test(types/address): add additional unit tests for address.LengthPref…

…ix and a… (cosmos#19964)

types/address/store_key_test.go

@@ -18,6 +18,7 @@ func (suite *StoreKeySuite) TestLengthPrefix() {
 	require := suite.Require()
 	addr10byte := []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
 	addr20byte := []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19}
+	var addr0byte []byte
 	addr256byte := make([]byte, 256)
 
 	tests := []struct {
@@ -28,11 +29,11 @@ func (suite *StoreKeySuite) TestLengthPrefix() {
 	}{
 		{"10-byte address", addr10byte, append([]byte{byte(10)}, addr10byte...), false},
 		{"20-byte address", addr20byte, append([]byte{byte(20)}, addr20byte...), false},
+		{"0-byte address", addr0byte, addr0byte, false},
 		{"256-byte address (too long)", addr256byte, nil, true},
 	}
 
 	for _, tt := range tests {
-		tt := tt
 		suite.Run(tt.name, func() {
 			storeKey, err := address.LengthPrefix(tt.addr)
 			if tt.expErr {
@@ -44,3 +45,34 @@ func (suite *StoreKeySuite) TestLengthPrefix() {
 		})
 	}
 }
+
+func (suite *StoreKeySuite) TestMustLengthPrefix() {
+	require := suite.Require()
+	addr10byte := []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	addr256byte := make([]byte, 256)
+
+	tests := []struct {
+		name        string
+		addr        []byte
+		expStoreKey []byte
+		expPanic    bool
+	}{
+		{"10-byte address with length prefix", addr10byte, append([]byte{byte(10)}, addr10byte...), false},
+		{"256-byte address triggers panic due to excessive length", addr256byte, nil, true},
+	}
+
+	for _, tt := range tests {
+		suite.Run(tt.name, func() {
+			defer func() {
+				r := recover()
+				if tt.expPanic {
+					require.NotNil(r)
+				} else {
+					require.Nil(r)
+				}
+			}()
+			storeKey := address.MustLengthPrefix(tt.addr)
+			require.Equal(tt.expStoreKey, storeKey)
+		})
+	}
+}