diff --git a/types/account_test.go b/types/account_test.go
new file mode 100644
index 000000000..aa222ee7e
--- /dev/null
+++ b/types/account_test.go
@@ -0,0 +1,132 @@
+package types_test
+
+import (
+	"encoding/hex"
+	"math/rand"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/tendermint/tendermint/crypto/ed25519"
+
+	"github.com/cosmos/cosmos-sdk/types"
+)
+
+var invalidstrs = []string{
+	"",
+	"hello, world!",
+	"0xAA",
+	"AAA",
+	types.Bech32PrefixAccAddr + "AB0C",
+	types.Bech32PrefixAccPub + "1234",
+	types.Bech32PrefixValAddr + "5678",
+	types.Bech32PrefixValPub + "BBAB",
+}
+
+func testMarshal(t *testing.T, original interface{}, res interface{}, marshal func() ([]byte, error), unmarshal func([]byte) error) {
+	bz, err := marshal()
+	require.Nil(t, err)
+	err = unmarshal(bz)
+	require.Nil(t, err)
+	require.Equal(t, original, res)
+}
+
+func TestRandBech32PubkeyConsistency(t *testing.T) {
+	var pub ed25519.PubKeyEd25519
+
+	for i := 0; i < 1000; i++ {
+		rand.Read(pub[:])
+
+		mustbech32accpub := types.MustBech32ifyAccPub(pub)
+		bech32accpub, err := types.Bech32ifyAccPub(pub)
+		require.Nil(t, err)
+		require.Equal(t, bech32accpub, mustbech32accpub)
+
+		mustbech32valpub := types.MustBech32ifyValPub(pub)
+		bech32valpub, err := types.Bech32ifyValPub(pub)
+		require.Nil(t, err)
+		require.Equal(t, bech32valpub, mustbech32valpub)
+
+		mustaccpub := types.MustGetAccPubKeyBech32(bech32accpub)
+		accpub, err := types.GetAccPubKeyBech32(bech32accpub)
+		require.Nil(t, err)
+		require.Equal(t, accpub, mustaccpub)
+
+		mustvalpub := types.MustGetValPubKeyBech32(bech32valpub)
+		valpub, err := types.GetValPubKeyBech32(bech32valpub)
+		require.Nil(t, err)
+		require.Equal(t, valpub, mustvalpub)
+
+		require.Equal(t, valpub, accpub)
+	}
+}
+
+func TestRandBech32AccAddrConsistency(t *testing.T) {
+	var pub ed25519.PubKeyEd25519
+
+	for i := 0; i < 1000; i++ {
+		rand.Read(pub[:])
+
+		acc := types.AccAddress(pub.Address())
+		res := types.AccAddress{}
+
+		testMarshal(t, &acc, &res, acc.MarshalJSON, (&res).UnmarshalJSON)
+		testMarshal(t, &acc, &res, acc.Marshal, (&res).Unmarshal)
+
+		str := acc.String()
+		res, err := types.AccAddressFromBech32(str)
+		require.Nil(t, err)
+		require.Equal(t, acc, res)
+
+		str = hex.EncodeToString(acc)
+		res, err = types.AccAddressFromHex(str)
+		require.Nil(t, err)
+		require.Equal(t, acc, res)
+	}
+
+	for _, str := range invalidstrs {
+		_, err := types.AccAddressFromHex(str)
+		require.NotNil(t, err)
+
+		_, err = types.AccAddressFromBech32(str)
+		require.NotNil(t, err)
+
+		err = (*types.AccAddress)(nil).UnmarshalJSON([]byte("\"" + str + "\""))
+		require.NotNil(t, err)
+	}
+}
+
+func TestValAddr(t *testing.T) {
+	var pub ed25519.PubKeyEd25519
+
+	for i := 0; i < 20; i++ {
+		rand.Read(pub[:])
+
+		acc := types.ValAddress(pub.Address())
+		res := types.ValAddress{}
+
+		testMarshal(t, &acc, &res, acc.MarshalJSON, (&res).UnmarshalJSON)
+		testMarshal(t, &acc, &res, acc.Marshal, (&res).Unmarshal)
+
+		str := acc.String()
+		res, err := types.ValAddressFromBech32(str)
+		require.Nil(t, err)
+		require.Equal(t, acc, res)
+
+		str = hex.EncodeToString(acc)
+		res, err = types.ValAddressFromHex(str)
+		require.Nil(t, err)
+		require.Equal(t, acc, res)
+	}
+
+	for _, str := range invalidstrs {
+		_, err := types.ValAddressFromHex(str)
+		require.NotNil(t, err)
+
+		_, err = types.ValAddressFromBech32(str)
+		require.NotNil(t, err)
+
+		err = (*types.ValAddress)(nil).UnmarshalJSON([]byte("\"" + str + "\""))
+		require.NotNil(t, err)
+	}
+}
diff --git a/types/coin_test.go b/types/coin_test.go
index 246339e97..0d47630f4 100644
--- a/types/coin_test.go
+++ b/types/coin_test.go
@@ -147,6 +147,46 @@ func TestMinusCoin(t *testing.T) {
 
 }
 
+func TestIsZeroCoins(t *testing.T) {
+	cases := []struct {
+		inputOne Coins
+		expected bool
+	}{
+		{Coins{}, true},
+		{Coins{NewCoin("A", 0)}, true},
+		{Coins{NewCoin("A", 0), NewCoin("B", 0)}, true},
+		{Coins{NewCoin("A", 1)}, false},
+		{Coins{NewCoin("A", 0), NewCoin("B", 1)}, false},
+	}
+
+	for _, tc := range cases {
+		res := tc.inputOne.IsZero()
+		require.Equal(t, tc.expected, res)
+	}
+}
+
+func TestEqualCoins(t *testing.T) {
+	cases := []struct {
+		inputOne Coins
+		inputTwo Coins
+		expected bool
+	}{
+		{Coins{}, Coins{}, true},
+		{Coins{NewCoin("A", 0)}, Coins{NewCoin("A", 0)}, true},
+		{Coins{NewCoin("A", 0), NewCoin("B", 1)}, Coins{NewCoin("A", 0), NewCoin("B", 1)}, true},
+		{Coins{NewCoin("A", 0)}, Coins{NewCoin("B", 0)}, false},
+		{Coins{NewCoin("A", 0)}, Coins{NewCoin("A", 1)}, false},
+		{Coins{NewCoin("A", 0)}, Coins{NewCoin("A", 0), NewCoin("B", 1)}, false},
+		// TODO: is it expected behaviour? shouldn't we sort the coins before comparing them?
+		{Coins{NewCoin("A", 0), NewCoin("B", 1)}, Coins{NewCoin("B", 1), NewCoin("A", 0)}, false},
+	}
+
+	for tcnum, tc := range cases {
+		res := tc.inputOne.IsEqual(tc.inputTwo)
+		require.Equal(t, tc.expected, res, "Equality is differed from expected. tc #%d, expected %b, actual %b.", tcnum, tc.expected, res)
+	}
+}
+
 func TestCoins(t *testing.T) {
 
 	//Define the coins to be used in tests
@@ -160,6 +200,7 @@ func TestCoins(t *testing.T) {
 	empty := Coins{
 		{"GOLD", NewInt(0)},
 	}
+	null := Coins{}
 	badSort1 := Coins{
 		{"TREE", NewInt(1)},
 		{"GAS", NewInt(1)},
@@ -184,6 +225,7 @@ func TestCoins(t *testing.T) {
 
 	assert.True(t, good.IsValid(), "Coins are valid")
 	assert.True(t, good.IsPositive(), "Expected coins to be positive: %v", good)
+	assert.False(t, null.IsPositive(), "Expected coins to not be positive: %v", null)
 	assert.True(t, good.IsGTE(empty), "Expected %v to be >= %v", good, empty)
 	assert.False(t, neg.IsPositive(), "Expected neg coins to not be positive: %v", neg)
 	assert.Zero(t, len(sum), "Expected 0 coins")
diff --git a/types/context_test.go b/types/context_test.go
index fb2786cff..900192285 100644
--- a/types/context_test.go
+++ b/types/context_test.go
@@ -98,3 +98,84 @@ func TestLogContext(t *testing.T) {
 	ctx.Logger().Error("error")
 	require.Equal(t, *logger.logs, []string{"debug", "info", "error"})
 }
+
+type dummy int64
+
+func (d dummy) Clone() interface{} {
+	return d
+}
+
+// Testing saving/loading primitive values to/from the context
+func TestContextWithPrimitive(t *testing.T) {
+	ctx := types.NewContext(nil, abci.Header{}, false, log.NewNopLogger())
+
+	clonerkey := "cloner"
+	stringkey := "string"
+	int32key := "int32"
+	uint32key := "uint32"
+	uint64key := "uint64"
+
+	keys := []string{clonerkey, stringkey, int32key, uint32key, uint64key}
+
+	for _, key := range keys {
+		require.Nil(t, ctx.Value(key))
+	}
+
+	clonerval := dummy(1)
+	stringval := "string"
+	int32val := int32(1)
+	uint32val := uint32(2)
+	uint64val := uint64(3)
+
+	ctx = ctx.
+		WithCloner(clonerkey, clonerval).
+		WithString(stringkey, stringval).
+		WithInt32(int32key, int32val).
+		WithUint32(uint32key, uint32val).
+		WithUint64(uint64key, uint64val)
+
+	require.Equal(t, clonerval, ctx.Value(clonerkey))
+	require.Equal(t, stringval, ctx.Value(stringkey))
+	require.Equal(t, int32val, ctx.Value(int32key))
+	require.Equal(t, uint32val, ctx.Value(uint32key))
+	require.Equal(t, uint64val, ctx.Value(uint64key))
+}
+
+// Testing saving/loading sdk type values to/from the context
+func TestContextWithCustom(t *testing.T) {
+	var ctx types.Context
+	require.True(t, ctx.IsZero())
+
+	require.Panics(t, func() { ctx.BlockHeader() })
+	require.Panics(t, func() { ctx.BlockHeight() })
+	require.Panics(t, func() { ctx.ChainID() })
+	require.Panics(t, func() { ctx.TxBytes() })
+	require.Panics(t, func() { ctx.Logger() })
+	require.Panics(t, func() { ctx.SigningValidators() })
+	require.Panics(t, func() { ctx.GasMeter() })
+
+	header := abci.Header{}
+	height := int64(1)
+	chainid := "chainid"
+	ischeck := true
+	txbytes := []byte("txbytes")
+	logger := NewMockLogger()
+	signvals := []abci.SigningValidator{abci.SigningValidator{}}
+	meter := types.NewGasMeter(10000)
+
+	ctx = types.NewContext(nil, header, ischeck, logger).
+		WithBlockHeight(height).
+		WithChainID(chainid).
+		WithTxBytes(txbytes).
+		WithSigningValidators(signvals).
+		WithGasMeter(meter)
+
+	require.Equal(t, header, ctx.BlockHeader())
+	require.Equal(t, height, ctx.BlockHeight())
+	require.Equal(t, chainid, ctx.ChainID())
+	require.Equal(t, txbytes, ctx.TxBytes())
+	require.Equal(t, logger, ctx.Logger())
+	require.Equal(t, signvals, ctx.SigningValidators())
+	require.Equal(t, meter, ctx.GasMeter())
+
+}
diff --git a/types/errors.go b/types/errors.go
index a106ee9bb..58541dfea 100644
--- a/types/errors.go
+++ b/types/errors.go
@@ -65,6 +65,10 @@ const (
 	MaximumCodespace CodespaceType = 65535
 )
 
+func unknownCodeMsg(code CodeType) string {
+	return fmt.Sprintf("unknown code %d", code)
+}
+
 // NOTE: Don't stringer this, we'll put better messages in later.
 // nolint: gocyclo
 func CodeToDefaultMsg(code CodeType) string {
@@ -96,7 +100,7 @@ func CodeToDefaultMsg(code CodeType) string {
 	case CodeMemoTooLarge:
 		return "memo too large"
 	default:
-		return fmt.Sprintf("unknown code %d", code)
+		return unknownCodeMsg(code)
 	}
 }
 
diff --git a/types/errors_test.go b/types/errors_test.go
index 959f059d0..e7625e96f 100644
--- a/types/errors_test.go
+++ b/types/errors_test.go
@@ -1,7 +1,6 @@
 package types
 
 import (
-	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -14,8 +13,13 @@ var codeTypes = []CodeType{
 	CodeUnauthorized,
 	CodeInsufficientFunds,
 	CodeUnknownRequest,
-	CodeUnknownAddress,
+	CodeInvalidAddress,
 	CodeInvalidPubKey,
+	CodeUnknownAddress,
+	CodeInsufficientCoins,
+	CodeInvalidCoins,
+	CodeOutOfGas,
+	CodeMemoTooLarge,
 }
 
 type errFn func(msg string) Error
@@ -27,24 +31,34 @@ var errFns = []errFn{
 	ErrUnauthorized,
 	ErrInsufficientFunds,
 	ErrUnknownRequest,
-	ErrUnknownAddress,
+	ErrInvalidAddress,
 	ErrInvalidPubKey,
+	ErrUnknownAddress,
+	ErrInsufficientCoins,
+	ErrInvalidCoins,
+	ErrOutOfGas,
+	ErrMemoTooLarge,
 }
 
 func TestCodeType(t *testing.T) {
 	require.True(t, ABCICodeOK.IsOK())
 
-	for _, c := range codeTypes {
+	for tcnum, c := range codeTypes {
 		msg := CodeToDefaultMsg(c)
-		require.False(t, strings.HasPrefix(msg, "Unknown code"))
+		require.NotEqual(t, unknownCodeMsg(c), msg, "Code expected to be known. tc #%d, code %d, msg %s", tcnum, c, msg)
 	}
+
+	msg := CodeToDefaultMsg(CodeOK)
+	require.Equal(t, unknownCodeMsg(CodeOK), msg)
 }
 
 func TestErrFn(t *testing.T) {
 	for i, errFn := range errFns {
 		err := errFn("")
 		codeType := codeTypes[i]
-		require.Equal(t, err.Code(), codeType)
-		require.Equal(t, err.Result().Code, ToABCICode(CodespaceRoot, codeType))
+		require.Equal(t, err.Code(), codeType, "Err function expected to return proper code. tc #%d", i)
+		require.Equal(t, err.Result().Code, ToABCICode(CodespaceRoot, codeType), "Err function expected to return proper ABCICode. tc #%d")
 	}
+
+	require.Equal(t, ABCICodeOK, ToABCICode(CodespaceRoot, CodeOK))
 }
diff --git a/types/gas_test.go b/types/gas_test.go
new file mode 100644
index 000000000..cd2384d12
--- /dev/null
+++ b/types/gas_test.go
@@ -0,0 +1,36 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGasMeter(t *testing.T) {
+	cases := []struct {
+		limit Gas
+		usage []Gas
+	}{
+		{10, []Gas{1, 2, 3, 4}},
+		{1000, []Gas{40, 30, 20, 10, 900}},
+		{100000, []Gas{99999, 1}},
+		{100000000, []Gas{50000000, 40000000, 10000000}},
+		{65535, []Gas{32768, 32767}},
+		{65536, []Gas{32768, 32767, 1}},
+	}
+
+	for tcnum, tc := range cases {
+		meter := NewGasMeter(tc.limit)
+		used := int64(0)
+
+		for unum, usage := range tc.usage {
+			used += usage
+			require.NotPanics(t, func() { meter.ConsumeGas(usage, "") }, "Not exceeded limit but panicked. tc #%d, usage #%d", tcnum, unum)
+			require.Equal(t, used, meter.GasConsumed(), "Gas consumption not match. tc #%d, usage #%d", tcnum, unum)
+		}
+
+		require.Panics(t, func() { meter.ConsumeGas(1, "") }, "Exceeded but not panicked. tc #%d", tcnum)
+		break
+
+	}
+}
diff --git a/types/int.go b/types/int.go
index 0227203cd..1421a934d 100644
--- a/types/int.go
+++ b/types/int.go
@@ -4,21 +4,13 @@ import (
 	"encoding/json"
 
 	"math/big"
+	"math/rand"
 )
 
 func newIntegerFromString(s string) (*big.Int, bool) {
 	return new(big.Int).SetString(s, 0)
 }
 
-func newIntegerWithDecimal(n int64, dec int) (res *big.Int) {
-	if dec < 0 {
-		return
-	}
-	exp := new(big.Int).Exp(big.NewInt(10), big.NewInt(int64(dec)), nil)
-	i := new(big.Int)
-	return i.Mul(big.NewInt(n), exp)
-}
-
 func equal(i *big.Int, i2 *big.Int) bool { return i.Cmp(i2) == 0 }
 
 func gt(i *big.Int, i2 *big.Int) bool { return i.Cmp(i2) == 1 }
@@ -37,6 +29,8 @@ func mod(i *big.Int, i2 *big.Int) *big.Int { return new(big.Int).Mod(i, i2) }
 
 func neg(i *big.Int) *big.Int { return new(big.Int).Neg(i) }
 
+func random(i *big.Int) *big.Int { return new(big.Int).Rand(rand.New(rand.NewSource(rand.Int63())), i) }
+
 func min(i *big.Int, i2 *big.Int) *big.Int {
 	if i.Cmp(i2) == 1 {
 		return new(big.Int).Set(i2)
@@ -118,7 +112,13 @@ func NewIntFromString(s string) (res Int, ok bool) {
 // NewIntWithDecimal constructs Int with decimal
 // Result value is n*10^dec
 func NewIntWithDecimal(n int64, dec int) Int {
-	i := newIntegerWithDecimal(n, dec)
+	if dec < 0 {
+		panic("NewIntWithDecimal() decimal is negative")
+	}
+	exp := new(big.Int).Exp(big.NewInt(10), big.NewInt(int64(dec)), nil)
+	i := new(big.Int)
+	i.Mul(big.NewInt(n), exp)
+
 	// Check overflow
 	if i.BitLen() > 255 {
 		panic("NewIntWithDecimal() out of bound")
@@ -141,6 +141,11 @@ func (i Int) Int64() int64 {
 	return i.i.Int64()
 }
 
+// IsInt64 returns true if Int64() not panics
+func (i Int) IsInt64() bool {
+	return i.i.IsInt64()
+}
+
 // IsZero returns true if Int is zero
 func (i Int) IsZero() bool {
 	return i.i.Sign() == 0
@@ -229,6 +234,19 @@ func (i Int) DivRaw(i2 int64) Int {
 	return i.Div(NewInt(i2))
 }
 
+// Mod returns remainder after dividing with Int
+func (i Int) Mod(i2 Int) Int {
+	if i2.Sign() == 0 {
+		panic("division-by-zero")
+	}
+	return Int{mod(i.i, i2.i)}
+}
+
+// ModRaw returns remainder after dividing with int64
+func (i Int) ModRaw(i2 int64) Int {
+	return i.Mod(NewInt(i2))
+}
+
 // Neg negates Int
 func (i Int) Neg() (res Int) {
 	return Int{neg(i.i)}
@@ -239,10 +257,16 @@ func MinInt(i1, i2 Int) Int {
 	return Int{min(i1.BigInt(), i2.BigInt())}
 }
 
+// Human readable string
 func (i Int) String() string {
 	return i.i.String()
 }
 
+// Testing purpose random Int generator
+func randomInt(i Int) Int {
+	return NewIntFromBigInt(random(i.BigInt()))
+}
+
 // MarshalAmino defines custom encoding scheme
 func (i Int) MarshalAmino() (string, error) {
 	if i.i == nil { // Necessary since default Uint initialization has i.i as nil
@@ -319,8 +343,14 @@ func NewUintFromString(s string) (res Uint, ok bool) {
 
 // NewUintWithDecimal constructs Uint with decimal
 // Result value is n*10^dec
-func NewUintWithDecimal(n int64, dec int) Uint {
-	i := newIntegerWithDecimal(n, dec)
+func NewUintWithDecimal(n uint64, dec int) Uint {
+	if dec < 0 {
+		panic("NewUintWithDecimal() decimal is negative")
+	}
+	exp := new(big.Int).Exp(big.NewInt(10), big.NewInt(int64(dec)), nil)
+	i := new(big.Int)
+	i.Mul(new(big.Int).SetUint64(n), exp)
+
 	// Check overflow
 	if i.Sign() == -1 || i.Sign() == 1 && i.BitLen() > 256 {
 		panic("NewUintWithDecimal() out of bound")
@@ -343,6 +373,11 @@ func (i Uint) Uint64() uint64 {
 	return i.i.Uint64()
 }
 
+// IsUint64 returns true if Uint64() not panics
+func (i Uint) IsUint64() bool {
+	return i.i.IsUint64()
+}
+
 // IsZero returns true if Uint is zero
 func (i Uint) IsZero() bool {
 	return i.i.Sign() == 0
@@ -378,7 +413,7 @@ func (i Uint) Add(i2 Uint) (res Uint) {
 	return
 }
 
-// AddRaw adds int64 to Uint
+// AddRaw adds uint64 to Uint
 func (i Uint) AddRaw(i2 uint64) Uint {
 	return i.Add(NewUint(i2))
 }
@@ -393,7 +428,7 @@ func (i Uint) Sub(i2 Uint) (res Uint) {
 	return
 }
 
-// SubRaw subtracts int64 from Uint
+// SubRaw subtracts uint64 from Uint
 func (i Uint) SubRaw(i2 uint64) Uint {
 	return i.Sub(NewUint(i2))
 }
@@ -412,7 +447,7 @@ func (i Uint) Mul(i2 Uint) (res Uint) {
 	return
 }
 
-// MulRaw multipies Uint and int64
+// MulRaw multipies Uint and uint64
 func (i Uint) MulRaw(i2 uint64) Uint {
 	return i.Mul(NewUint(i2))
 }
@@ -426,16 +461,39 @@ func (i Uint) Div(i2 Uint) (res Uint) {
 	return Uint{div(i.i, i2.i)}
 }
 
-// Div divides Uint with int64
+// Div divides Uint with uint64
 func (i Uint) DivRaw(i2 uint64) Uint {
 	return i.Div(NewUint(i2))
 }
 
+// Mod returns remainder after dividing with Uint
+func (i Uint) Mod(i2 Uint) Uint {
+	if i2.Sign() == 0 {
+		panic("division-by-zero")
+	}
+	return Uint{mod(i.i, i2.i)}
+}
+
+// ModRaw returns remainder after dividing with uint64
+func (i Uint) ModRaw(i2 uint64) Uint {
+	return i.Mod(NewUint(i2))
+}
+
 // Return the minimum of the Uints
 func MinUint(i1, i2 Uint) Uint {
 	return Uint{min(i1.BigInt(), i2.BigInt())}
 }
 
+// Human readable string
+func (i Uint) String() string {
+	return i.i.String()
+}
+
+// Testing purpose random Uint generator
+func randomUint(i Uint) Uint {
+	return NewUintFromBigInt(random(i.BigInt()))
+}
+
 // MarshalAmino defines custom encoding scheme
 func (i Uint) MarshalAmino() (string, error) {
 	if i.i == nil { // Necessary since default Uint initialization has i.i as nil
diff --git a/types/int_test.go b/types/int_test.go
index e81bd6d7e..a105bb379 100644
--- a/types/int_test.go
+++ b/types/int_test.go
@@ -1,8 +1,10 @@
 package types
 
 import (
+	"math"
 	"math/big"
 	"math/rand"
+	"strconv"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -15,7 +17,7 @@ func TestFromInt64(t *testing.T) {
 	}
 }
 
-func TestInt(t *testing.T) {
+func TestIntPanic(t *testing.T) {
 	// Max Int = 2^255-1 = 5.789e+76
 	// Min Int = -(2^255-1) = -5.789e+76
 	require.NotPanics(t, func() { NewIntWithDecimal(1, 76) })
@@ -71,7 +73,7 @@ func TestInt(t *testing.T) {
 	require.Panics(t, func() { i1.Div(NewInt(0)) })
 }
 
-func TestUint(t *testing.T) {
+func TestUintPanic(t *testing.T) {
 	// Max Uint = 1.15e+77
 	// Min Uint = 0
 	require.NotPanics(t, func() { NewUintWithDecimal(5, 76) })
@@ -109,3 +111,482 @@ func TestUint(t *testing.T) {
 	// Division-by-zero check
 	require.Panics(t, func() { i1.Div(uintmin) })
 }
+
+// Tests below uses randomness
+// Since we are using *big.Int as underlying value
+// and (U/)Int is immutable value(see TestImmutability(U/)Int)
+// it is safe to use randomness in the tests
+func TestIdentInt(t *testing.T) {
+	for d := 0; d < 1000; d++ {
+		n := rand.Int63()
+		i := NewInt(n)
+
+		ifromstr, ok := NewIntFromString(strconv.FormatInt(n, 10))
+		require.True(t, ok)
+
+		cases := []int64{
+			i.Int64(),
+			i.BigInt().Int64(),
+			ifromstr.Int64(),
+			NewIntFromBigInt(big.NewInt(n)).Int64(),
+			NewIntWithDecimal(n, 0).Int64(),
+		}
+
+		for tcnum, tc := range cases {
+			require.Equal(t, n, tc, "Int is modified during conversion. tc #%d", tcnum)
+		}
+	}
+}
+
+func minint(i1, i2 int64) int64 {
+	if i1 < i2 {
+		return i1
+	}
+	return i2
+}
+
+func TestArithInt(t *testing.T) {
+	for d := 0; d < 1000; d++ {
+		n1 := int64(rand.Int31())
+		i1 := NewInt(n1)
+		n2 := int64(rand.Int31())
+		i2 := NewInt(n2)
+
+		cases := []struct {
+			ires Int
+			nres int64
+		}{
+			{i1.Add(i2), n1 + n2},
+			{i1.Sub(i2), n1 - n2},
+			{i1.Mul(i2), n1 * n2},
+			{i1.Div(i2), n1 / n2},
+			{i1.AddRaw(n2), n1 + n2},
+			{i1.SubRaw(n2), n1 - n2},
+			{i1.MulRaw(n2), n1 * n2},
+			{i1.DivRaw(n2), n1 / n2},
+			{MinInt(i1, i2), minint(n1, n2)},
+			{i1.Neg(), -n1},
+		}
+
+		for tcnum, tc := range cases {
+			require.Equal(t, tc.nres, tc.ires.Int64(), "Int arithmetic operation does not match with int64 operation. tc #%d", tcnum)
+		}
+	}
+
+}
+
+func TestCompInt(t *testing.T) {
+	for d := 0; d < 1000; d++ {
+		n1 := int64(rand.Int31())
+		i1 := NewInt(n1)
+		n2 := int64(rand.Int31())
+		i2 := NewInt(n2)
+
+		cases := []struct {
+			ires bool
+			nres bool
+		}{
+			{i1.Equal(i2), n1 == n2},
+			{i1.GT(i2), n1 > n2},
+			{i1.LT(i2), n1 < n2},
+		}
+
+		for tcnum, tc := range cases {
+			require.Equal(t, tc.nres, tc.ires, "Int comparison operation does not match with int64 operation. tc #%d", tcnum)
+		}
+	}
+}
+
+func TestIdentUint(t *testing.T) {
+	for d := 0; d < 1000; d++ {
+		n := rand.Uint64()
+		i := NewUint(n)
+
+		ifromstr, ok := NewUintFromString(strconv.FormatUint(n, 10))
+		require.True(t, ok)
+
+		cases := []uint64{
+			i.Uint64(),
+			i.BigInt().Uint64(),
+			ifromstr.Uint64(),
+			NewUintFromBigInt(new(big.Int).SetUint64(n)).Uint64(),
+			NewUintWithDecimal(n, 0).Uint64(),
+		}
+
+		for tcnum, tc := range cases {
+			require.Equal(t, n, tc, "Uint is modified during conversion. tc #%d", tcnum)
+		}
+	}
+}
+
+func minuint(i1, i2 uint64) uint64 {
+	if i1 < i2 {
+		return i1
+	}
+	return i2
+}
+
+func TestArithUint(t *testing.T) {
+	for d := 0; d < 1000; d++ {
+		n1 := uint64(rand.Uint32())
+		i1 := NewUint(n1)
+		n2 := uint64(rand.Uint32())
+		i2 := NewUint(n2)
+
+		cases := []struct {
+			ires Uint
+			nres uint64
+		}{
+			{i1.Add(i2), n1 + n2},
+			{i1.Mul(i2), n1 * n2},
+			{i1.Div(i2), n1 / n2},
+			{i1.AddRaw(n2), n1 + n2},
+			{i1.MulRaw(n2), n1 * n2},
+			{i1.DivRaw(n2), n1 / n2},
+			{MinUint(i1, i2), minuint(n1, n2)},
+		}
+
+		for tcnum, tc := range cases {
+			require.Equal(t, tc.nres, tc.ires.Uint64(), "Uint arithmetic operation does not match with uint64 operation. tc #%d", tcnum)
+		}
+
+		if n2 > n1 {
+			continue
+		}
+
+		subs := []struct {
+			ires Uint
+			nres uint64
+		}{
+			{i1.Sub(i2), n1 - n2},
+			{i1.SubRaw(n2), n1 - n2},
+		}
+
+		for tcnum, tc := range subs {
+			require.Equal(t, tc.nres, tc.ires.Uint64(), "Uint subtraction does not match with uint64 operation. tc #%d", tcnum)
+		}
+	}
+}
+
+func TestCompUint(t *testing.T) {
+	for d := 0; d < 1000; d++ {
+		n1 := rand.Uint64()
+		i1 := NewUint(n1)
+		n2 := rand.Uint64()
+		i2 := NewUint(n2)
+
+		cases := []struct {
+			ires bool
+			nres bool
+		}{
+			{i1.Equal(i2), n1 == n2},
+			{i1.GT(i2), n1 > n2},
+			{i1.LT(i2), n1 < n2},
+		}
+
+		for tcnum, tc := range cases {
+			require.Equal(t, tc.nres, tc.ires, "Uint comparison operation does not match with uint64 operation. tc #%d", tcnum)
+		}
+	}
+}
+
+func randint() Int {
+	return NewInt(rand.Int63())
+}
+
+func TestImmutabilityAllInt(t *testing.T) {
+	ops := []func(*Int){
+		func(i *Int) { _ = i.Add(randint()) },
+		func(i *Int) { _ = i.Sub(randint()) },
+		func(i *Int) { _ = i.Mul(randint()) },
+		func(i *Int) { _ = i.Div(randint()) },
+		func(i *Int) { _ = i.AddRaw(rand.Int63()) },
+		func(i *Int) { _ = i.SubRaw(rand.Int63()) },
+		func(i *Int) { _ = i.MulRaw(rand.Int63()) },
+		func(i *Int) { _ = i.DivRaw(rand.Int63()) },
+		func(i *Int) { _ = i.Neg() },
+		func(i *Int) { _ = i.IsZero() },
+		func(i *Int) { _ = i.Sign() },
+		func(i *Int) { _ = i.Equal(randint()) },
+		func(i *Int) { _ = i.GT(randint()) },
+		func(i *Int) { _ = i.LT(randint()) },
+		func(i *Int) { _ = i.String() },
+	}
+
+	for i := 0; i < 1000; i++ {
+		n := rand.Int63()
+		ni := NewInt(n)
+
+		for opnum, op := range ops {
+			op(&ni)
+
+			require.Equal(t, n, ni.Int64(), "Int is modified by operation. tc #%d", opnum)
+			require.Equal(t, NewInt(n), ni, "Int is modified by operation. tc #%d", opnum)
+		}
+	}
+}
+
+type intop func(Int, *big.Int) (Int, *big.Int)
+
+func intarith(uifn func(Int, Int) Int, bifn func(*big.Int, *big.Int, *big.Int) *big.Int) intop {
+	return func(ui Int, bi *big.Int) (Int, *big.Int) {
+		r := rand.Int63()
+		br := new(big.Int).SetInt64(r)
+		return uifn(ui, NewInt(r)), bifn(new(big.Int), bi, br)
+	}
+}
+
+func intarithraw(uifn func(Int, int64) Int, bifn func(*big.Int, *big.Int, *big.Int) *big.Int) intop {
+	return func(ui Int, bi *big.Int) (Int, *big.Int) {
+		r := rand.Int63()
+		br := new(big.Int).SetInt64(r)
+		return uifn(ui, r), bifn(new(big.Int), bi, br)
+	}
+}
+
+func TestImmutabilityArithInt(t *testing.T) {
+	size := 1000
+
+	ops := []intop{
+		intarith(Int.Add, (*big.Int).Add),
+		intarith(Int.Sub, (*big.Int).Sub),
+		intarith(Int.Mul, (*big.Int).Mul),
+		intarith(Int.Div, (*big.Int).Div),
+		intarithraw(Int.AddRaw, (*big.Int).Add),
+		intarithraw(Int.SubRaw, (*big.Int).Sub),
+		intarithraw(Int.MulRaw, (*big.Int).Mul),
+		intarithraw(Int.DivRaw, (*big.Int).Div),
+	}
+
+	for i := 0; i < 1000; i++ {
+		uis := make([]Int, size)
+		bis := make([]*big.Int, size)
+
+		n := rand.Int63()
+		ui := NewInt(n)
+		bi := new(big.Int).SetInt64(n)
+
+		for j := 0; j < size; j++ {
+			op := ops[rand.Intn(len(ops))]
+			uis[j], bis[j] = op(ui, bi)
+		}
+
+		for j := 0; j < size; j++ {
+			require.Equal(t, 0, bis[j].Cmp(uis[j].BigInt()), "Int is different from *big.Int. tc #%d, Int %s, *big.Int %s", j, uis[j].String(), bis[j].String())
+			require.Equal(t, NewIntFromBigInt(bis[j]), uis[j], "Int is different from *big.Int. tc #%d, Int %s, *big.Int %s", j, uis[j].String(), bis[j].String())
+			require.True(t, uis[j].i != bis[j], "Pointer addresses are equal. tc #%d, Int %s, *big.Int %s", j, uis[j].String(), bis[j].String())
+		}
+	}
+}
+func TestImmutabilityAllUint(t *testing.T) {
+	ops := []func(*Uint){
+		func(i *Uint) { _ = i.Add(NewUint(rand.Uint64())) },
+		func(i *Uint) { _ = i.Sub(NewUint(rand.Uint64() % i.Uint64())) },
+		func(i *Uint) { _ = i.Mul(randuint()) },
+		func(i *Uint) { _ = i.Div(randuint()) },
+		func(i *Uint) { _ = i.AddRaw(rand.Uint64()) },
+		func(i *Uint) { _ = i.SubRaw(rand.Uint64() % i.Uint64()) },
+		func(i *Uint) { _ = i.MulRaw(rand.Uint64()) },
+		func(i *Uint) { _ = i.DivRaw(rand.Uint64()) },
+		func(i *Uint) { _ = i.IsZero() },
+		func(i *Uint) { _ = i.Sign() },
+		func(i *Uint) { _ = i.Equal(randuint()) },
+		func(i *Uint) { _ = i.GT(randuint()) },
+		func(i *Uint) { _ = i.LT(randuint()) },
+		func(i *Uint) { _ = i.String() },
+	}
+
+	for i := 0; i < 1000; i++ {
+		n := rand.Uint64()
+		ni := NewUint(n)
+
+		for opnum, op := range ops {
+			op(&ni)
+
+			require.Equal(t, n, ni.Uint64(), "Uint is modified by operation. #%d", opnum)
+			require.Equal(t, NewUint(n), ni, "Uint is modified by operation. #%d", opnum)
+		}
+	}
+}
+
+type uintop func(Uint, *big.Int) (Uint, *big.Int)
+
+func uintarith(uifn func(Uint, Uint) Uint, bifn func(*big.Int, *big.Int, *big.Int) *big.Int, sub bool) uintop {
+	return func(ui Uint, bi *big.Int) (Uint, *big.Int) {
+		r := rand.Uint64()
+		if sub && ui.IsUint64() {
+			if ui.IsZero() {
+				return ui, bi
+			}
+			r = r % ui.Uint64()
+		}
+		ur := NewUint(r)
+		br := new(big.Int).SetUint64(r)
+		return uifn(ui, ur), bifn(new(big.Int), bi, br)
+	}
+}
+
+func uintarithraw(uifn func(Uint, uint64) Uint, bifn func(*big.Int, *big.Int, *big.Int) *big.Int, sub bool) uintop {
+	return func(ui Uint, bi *big.Int) (Uint, *big.Int) {
+		r := rand.Uint64()
+		if sub && ui.IsUint64() {
+			if ui.IsZero() {
+				return ui, bi
+			}
+			r = r % ui.Uint64()
+		}
+		br := new(big.Int).SetUint64(r)
+		mui := ui.ModRaw(math.MaxUint64)
+		mbi := new(big.Int).Mod(bi, new(big.Int).SetUint64(math.MaxUint64))
+		return uifn(mui, r), bifn(new(big.Int), mbi, br)
+	}
+}
+
+func TestImmutabilityArithUint(t *testing.T) {
+	size := 1000
+
+	ops := []uintop{
+		uintarith(Uint.Add, (*big.Int).Add, false),
+		uintarith(Uint.Sub, (*big.Int).Sub, true),
+		uintarith(Uint.Mul, (*big.Int).Mul, false),
+		uintarith(Uint.Div, (*big.Int).Div, false),
+		uintarithraw(Uint.AddRaw, (*big.Int).Add, false),
+		uintarithraw(Uint.SubRaw, (*big.Int).Sub, true),
+		uintarithraw(Uint.MulRaw, (*big.Int).Mul, false),
+		uintarithraw(Uint.DivRaw, (*big.Int).Div, false),
+	}
+
+	for i := 0; i < 1000; i++ {
+		uis := make([]Uint, size)
+		bis := make([]*big.Int, size)
+
+		n := rand.Uint64()
+		ui := NewUint(n)
+		bi := new(big.Int).SetUint64(n)
+
+		for j := 0; j < size; j++ {
+			op := ops[rand.Intn(len(ops))]
+			uis[j], bis[j] = op(ui, bi)
+		}
+
+		for j := 0; j < size; j++ {
+			require.Equal(t, 0, bis[j].Cmp(uis[j].BigInt()), "Int is different from *big.Int. tc #%d, Int %s, *big.Int %s", j, uis[j].String(), bis[j].String())
+			require.Equal(t, NewUintFromBigInt(bis[j]), uis[j], "Int is different from *big.Int. tc #%d, Int %s, *big.Int %s", j, uis[j].String(), bis[j].String())
+			require.True(t, uis[j].i != bis[j], "Pointer addresses are equal. tc #%d, Int %s, *big.Int %s", j, uis[j].String(), bis[j].String())
+		}
+	}
+}
+
+func randuint() Uint {
+	return NewUint(rand.Uint64())
+}
+
+func TestEncodingRandom(t *testing.T) {
+	for i := 0; i < 1000; i++ {
+		n := rand.Int63()
+		ni := NewInt(n)
+		var ri Int
+
+		str, err := ni.MarshalAmino()
+		require.Nil(t, err)
+		err = (&ri).UnmarshalAmino(str)
+		require.Nil(t, err)
+
+		require.Equal(t, ni, ri, "MarshalAmino * UnmarshalAmino is not identity. tc #%d, Expected %s, Actual %s", i, ni.String(), ri.String())
+		require.True(t, ni.i != ri.i, "Pointer addresses are equal. tc #%d", i)
+
+		bz, err := ni.MarshalJSON()
+		require.Nil(t, err)
+		err = (&ri).UnmarshalJSON(bz)
+		require.Nil(t, err)
+
+		require.Equal(t, ni, ri, "MarshalJSON * UnmarshalJSON is not identity. tc #%d, Expected %s, Actual %s", i, ni.String(), ri.String())
+		require.True(t, ni.i != ri.i, "Pointer addresses are equal. tc #%d", i)
+	}
+
+	for i := 0; i < 1000; i++ {
+		n := rand.Uint64()
+		ni := NewUint(n)
+		var ri Uint
+
+		str, err := ni.MarshalAmino()
+		require.Nil(t, err)
+		err = (&ri).UnmarshalAmino(str)
+		require.Nil(t, err)
+
+		require.Equal(t, ni, ri, "MarshalAmino * UnmarshalAmino is not identity. tc #%d, Expected %s, Actual %s", i, ni.String(), ri.String())
+		require.True(t, ni.i != ri.i, "Pointer addresses are equal. tc #%d", i)
+
+		bz, err := ni.MarshalJSON()
+		require.Nil(t, err)
+		err = (&ri).UnmarshalJSON(bz)
+		require.Nil(t, err)
+
+		require.Equal(t, ni, ri, "MarshalJSON * UnmarshalJSON is not identity. tc #%d, Expected %s, Actual %s", i, ni.String(), ri.String())
+		require.True(t, ni.i != ri.i, "Pointer addresses are equal. tc #%d", i)
+	}
+}
+
+func TestEncodingTableInt(t *testing.T) {
+	var i Int
+
+	cases := []struct {
+		i   Int
+		bz  []byte
+		str string
+	}{
+		{NewInt(0), []byte("\"0\""), "0"},
+		{NewInt(100), []byte("\"100\""), "100"},
+		{NewInt(51842), []byte("\"51842\""), "51842"},
+		{NewInt(19513368), []byte("\"19513368\""), "19513368"},
+		{NewInt(999999999999), []byte("\"999999999999\""), "999999999999"},
+	}
+
+	for tcnum, tc := range cases {
+		bz, err := tc.i.MarshalJSON()
+		require.Nil(t, err, "Error marshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.bz, bz, "Marshaled value is different from expected. tc #%d", tcnum)
+		err = (&i).UnmarshalJSON(bz)
+		require.Nil(t, err, "Error unmarshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.i, i, "Unmarshaled value is different from expected. tc #%d", tcnum)
+
+		str, err := tc.i.MarshalAmino()
+		require.Nil(t, err, "Error marshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.str, str, "Marshaled value is different from expected. tc #%d", tcnum)
+		err = (&i).UnmarshalAmino(str)
+		require.Nil(t, err, "Error unmarshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.i, i, "Unmarshaled value is different from expected. tc #%d", tcnum)
+	}
+}
+
+func TestEncodingTableUint(t *testing.T) {
+	var i Uint
+
+	cases := []struct {
+		i   Uint
+		bz  []byte
+		str string
+	}{
+		{NewUint(0), []byte("\"0\""), "0"},
+		{NewUint(100), []byte("\"100\""), "100"},
+		{NewUint(51842), []byte("\"51842\""), "51842"},
+		{NewUint(19513368), []byte("\"19513368\""), "19513368"},
+		{NewUint(999999999999), []byte("\"999999999999\""), "999999999999"},
+	}
+
+	for tcnum, tc := range cases {
+		bz, err := tc.i.MarshalJSON()
+		require.Nil(t, err, "Error marshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.bz, bz, "Marshaled value is different from expected. tc #%d", tcnum)
+		err = (&i).UnmarshalJSON(bz)
+		require.Nil(t, err, "Error unmarshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.i, i, "Unmarshaled value is different from expected. tc #%d", tcnum)
+
+		str, err := tc.i.MarshalAmino()
+		require.Nil(t, err, "Error marshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.str, str, "Marshaled value is different from expected. tc #%d", tcnum)
+		err = (&i).UnmarshalAmino(str)
+		require.Nil(t, err, "Error unmarshaling Int. tc #%d, err %s", tcnum, err)
+		require.Equal(t, tc.i, i, "Unmarshaled value is different from expected. tc #%d", tcnum)
+	}
+}
diff --git a/types/lib/linear_test.go b/types/lib/linear_test.go
index b14300a98..2b5a6c405 100644
--- a/types/lib/linear_test.go
+++ b/types/lib/linear_test.go
@@ -31,6 +31,18 @@ func defaultComponents(key sdk.StoreKey) (sdk.Context, *wire.Codec) {
 	return ctx, cdc
 }
 
+func TestNewLinear(t *testing.T) {
+	cdc := wire.NewCodec()
+	require.NotPanics(t, func() { NewLinear(cdc, nil, nil) })
+	require.NotPanics(t, func() { NewLinear(cdc, nil, DefaultLinearKeys()) })
+	require.NotPanics(t, func() { NewLinear(cdc, nil, &LinearKeys{[]byte{0xAA}, []byte{0xBB}, []byte{0xCC}}) })
+
+	require.Panics(t, func() { NewLinear(cdc, nil, &LinearKeys{nil, nil, nil}) })
+	require.Panics(t, func() { NewLinear(cdc, nil, &LinearKeys{[]byte{0xAA}, nil, nil}) })
+	require.Panics(t, func() { NewLinear(cdc, nil, &LinearKeys{nil, []byte{0xBB}, nil}) })
+	require.Panics(t, func() { NewLinear(cdc, nil, &LinearKeys{nil, nil, []byte{0xCC}}) })
+}
+
 func TestList(t *testing.T) {
 	key := sdk.NewKVStoreKey("test")
 	ctx, cdc := defaultComponents(key)
diff --git a/types/rational_test.go b/types/rational_test.go
index 5ca1ac9c6..940de23dc 100644
--- a/types/rational_test.go
+++ b/types/rational_test.go
@@ -2,6 +2,7 @@ package types
 
 import (
 	"math/big"
+	"math/rand"
 	"testing"
 
 	wire "github.com/cosmos/cosmos-sdk/wire"
@@ -317,3 +318,85 @@ func TestStringOverflow(t *testing.T) {
 		rat3.String(),
 	)
 }
+
+// Tests below uses randomness
+// Since we are using *big.Rat as underlying value
+// and (U/)Int is immutable value(see TestImmutability(U/)Int)
+// it is safe to use randomness in the tests
+func TestArithRat(t *testing.T) {
+	for i := 0; i < 20; i++ {
+		n1 := NewInt(int64(rand.Int31()))
+		d1 := NewInt(int64(rand.Int31()))
+		rat1 := NewRatFromInt(n1, d1)
+
+		n2 := NewInt(int64(rand.Int31()))
+		d2 := NewInt(int64(rand.Int31()))
+		rat2 := NewRatFromInt(n2, d2)
+
+		n1d2 := n1.Mul(d2)
+		n2d1 := n2.Mul(d1)
+
+		cases := []struct {
+			nres Int
+			dres Int
+			rres Rat
+		}{
+			{n1d2.Add(n2d1), d1.Mul(d2), rat1.Add(rat2)},
+			{n1d2.Sub(n2d1), d1.Mul(d2), rat1.Sub(rat2)},
+			{n1.Mul(n2), d1.Mul(d2), rat1.Mul(rat2)},
+			{n1d2, n2d1, rat1.Quo(rat2)},
+		}
+
+		for _, tc := range cases {
+			require.Equal(t, NewRatFromInt(tc.nres, tc.dres), tc.rres)
+		}
+	}
+}
+
+func TestCompRat(t *testing.T) {
+	for i := 0; i < 20; i++ {
+		n1 := NewInt(int64(rand.Int31()))
+		d1 := NewInt(int64(rand.Int31()))
+		rat1 := NewRatFromInt(n1, d1)
+
+		n2 := NewInt(int64(rand.Int31()))
+		d2 := NewInt(int64(rand.Int31()))
+		rat2 := NewRatFromInt(n2, d2)
+
+		n1d2 := n1.Mul(d2)
+		n2d1 := n2.Mul(d1)
+
+		cases := []struct {
+			ires bool
+			rres bool
+		}{
+			{n1d2.Equal(n2d1), rat1.Equal(rat2)},
+			{n1d2.GT(n2d1), rat1.GT(rat2)},
+			{n1d2.LT(n2d1), rat1.LT(rat2)},
+			{n1d2.GT(n2d1) || n1d2.Equal(n2d1), rat1.GTE(rat2)},
+			{n1d2.LT(n2d1) || n1d2.Equal(n2d1), rat1.LTE(rat2)},
+		}
+
+		for _, tc := range cases {
+			require.Equal(t, tc.ires, tc.rres)
+		}
+	}
+}
+
+func TestImmutabilityRat(t *testing.T) {
+	for i := 0; i < 20; i++ {
+		n := int64(rand.Int31())
+		r := NewRat(n)
+		z := ZeroRat()
+		o := OneRat()
+
+		r.Add(z)
+		r.Sub(z)
+		r.Mul(o)
+		r.Quo(o)
+
+		require.Equal(t, n, r.RoundInt64())
+		require.True(t, NewRat(n).Equal(r))
+	}
+
+}
diff --git a/types/result_test.go b/types/result_test.go
new file mode 100644
index 000000000..e0305932c
--- /dev/null
+++ b/types/result_test.go
@@ -0,0 +1,18 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestResult(t *testing.T) {
+	var res Result
+	require.True(t, res.IsOK())
+
+	res.Data = []byte("data")
+	require.True(t, res.IsOK())
+
+	res.Code = ABCICodeType(1)
+	require.False(t, res.IsOK())
+}
diff --git a/types/store_test.go b/types/store_test.go
index f376f3be1..b5e36c487 100644
--- a/types/store_test.go
+++ b/types/store_test.go
@@ -25,3 +25,15 @@ func TestPrefixEndBytes(t *testing.T) {
 		require.Equal(t, test.expected, end)
 	}
 }
+
+func TestCommitID(t *testing.T) {
+	var empty CommitID
+	require.True(t, empty.IsZero())
+
+	var nonempty CommitID
+	nonempty = CommitID{
+		Version: 1,
+		Hash:    []byte("testhash"),
+	}
+	require.False(t, nonempty.IsZero())
+}
diff --git a/types/tags_test.go b/types/tags_test.go
index 4ef556124..77bb4041c 100644
--- a/types/tags_test.go
+++ b/types/tags_test.go
@@ -11,6 +11,7 @@ func TestAppendTags(t *testing.T) {
 	b := NewTags("b", []byte("2"))
 	c := a.AppendTags(b)
 	require.Equal(t, c, Tags{MakeTag("a", []byte("1")), MakeTag("b", []byte("2"))})
+	require.Equal(t, c, Tags{MakeTag("a", []byte("1"))}.AppendTag("b", []byte("2")))
 }
 
 func TestEmptyTags(t *testing.T) {
@@ -21,4 +22,14 @@ func TestEmptyTags(t *testing.T) {
 func TestNewTags(t *testing.T) {
 	b := NewTags("a", []byte("1"))
 	require.Equal(t, b, Tags{MakeTag("a", []byte("1"))})
+
+	require.Panics(t, func() { NewTags("a", []byte("1"), "b") })
+	require.Panics(t, func() { NewTags("a", 1) })
+	require.Panics(t, func() { NewTags(1, 1) })
+	require.Panics(t, func() { NewTags(true, false) })
+}
+
+func TestKVPairTags(t *testing.T) {
+	a := NewTags("a", []byte("1"))
+	require.Equal(t, a, Tags(a.ToKVPairs()))
 }
diff --git a/types/utils_test.go b/types/utils_test.go
index af22f2db6..05bc622e7 100644
--- a/types/utils_test.go
+++ b/types/utils_test.go
@@ -31,9 +31,15 @@ func TestSortJSON(t *testing.T) {
 
 	for tcIndex, tc := range cases {
 		got, err := SortJSON([]byte(tc.unsortedJSON))
-		if tc.wantErr != (err != nil) {
-			t.Fatalf("got %t, want: %t, tc #%d, err=%s", err != nil, tc.wantErr, tcIndex, err)
+		if tc.wantErr {
+			require.NotNil(t, err, "tc #%d", tcIndex)
+			require.Panics(t, func() { MustSortJSON([]byte(tc.unsortedJSON)) })
+		} else {
+			require.Nil(t, err, "tc #%d, err=%s", tcIndex, err)
+			require.NotPanics(t, func() { MustSortJSON([]byte(tc.unsortedJSON)) })
+			require.Equal(t, got, MustSortJSON([]byte(tc.unsortedJSON)))
 		}
+
 		require.Equal(t, string(got), tc.want)
 	}
 }