Add Linters

.golangci.yml

@@ -9,23 +9,46 @@ run:
 
 linters:
   enable:
-  - whitespace
-  - gosec
+  - whitespace # Tool for detection of leading and trailing whitespace
+  - gosec # Security problems
   - gci
-  - misspell
+  - misspell # Misspelled English words in comments
   - gomnd
-  - gofmt
-  - goimports
+  - gofmt # Whether the code was gofmt-ed
+  - goimports # Unused imports
   - revive
+  - wastedassign # Finds wasted assignment statements
+  - unconvert # Unnecessary type conversions
+  - prealloc # Finds slice declarations that could potentially be pre-allocated
+  - predeclared # Finds code that shadows one of Go's predeclared identifiers
+  - nolintlint # Ill-formed or insufficient nolint directives
+  - makezero # Finds slice declarations with non-zero initial length
+  - importas # Enforces consistent import aliases
+  - dogsled # Checks assignments with too many blank identifiers (e.g. x, , , _, := f())
+  - errname # Checks that sentinel errors are prefixed with the Err and error types are suffixed with the Error
+  - goconst # Repeated strings that could be replaced by a constant
+  - forcetypeassert # Finds forced type assertions
+  - tparallel # Detects inappropriate usage of t.Parallel() method in your Go test codes
+  - thelper # Detects golang test helpers without t.Helper() call and checks the consistency of test helpers
+  - errcheck # Errcheck is a go lint rule for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases
+  - lll # Long lines
 
 linters-settings:
   revive:
     rules:
     - name: exported
       arguments:
       - disableStutteringCheck
+  goconst:
+    min-len: 4
+    min-occurrences: 3
 
 issues:
+  exclude-rules:
+      - path: _test\.go
+        linters:
+          - gosec
+          - lll
   include:
   - EXC0012  # EXC0012 revive: Annoying issue about not having a comment. The rare codebase has such comments
   - EXC0014  # EXC0014 revive: Annoying issue about not having a comment. The rare codebase has such comments

client/client_test.go

@@ -17,6 +17,8 @@ import (
 )
 
 func TestClient_GetStatus(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name       string
 		result     string
@@ -80,6 +82,8 @@ func TestClient_GetStatus(t *testing.T) {
 }
 
 func TestClient_SignSequence(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name       string
 		ss         types.SignedSequence
@@ -163,6 +167,8 @@ func TestClient_SignSequence(t *testing.T) {
 }
 
 func TestClient_GetOffChainData(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name       string
 		hash       common.Hash
@@ -234,6 +240,8 @@ func TestClient_GetOffChainData(t *testing.T) {
 }
 
 func TestClient_ListOffChainData(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name       string
 		hashes     []common.Hash

config/config.go

@@ -75,7 +75,12 @@ func Load(ctx *cli.Context) (*Config, error) {
 
 	decodeHooks := []viper.DecoderConfigOption{
 		// this allows arrays to be decoded from env var separated by ",", example: MY_VAR="value1,value2,value3"
-		viper.DecodeHook(mapstructure.ComposeDecodeHookFunc(mapstructure.TextUnmarshallerHookFunc(), mapstructure.StringToSliceHookFunc(","))),
+		viper.DecodeHook(
+			mapstructure.ComposeDecodeHookFunc(
+				mapstructure.TextUnmarshallerHookFunc(),
+				mapstructure.StringToSliceHookFunc(","),
+			),
+		),
 	}
 	err = viper.Unmarshal(&cfg, decodeHooks...)
 	return cfg, err

db/db_test.go

@@ -14,6 +14,8 @@ import (
 )
 
 func Test_DB_StoreLastProcessedBlock(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		task      string
@@ -69,6 +71,8 @@ func Test_DB_StoreLastProcessedBlock(t *testing.T) {
 }
 
 func Test_DB_GetLastProcessedBlock(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		task      string
@@ -133,6 +137,8 @@ func Test_DB_GetLastProcessedBlock(t *testing.T) {
 }
 
 func Test_DB_StoreUnresolvedBatchKeys(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		bk        []types.BatchKey
@@ -212,6 +218,8 @@ func Test_DB_StoreUnresolvedBatchKeys(t *testing.T) {
 }
 
 func Test_DB_GetUnresolvedBatchKeys(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		bks       []types.BatchKey
@@ -277,6 +285,8 @@ func Test_DB_GetUnresolvedBatchKeys(t *testing.T) {
 }
 
 func Test_DB_DeleteUnresolvedBatchKeys(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		bks       []types.BatchKey
@@ -343,6 +353,8 @@ func Test_DB_DeleteUnresolvedBatchKeys(t *testing.T) {
 }
 
 func Test_DB_StoreOffChainData(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		od        []types.OffChainData
@@ -422,6 +434,8 @@ func Test_DB_StoreOffChainData(t *testing.T) {
 }
 
 func Test_DB_GetOffChainData(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		od        []types.OffChainData
@@ -505,6 +519,8 @@ func Test_DB_GetOffChainData(t *testing.T) {
 }
 
 func Test_DB_ListOffChainData(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		od        []types.OffChainData
@@ -638,6 +654,8 @@ func Test_DB_ListOffChainData(t *testing.T) {
 }
 
 func Test_DB_CountOffchainData(t *testing.T) {
+	t.Parallel()
+
 	testTable := []struct {
 		name      string
 		od        []types.OffChainData

log/config.go

@@ -3,11 +3,13 @@ package log
 // Config for log
 type Config struct {
 	// Environment defining the log format ("production" or "development").
-	// In development mode enables development mode (which makes DPanicLevel logs panic), uses a console encoder, writes to standard error, and disables sampling. Stacktraces are automatically included on logs of WarnLevel and above.
+	// In development mode enables development mode (which makes DPanicLevel logs panic),
+	// uses a console encoder, writes to standard error, and disables sampling.
+	// Stacktraces are automatically included on logs of WarnLevel and above.
 	// Check [here](https://pkg.go.dev/go.uber.org/zap@v1.24.0#NewDevelopmentConfig)
 	Environment Environment `mapstructure:"Environment" jsonschema:"enum=production,enum=development"`
 	// Level of log. As lower value more logs are going to be generated
-	Level string `mapstructure:"Level" jsonschema:"enum=debug,enum=info,enum=warn,enum=error,enum=dpanic,enum=panic,enum=fatal"`
+	Level string `mapstructure:"Level" jsonschema:"enum=debug,enum=info,enum=warn,enum=error,enum=dpanic,enum=panic,enum=fatal"` //nolint:lll
 	// Outputs
 	Outputs []string `mapstructure:"Outputs"`
 }

log/log.go

@@ -91,7 +91,7 @@ func NewLogger(cfg Config) (*zap.SugaredLogger, *zap.AtomicLevel, error) {
 	if err != nil {
 		return nil, nil, err
 	}
-	defer logger.Sync() //nolint:gosec,errcheck
+	defer logger.Sync() //nolint:errcheck
 
 	// skip 2 callers: one for our wrapper methods and one for the package functions
 	withOptions := logger.WithOptions(zap.AddCallerSkip(2)) //nolint:gomnd

rpc/client_test.go

@@ -13,6 +13,8 @@ import (
 )
 
 func Test_JSONRPCCallWithContext(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name       string
 		result     string

rpc/error.go

@@ -25,8 +25,8 @@ const (
 )
 
 var (
-	// invalidJSONReqErr denotes error that is returned when invalid JSON request is received
-	invalidJSONReqErr = errors.New("Invalid json request")
+	// errInvalidJSONReq denotes error that is returned when invalid JSON request is received
+	errInvalidJSONReq = errors.New("invalid json request")
 )
 
 // Error interface

rpc/handler.go

@@ -123,7 +123,11 @@ func (h *Handler) Handle(req handleRequest) Response {
 	// check params passed by request match function params
 	var testStruct []interface{}
 	if err := json.Unmarshal(req.Params, &testStruct); err == nil && len(testStruct) > fd.numParams() {
-		return NewResponse(req.Request, nil, NewRPCError(InvalidParamsErrorCode, fmt.Sprintf("too many arguments, want at most %d", fd.numParams())))
+		return NewResponse(
+			req.Request,
+			nil,
+			NewRPCError(InvalidParamsErrorCode, fmt.Sprintf("too many arguments, want at most %d", fd.numParams())),
+		)
 	}
 
 	inputs := make([]interface{}, fd.numParams()-inArgsOffset)
@@ -161,7 +165,7 @@ func (h *Handler) HandleWs(reqBody []byte, wsConn *websocket.Conn, httpReq *http
 	log.Debugf("WS message received: %v", string(reqBody))
 	var req Request
 	if err := json.Unmarshal(reqBody, &req); err != nil {
-		return NewResponse(req, nil, NewRPCError(InvalidRequestErrorCode, invalidJSONReqErr.Error())).Bytes()
+		return NewResponse(req, nil, NewRPCError(InvalidRequestErrorCode, errInvalidJSONReq.Error())).Bytes()
 	}
 
 	handleReq := handleRequest{
@@ -254,7 +258,12 @@ func validateFunc(funcName string, fv reflect.Value, isMethod bool) (inNum int,
 		return
 	}
 	if !isRPCErrorType(ft.Out(1)) {
-		err = fmt.Errorf("unexpected type for the second return value of the function '%s': '%s'. Expected '%s'", funcName, ft.Out(1), rpcErrType)
+		err = fmt.Errorf(
+			"unexpected type for the second return value of the function '%s': '%s'. Expected '%s'",
+			funcName,
+			ft.Out(1),
+			rpcErrType,
+		)
 		return
 	}
 

rpc/server.go

@@ -108,7 +108,10 @@ func (s *Server) handle(w http.ResponseWriter, req *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 	w.Header().Set("Access-Control-Allow-Origin", "*")
 	w.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS")
-	w.Header().Set("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
+	w.Header().Set(
+		"Access-Control-Allow-Headers",
+		"Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization",
+	)
 
 	if (*req).Method == "OPTIONS" {
 		// TODO(pg): need to count it in the metrics?
@@ -156,7 +159,7 @@ func (s *Server) isSingleRequest(data []byte) (bool, Error) {
 	x := bytes.TrimLeft(data, " \t\r\n")
 
 	if len(x) == 0 {
-		return false, NewRPCError(InvalidRequestErrorCode, invalidJSONReqErr.Error())
+		return false, NewRPCError(InvalidRequestErrorCode, errInvalidJSONReq.Error())
 	}
 
 	return x[0] == '{', nil
@@ -213,7 +216,7 @@ func (s *Server) parseRequest(data []byte) (Request, error) {
 	var req Request
 
 	if err := json.Unmarshal(data, &req); err != nil {
-		return Request{}, NewRPCError(InvalidRequestErrorCode, invalidJSONReqErr.Error())
+		return Request{}, NewRPCError(InvalidRequestErrorCode, errInvalidJSONReq.Error())
 	}
 
 	return req, nil
@@ -223,7 +226,7 @@ func (s *Server) parseRequests(data []byte) ([]Request, error) {
 	var requests []Request
 
 	if err := json.Unmarshal(data, &requests); err != nil {
-		return nil, NewRPCError(InvalidRequestErrorCode, invalidJSONReqErr.Error())
+		return nil, NewRPCError(InvalidRequestErrorCode, errInvalidJSONReq.Error())
 	}
 
 	return requests, nil

rpc/server_test.go

@@ -120,7 +120,7 @@ func Test_ServerHandleRequest(t *testing.T) {
 		server.handle(respRecorder, httpReq)
 
 		require.Equal(t, http.StatusInternalServerError, respRecorder.Result().StatusCode)
-		require.Equal(t, invalidJSONReqErr.Error(), respRecorder.Body.String())
+		require.Equal(t, errInvalidJSONReq.Error(), respRecorder.Body.String())
 	})
 
 	t.Run("GET method request", func(t *testing.T) {

sequencer/call_test.go

@@ -16,6 +16,8 @@ import (
 )
 
 func Test_GetData(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name         string
 		batchNum     uint64
@@ -72,7 +74,10 @@ func Test_GetData(t *testing.T) {
 				var params []interface{}
 				require.NoError(t, json.Unmarshal(res.Params, &params))
 				require.Equal(t, float64(tt.batchNum), params[0])
-				require.True(t, params[1].(bool))
+
+				boolVal, ok := params[1].(bool)
+				require.True(t, ok, "params[1] is not of type bool")
+				require.True(t, boolVal)
 
 				if tt.statusCode > 0 {
 					w.WriteHeader(tt.statusCode)

services/datacom/datacom.go

@@ -46,7 +46,8 @@ func (d *Endpoints) SignSequence(signedSequence types.SignedSequence) (interface
 
 	// Store off-chain data by hash (hash(L2Data): L2Data)
 	if err = d.db.StoreOffChainData(context.Background(), signedSequence.Sequence.OffChainData()); err != nil {
-		return "0x0", rpc.NewRPCError(rpc.DefaultErrorCode, fmt.Errorf("failed to store offchain data. Error: %w", err).Error())
+		return "0x0", rpc.NewRPCError(rpc.DefaultErrorCode,
+			fmt.Errorf("failed to store offchain data. Error: %w", err).Error())
 	}
 
 	// Sign

services/datacom/datacom_test.go

@@ -40,6 +40,8 @@ func TestDataCom_SignSequence(t *testing.T) {
 	require.NoError(t, err)
 
 	testFn := func(t *testing.T, cfg testConfig) {
+		t.Helper()
+
 		var (
 			signer         = privateKey
 			signedSequence *types.SignedSequence

services/status/status_test.go

@@ -11,6 +11,8 @@ import (
 )
 
 func TestEndpoints_GetStatus(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name                     string
 		countOffchainData        uint64
@@ -60,10 +62,13 @@ func TestEndpoints_GetStatus(t *testing.T) {
 			} else {
 				require.NoError(t, err)
 
-				require.NotEmpty(t, actual.(types.DACStatus).Uptime)
-				require.Equal(t, "v0.1.0", actual.(types.DACStatus).Version)
-				require.Equal(t, tt.countOffchainData, actual.(types.DACStatus).KeyCount)
-				require.Equal(t, tt.getLastProcessedBlock, actual.(types.DACStatus).BackfillProgress)
+				dacStatus, ok := actual.(types.DACStatus)
+				require.True(t, ok, "actual is not of type types.DACStatus")
+
+				require.NotEmpty(t, dacStatus.Uptime)
+				require.Equal(t, "v0.1.0", dacStatus.Version)
+				require.Equal(t, tt.countOffchainData, dacStatus.KeyCount)
+				require.Equal(t, tt.getLastProcessedBlock, dacStatus.BackfillProgress)
 			}
 		})
 	}

services/sync/sync_test.go

@@ -12,6 +12,8 @@ import (
 )
 
 func TestEndpoints_GetOffChainData(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name  string
 		hash  types.ArgHash
@@ -68,6 +70,8 @@ func TestEndpoints_GetOffChainData(t *testing.T) {
 }
 
 func TestSyncEndpoints_ListOffChainData(t *testing.T) {
+	t.Parallel()
+
 	tests := []struct {
 		name   string
 		hashes []types.ArgHash