Review error wrappings

internal/trie/node/decode.go

@@ -13,9 +13,17 @@ import (
 )
 
 var (
+	// ErrDecodeValue is defined since no sentinel error is defined
+	// in the scale package.
+	// TODO remove once the following issue is done:
+	// https://github.com/ChainSafe/gossamer/issues/2631 .
 	ErrDecodeValue        = errors.New("cannot decode value")
 	ErrReadChildrenBitmap = errors.New("cannot read children bitmap")
-	ErrDecodeChildHash    = errors.New("cannot decode child hash")
+	// ErrDecodeChildHash is defined since no sentinel error is defined
+	// in the scale package.
+	// TODO remove once the following issue is done:
+	// https://github.com/ChainSafe/gossamer/issues/2631 .
+	ErrDecodeChildHash = errors.New("cannot decode child hash")
 )
 
 // Decode decodes a node from a reader.
@@ -27,7 +35,7 @@ var (
 func Decode(reader io.Reader) (n *Node, err error) {
 	variant, partialKeyLength, err := decodeHeader(reader)
 	if err != nil {
-		return nil, fmt.Errorf("cannot decode header: %w", err)
+		return nil, fmt.Errorf("decoding header: %w", err)
 	}
 
 	switch variant {

internal/trie/node/decode_test.go

@@ -43,12 +43,12 @@ func Test_Decode(t *testing.T) {
 		"no data": {
 			reader:     bytes.NewReader(nil),
 			errWrapped: io.EOF,
-			errMessage: "cannot decode header: cannot read header byte: EOF",
+			errMessage: "decoding header: reading header byte: EOF",
 		},
 		"unknown node variant": {
 			reader:     bytes.NewReader([]byte{0}),
 			errWrapped: ErrVariantUnknown,
-			errMessage: "cannot decode header: cannot decode header byte: node variant is unknown: for header byte 00000000",
+			errMessage: "decoding header: decoding header byte: node variant is unknown: for header byte 00000000",
 		},
 		"leaf decoding error": {
 			reader: bytes.NewReader([]byte{
@@ -57,7 +57,7 @@ func Test_Decode(t *testing.T) {
 			}),
 			errWrapped: io.EOF,
 			errMessage: "cannot decode leaf: cannot decode key: " +
-				"cannot read from reader: EOF",
+				"reading from reader: EOF",
 		},
 		"leaf success": {
 			reader: bytes.NewReader(
@@ -82,7 +82,7 @@ func Test_Decode(t *testing.T) {
 			}),
 			errWrapped: io.EOF,
 			errMessage: "cannot decode branch: cannot decode key: " +
-				"cannot read from reader: EOF",
+				"reading from reader: EOF",
 		},
 		"branch success": {
 			reader: bytes.NewReader(
@@ -194,7 +194,7 @@ func Test_decodeBranch(t *testing.T) {
 			variant:          branchVariant.bits,
 			partialKeyLength: 1,
 			errWrapped:       io.EOF,
-			errMessage:       "cannot decode key: cannot read from reader: EOF",
+			errMessage:       "cannot decode key: reading from reader: EOF",
 		},
 		"children bitmap read error": {
 			reader: bytes.NewBuffer([]byte{
@@ -317,7 +317,7 @@ func Test_decodeLeaf(t *testing.T) {
 			variant:          leafVariant.bits,
 			partialKeyLength: 1,
 			errWrapped:       io.EOF,
-			errMessage:       "cannot decode key: cannot read from reader: EOF",
+			errMessage:       "cannot decode key: reading from reader: EOF",
 		},
 		"value decoding error": {
 			reader: bytes.NewBuffer([]byte{

internal/trie/node/header.go

@@ -75,13 +75,13 @@ func decodeHeader(reader io.Reader) (variant byte,
 	buffer := make([]byte, 1)
 	_, err = reader.Read(buffer)
 	if err != nil {
-		return 0, 0, fmt.Errorf("cannot read header byte: %w", err)
+		return 0, 0, fmt.Errorf("reading header byte: %w", err)
 	}
 
 	variant, partialKeyLengthHeader, partialKeyLengthHeaderMask,
 		err := decodeHeaderByte(buffer[0])
 	if err != nil {
-		return 0, 0, fmt.Errorf("cannot decode header byte: %w", err)
+		return 0, 0, fmt.Errorf("decoding header byte: %w", err)
 	}
 
 	partialKeyLength = uint16(partialKeyLengthHeader)
@@ -100,7 +100,7 @@ func decodeHeader(reader io.Reader) (variant byte,
 	for {
 		_, err = reader.Read(buffer)
 		if err != nil {
-			return 0, 0, fmt.Errorf("cannot read key length: %w", err)
+			return 0, 0, fmt.Errorf("reading key length: %w", err)
 		}
 
 		previousKeyLength = partialKeyLength

internal/trie/node/header_test.go

@@ -286,14 +286,14 @@ func Test_decodeHeader(t *testing.T) {
 				{buffArgCap: 1, err: errTest},
 			},
 			errWrapped: errTest,
-			errMessage: "cannot read header byte: test error",
+			errMessage: "reading header byte: test error",
 		},
 		"header byte decoding error": {
 			reads: []readCall{
 				{buffArgCap: 1, read: []byte{0b0011_1110}},
 			},
 			errWrapped: ErrVariantUnknown,
-			errMessage: "cannot decode header byte: node variant is unknown: for header byte 00111110",
+			errMessage: "decoding header byte: node variant is unknown: for header byte 00111110",
 		},
 		"partial key length contained in first byte": {
 			reads: []readCall{
@@ -308,7 +308,7 @@ func Test_decodeHeader(t *testing.T) {
 				{buffArgCap: 1, err: errTest},
 			},
 			errWrapped: errTest,
-			errMessage: "cannot read key length: test error",
+			errMessage: "reading key length: test error",
 		},
 		"partial key length spread on multiple bytes": {
 			reads: []readCall{

internal/trie/node/key.go

@@ -24,7 +24,7 @@ func decodeKey(reader io.Reader, partialKeyLength uint16) (b []byte, err error)
 	key := make([]byte, partialKeyLength/2+partialKeyLength%2)
 	n, err := reader.Read(key)
 	if err != nil {
-		return nil, fmt.Errorf("cannot read from reader: %w", err)
+		return nil, fmt.Errorf("reading from reader: %w", err)
 	} else if n != len(key) {
 		return nil, fmt.Errorf("%w: read %d bytes instead of expected %d bytes",
 			ErrReaderMismatchCount, n, len(key))

internal/trie/node/key_test.go

@@ -87,7 +87,7 @@ func Test_decodeKey(t *testing.T) {
 			},
 			partialKeyLength: 5,
 			errWrapped:       errTest,
-			errMessage:       "cannot read from reader: test error",
+			errMessage:       "reading from reader: test error",
 		},
 
 		"key read bytes count mismatch": {