessor := &Rsmt2D{ExtendedDataSquare: randEDS}
+			validation := WithValidation(WithCloser(accessor, nil))
+
+			_, err := validation.AxisHalf(context.Background(), tt.axisType, tt.axisIdx)
+			if tt.expectFail {
+				require.ErrorIs(t, err, ErrOutOfBounds)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestValidation_RowNamespaceData(t *testing.T) {
+	tests := []struct {
+		name       string
+		rowIdx     int
+		odsSize    int
+		expectFail bool
+	}{
+		{"ValidIndex", 3, 4, false},
+		{"OutOfBounds", 8, 4, true},
+		{"NegativeIndex", -1, 4, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			randEDS := edstest.RandEDS(t, tt.odsSize)
+			accessor := &Rsmt2D{ExtendedDataSquare: randEDS}
+			validation := WithValidation(WithCloser(accessor, nil))
+
+			ns := sharetest.RandV0Namespace()
+			_, err := validation.RowNamespaceData(context.Background(), ns, tt.rowIdx)
+			if tt.expectFail {
+				require.ErrorIs(t, err, ErrOutOfBounds)
+			} else {
+				require.True(t, err == nil || errors.Is(err, shwap.ErrNamespaceOutsideRange), err)
+			}
+		})
+	}
+}