Fix Empty slice literal used to declare a variable

dot/rpc/modules/childstate_test.go

@@ -124,7 +124,6 @@ func TestChildStateModule_GetKeys(t *testing.T) {
 					Hash: &common.Hash{},
 				},
 			},
-			exp:    []string{},
 			expErr: errors.New("GetStorageChild error"),
 		},
 		{
@@ -138,7 +137,6 @@ func TestChildStateModule_GetKeys(t *testing.T) {
 					Key: []byte(":child_storage_key"),
 				},
 			},
-			exp:    []string{},
 			expErr: errors.New("GetStateRootFromBlock error"),
 		},
 	}
@@ -148,7 +146,7 @@ func TestChildStateModule_GetKeys(t *testing.T) {
 				storageAPI: tt.fields.storageAPI,
 				blockAPI:   tt.fields.blockAPI,
 			}
-			res := []string{}
+			var res []string
 			err := cs.GetKeys(tt.args.in0, tt.args.req, &res)
 			if tt.expErr != nil {
 				assert.EqualError(t, err, tt.expErr.Error())

dot/rpc/modules/system_test.go

@@ -446,14 +446,13 @@ func TestSystemModule_LocalListenAddresses(t *testing.T) {
 			args: args{
 				req: &EmptyRequest{},
 			},
-			exp:    []string{},
 			expErr: errors.New("multiaddress list is empty"),
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			sm := tt.sysModule
-			res := []string{}
+			var res []string
 			err := sm.LocalListenAddresses(tt.args.r, tt.args.req, &res)
 			if tt.expErr != nil {
 				assert.EqualError(t, err, tt.expErr.Error())

dot/types/body.go

@@ -24,12 +24,11 @@ func NewBody(e []Extrinsic) *Body {
 
 // NewBodyFromBytes returns a Body from a SCALE encoded byte array.
 func NewBodyFromBytes(b []byte) (*Body, error) {
-	exts := [][]byte{}
-
 	if len(b) == 0 {
 		return NewBody([]Extrinsic{}), nil
 	}
 
+	var exts [][]byte
 	err := scale.Unmarshal(b, &exts)
 	if err != nil {
 		return nil, err
@@ -59,16 +58,15 @@ func NewBodyFromEncodedBytes(exts [][]byte) (*Body, error) {
 
 // NewBodyFromExtrinsicStrings creates a block body given an array of hex-encoded
 // 0x-prefixed strings.
-func NewBodyFromExtrinsicStrings(ss []string) (*Body, error) {
-	exts := []Extrinsic{}
-	for _, s := range ss {
-		b, err := common.HexToBytes(s)
+func NewBodyFromExtrinsicStrings(ss []string) (body *Body, err error) {
+	exts := make([]Extrinsic, len(ss))
+	for i, s := range ss {
+		exts[i], err = common.HexToBytes(s)
 		if errors.Is(err, common.ErrNoPrefix) {
-			b = []byte(s)
+			exts[i] = []byte(s)
 		} else if err != nil {
 			return nil, err
 		}
-		exts = append(exts, b)
 	}
 
 	return NewBody(exts), nil

dot/types/body_test.go

@@ -4,7 +4,6 @@
 package types
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/ChainSafe/gossamer/lib/common"
@@ -48,14 +47,11 @@ func TestBodyFromEncodedBytes(t *testing.T) {
 }
 
 func TestBodyFromExtrinsicStrings(t *testing.T) {
-	extStrings := []string{}
-
-	for _, ext := range exts {
-		extStrings = append(extStrings, common.BytesToHex(ext))
+	extStrings := make([]string, len(exts))
+	for i := range exts {
+		extStrings[i] = common.BytesToHex(exts[i])
 	}
 
-	fmt.Println(extStrings)
-
 	bodyFromByteExtrinsics := NewBody(exts)
 	bodyFromStringExtrinsics, err := NewBodyFromExtrinsicStrings(extStrings)
 	require.NoError(t, err)

dot/types/grandpa.go

@@ -149,7 +149,7 @@ func EncodeGrandpaVoters(voters GrandpaVoters) ([]byte, error) {
 
 // DecodeGrandpaVoters returns a decoded GrandpaVoters
 func DecodeGrandpaVoters(in []byte) (GrandpaVoters, error) {
-	dec := []voter{}
+	var dec []voter
 	err := scale.Unmarshal(in, &dec)
 	if err != nil {
 		return nil, err

dot/types/grandpa_test.go

@@ -68,7 +68,7 @@ func TestGrandpaAuthoritiesRawToAuthorities(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, exp, enc)
 
-	dec := []GrandpaAuthoritiesRaw{}
+	var dec []GrandpaAuthoritiesRaw
 	err = scale.Unmarshal(enc, &dec)
 	require.NoError(t, err)
 	require.Equal(t, auths, dec)

dot/types/inherents.go

@@ -98,7 +98,7 @@ func (d *InherentData) Encode() ([]byte, error) {
 		return nil, err
 	}
 
-	keys := [][8]byte{}
+	keys := make([][8]byte, 0, len(d.Data))
 	for key := range d.Data {
 		keys = append(keys, key)
 	}

lib/blocktree/leaves.go

@@ -111,7 +111,7 @@ func (lm *leafMap) nodes() []*node {
 	lm.RLock()
 	defer lm.RUnlock()
 
-	nodes := []*node{}
+	var nodes []*node
 
 	lm.smap.Range(func(h, n interface{}) bool {
 		node := n.(*node)

lib/blocktree/node_test.go

@@ -23,7 +23,7 @@ func TestNode_GetLeaves(t *testing.T) {
 	testNode := bt.getNode(branches[0].hash).children[0]
 	leaves := testNode.getLeaves(nil)
 
-	expected := []*node{}
+	var expected []*node
 	for _, lf := range bt.leaves.toMap() {
 		if lf.isDescendantOf(testNode) {
 			expected = append(expected, lf)

lib/common/common.go

@@ -17,9 +17,8 @@ import (
 var ErrNoPrefix = errors.New("could not byteify non 0x prefixed string")
 
 // StringToInts turns a string consisting of ints separated by commas into an int array
-func StringToInts(in string) ([]int, error) {
+func StringToInts(in string) (res []int, err error) {
 	intstrs := strings.Split(in, ",")
-	res := []int{}
 	for _, intstr := range intstrs {
 		i, err := strconv.Atoi(intstr)
 		if err != nil {
@@ -32,18 +31,18 @@ func StringToInts(in string) ([]int, error) {
 
 // StringArrayToBytes turns an array of strings into an array of byte arrays
 func StringArrayToBytes(in []string) [][]byte {
-	b := [][]byte{}
-	for _, str := range in {
-		b = append(b, []byte(str))
+	b := make([][]byte, len(in))
+	for i := range in {
+		b[i] = []byte(in[i])
 	}
 	return b
 }
 
 // BytesToStringArray turns an array of byte arrays into an array strings
 func BytesToStringArray(in [][]byte) []string {
-	strs := []string{}
-	for _, b := range in {
-		strs = append(strs, string(b))
+	strs := make([]string, len(in))
+	for i := range in {
+		strs[i] = string(in[i])
 	}
 	return strs
 }

lib/common/hasher_test.go

@@ -14,7 +14,7 @@ import (
 func TestBlake2b218_EmptyHash(t *testing.T) {
 	// test case from https://github.com/noot/blake2b_test which uses the blake2-rfp rust crate
 	// also see https://github.com/paritytech/substrate/blob/master/core/primitives/src/hashing.rs
-	in := []byte{}
+	var in []byte
 	h, err := common.Blake2b128(in)
 	require.NoError(t, err)
 
@@ -42,7 +42,7 @@ func Test_MustBlake2b8(t *testing.T) {
 func TestBlake2bHash_EmptyHash(t *testing.T) {
 	// test case from https://github.com/noot/blake2b_test which uses the blake2-rfp rust crate
 	// also see https://github.com/paritytech/substrate/blob/master/core/primitives/src/hashing.rs
-	in := []byte{}
+	var in []byte
 	h, err := common.Blake2bHash(in)
 	require.NoError(t, err)
 
@@ -53,7 +53,7 @@ func TestBlake2bHash_EmptyHash(t *testing.T) {
 
 func TestKeccak256_EmptyHash(t *testing.T) {
 	// test case from https://github.com/debris/tiny-keccak/blob/master/tests/keccak.rs#L4
-	in := []byte{}
+	var in []byte
 	h, err := common.Keccak256(in)
 	require.NoError(t, err)
 

lib/keystore/basic_keystore.go

@@ -82,8 +82,7 @@ func (ks *BasicKeystore) GetKeypairFromAddress(pub common.Address) KeyPair {
 }
 
 // PublicKeys returns all public keys in the keystore
-func (ks *BasicKeystore) PublicKeys() []crypto.PublicKey {
-	srkeys := []crypto.PublicKey{}
+func (ks *BasicKeystore) PublicKeys() (srkeys []crypto.PublicKey) {
 	if ks.keys == nil {
 		return srkeys
 	}

lib/keystore/basic_keystore_test.go

@@ -35,7 +35,7 @@ func TestBasicKeystore(t *testing.T) {
 func TestBasicKeystore_PublicKeys(t *testing.T) {
 	ks := NewBasicKeystore("test", crypto.Sr25519Type)
 
-	expectedPubkeys := []crypto.PublicKey{}
+	var expectedPubkeys []crypto.PublicKey
 	numKps := 12
 
 	for i := 0; i < numKps; i++ {

lib/keystore/generic_keystore.go

@@ -73,8 +73,7 @@ func (ks *GenericKeystore) GetKeypairFromAddress(pub common.Address) KeyPair {
 }
 
 // PublicKeys returns all public keys in the keystore
-func (ks *GenericKeystore) PublicKeys() []crypto.PublicKey {
-	srkeys := []crypto.PublicKey{}
+func (ks *GenericKeystore) PublicKeys() (srkeys []crypto.PublicKey) {
 	if ks.keys == nil {
 		return srkeys
 	}
@@ -109,8 +108,7 @@ func (ks *GenericKeystore) NumEd25519Keys() int {
 }
 
 // Ed25519PublicKeys keys
-func (ks *GenericKeystore) Ed25519PublicKeys() []crypto.PublicKey {
-	edkeys := []crypto.PublicKey{}
+func (ks *GenericKeystore) Ed25519PublicKeys() (edkeys []crypto.PublicKey) {
 	if ks.keys == nil {
 		return edkeys
 	}
@@ -138,8 +136,7 @@ func (ks *GenericKeystore) Ed25519Keypairs() (edkeys []KeyPair) {
 }
 
 // Sr25519PublicKeys PublicKey
-func (ks *GenericKeystore) Sr25519PublicKeys() []crypto.PublicKey {
-	srkeys := []crypto.PublicKey{}
+func (ks *GenericKeystore) Sr25519PublicKeys() (srkeys []crypto.PublicKey) {
 	if ks.keys == nil {
 		return srkeys
 	}
@@ -167,8 +164,7 @@ func (ks *GenericKeystore) Sr25519Keypairs() (srkeys []KeyPair) {
 }
 
 // Secp256k1PublicKeys PublicKey
-func (ks *GenericKeystore) Secp256k1PublicKeys() []crypto.PublicKey {
-	sckeys := []crypto.PublicKey{}
+func (ks *GenericKeystore) Secp256k1PublicKeys() (sckeys []crypto.PublicKey) {
 	if ks.keys == nil {
 		return sckeys
 	}

lib/keystore/generic_keystore_test.go

@@ -18,7 +18,7 @@ import (
 func TestGetSr25519PublicKeys(t *testing.T) {
 	ks := NewGenericKeystore("test")
 
-	expectedPubkeys := []crypto.PublicKey{}
+	var expectedPubkeys []crypto.PublicKey
 	numKps := 12
 
 	for i := 0; i < numKps; i++ {
@@ -54,7 +54,7 @@ func TestGetSr25519PublicKeys(t *testing.T) {
 func TestGetEd25519PublicKeys(t *testing.T) {
 	ks := NewGenericKeystore("test")
 
-	expectedPubkeys := []crypto.PublicKey{}
+	var expectedPubkeys []crypto.PublicKey
 	numKps := 10
 
 	for i := 0; i < numKps; i++ {
@@ -90,7 +90,7 @@ func TestGetEd25519PublicKeys(t *testing.T) {
 func TestGetSecp256k1PublicKeys(t *testing.T) {
 	ks := NewGenericKeystore("test")
 
-	expectedPubkeys := []crypto.PublicKey{}
+	var expectedPubkeys []crypto.PublicKey
 	numKps := 10
 
 	for i := 0; i < numKps; i++ {

lib/keystore/helpers_test.go

@@ -217,7 +217,7 @@ func TestImportKey(t *testing.T) {
 func TestListKeys(t *testing.T) {
 	testdir := t.TempDir()
 
-	expected := []string{}
+	var expected []string
 
 	for i := 0; i < 5; i++ {
 		var err error

lib/runtime/wasmer/imports_test.go

@@ -1865,8 +1865,7 @@ func Test_ext_trie_blake2_256_verify_proof_version_1(t *testing.T) {
 			hashEnc, err := scale.Marshal(testcase.root)
 			require.NoError(t, err)
 
-			args := []byte{}
-			args = append(args, hashEnc...)
+			args := hashEnc
 
 			encProof, err := scale.Marshal(testcase.proof)
 			require.NoError(t, err)