add comments

x/authz/keeper/keys.go

@@ -106,23 +106,26 @@ func firstAddressFromGrantStoreKey(key []byte) sdk.AccAddress {
 	return sdk.AccAddress(key[1 : 1+addrLen])
 }
 
+// grantKeyToString converts a byte slice representing a grant key into a human-readable UTF-8 encoded string.
+// The expected format of the byte slice is as follows:
+// 0x01<prefix(1 Byte)><granterAddressLen(1 Byte)><granterAddress_Bytes><granteeAddressLen(1 Byte)><granteeAddress_Bytes><msgType_Bytes>
 func grantKeyToString(skey []byte) string {
 	// get grant key prefix
 	prefix := skey[bytePositionOfGrantKeyPrefix]
 
-	// get granter address len and granter address
+	// get granter address len and granter address, found at a specified position in the byte slice
 	granterAddressLen := int(skey[bytePositionOfGranterAddressLen])
 	startByteIndex := omitTwoBytes
 	endByteIndex := startByteIndex + granterAddressLen
 	granterAddressBytes := skey[startByteIndex:endByteIndex]
 
-	// get grantee address len and grantee address
+	// get grantee address len and grantee address, found at a specified position in the byte slice
 	granteeAddressLen := int(skey[endByteIndex])
 	startByteIndex = endByteIndex + 1
 	endByteIndex = startByteIndex + granteeAddressLen
 	granteeAddressBytes := skey[startByteIndex:endByteIndex]
 
-	// get message type
+	// get message type, start from the specific byte to the end
 	startByteIndex = endByteIndex
 	msgTypeBytes := skey[startByteIndex:]
 

x/authz/keeper/keys_test.go

@@ -3,6 +3,7 @@ package keeper
 import (
 	"testing"
 	"time"
+	"unicode/utf8"
 
 	"github.com/stretchr/testify/require"
 
@@ -47,11 +48,13 @@ func TestParseGrantStoreKey(t *testing.T) {
 	granterAddr, _ := sdk.AccAddressFromBech32("cosmos15ky9du8a2wlstz6fpx3p4mqpjyrm5cgqjwl8sq")
 	msg := "/cosmos.bank.v1beta1.MsgSend"
 	skey := grantStoreKey(granteeAddr, granterAddr, msg)
+	require.False(t, utf8.Valid(skey))
 
 	// Action
 	actual := grantKeyToString(skey)
 
 	// Assert
 	expected := "1|20|cosmos15ky9du8a2wlstz6fpx3p4mqpjyrm5cgqjwl8sq|20|cosmos15ky9du8a2wlstz6fpx3p4mqpjyrm5cgp0ctjdj|/cosmos.bank.v1beta1.MsgSend"
 	require.Equal(t, expected, actual)
+	require.True(t, utf8.ValidString(actual))
 }