all: fix minor style issues, add linters

.golangci.yml

@@ -27,6 +27,8 @@ linters:
     - durationcheck
     - gocheckcompilerdirectives
     - reassign
+    - mirror
+    - tenv
     ### linters we tried and will not be using:
     ###
     # - structcheck # lots of false positives

accounts/abi/bind/bind.go

@@ -252,7 +252,7 @@ func Bind(types []string, abis []string, bytecodes []string, fsigs []map[string]
 		}
 		// Parse library references.
 		for pattern, name := range libs {
-			matched, err := regexp.Match("__\\$"+pattern+"\\$__", []byte(contracts[types[i]].InputBin))
+			matched, err := regexp.MatchString("__\\$"+pattern+"\\$__", contracts[types[i]].InputBin)
 			if err != nil {
 				log.Error("Could not search for pattern", "pattern", pattern, "contract", contracts[types[i]], "err", err)
 			}

cmd/geth/consolecmd.go

@@ -152,7 +152,7 @@ func remoteConsole(ctx *cli.Context) error {
 func ephemeralConsole(ctx *cli.Context) error {
 	var b strings.Builder
 	for _, file := range ctx.Args().Slice() {
-		b.Write([]byte(fmt.Sprintf("loadScript('%s');", file)))
+		b.WriteString(fmt.Sprintf("loadScript('%s');", file))
 	}
 	utils.Fatalf(`The "js" command is deprecated. Please use the following instead:
 geth --exec "%s" console`, b.String())

core/block_validator.go

@@ -121,7 +121,7 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 // such as amount of used gas, the receipt roots and the state root itself.
 func (v *BlockValidator) ValidateState(block *types.Block, statedb *state.StateDB, res *ProcessResult, stateless bool) error {
 	if res == nil {
-		return fmt.Errorf("nil ProcessResult value")
+		return errors.New("nil ProcessResult value")
 	}
 	header := block.Header()
 	if block.GasUsed() != res.GasUsed {
@@ -150,7 +150,7 @@ func (v *BlockValidator) ValidateState(block *types.Block, statedb *state.StateD
 			return fmt.Errorf("invalid requests hash (remote: %x local: %x)", *header.RequestsHash, reqhash)
 		}
 	} else if res.Requests != nil {
-		return fmt.Errorf("block has requests before prague fork")
+		return errors.New("block has requests before prague fork")
 	}
 	// Validate the state root against the received state root and throw
 	// an error if they don't match.

core/vm/errors.go

@@ -56,7 +56,7 @@ func (e ErrStackUnderflow) Error() string {
 }
 
 func (e ErrStackUnderflow) Unwrap() error {
-	return fmt.Errorf("stack underflow")
+	return errors.New("stack underflow")
 }
 
 // ErrStackOverflow wraps an evm error when the items on the stack exceeds
@@ -71,7 +71,7 @@ func (e ErrStackOverflow) Error() string {
 }
 
 func (e ErrStackOverflow) Unwrap() error {
-	return fmt.Errorf("stack overflow")
+	return errors.New("stack overflow")
 }
 
 // ErrInvalidOpCode wraps an evm error when an invalid opcode is encountered.

internal/flags/flags_test.go

@@ -17,14 +17,12 @@
 package flags
 
 import (
-	"os"
 	"os/user"
 	"runtime"
 	"testing"
 )
 
 func TestPathExpansion(t *testing.T) {
-	t.Parallel()
 
 	user, _ := user.Current()
 	var tests map[string]string
@@ -53,7 +51,7 @@ func TestPathExpansion(t *testing.T) {
 		}
 	}
 
-	os.Setenv(`DDDXXX`, `/tmp`)
+	t.Setenv(`DDDXXX`, `/tmp`)
 	for test, expected := range tests {
 		t.Run(test, func(t *testing.T) {
 			t.Parallel()