eth/tracers/js: fix isPush for push0 (ethereum#28520)

Fixes so that `push0` opcode is correctly reported as `true` by the `IsPush` function

---------

Co-authored-by: Martin Holst Swende <martin@swende.se>

core/asm/asm_test.go

@@ -22,53 +22,37 @@ import (
 	"encoding/hex"
 )
 
-// Tests disassembling the instructions for valid evm code
-func TestInstructionIteratorValid(t *testing.T) {
-	cnt := 0
-	script, _ := hex.DecodeString("61000000")
-
-	it := NewInstructionIterator(script)
-	for it.Next() {
-		cnt++
-	}
-
-	if err := it.Error(); err != nil {
-		t.Errorf("Expected 2, but encountered error %v instead.", err)
-	}
-	if cnt != 2 {
-		t.Errorf("Expected 2, but got %v instead.", cnt)
-	}
-}
-
-// Tests disassembling the instructions for invalid evm code
-func TestInstructionIteratorInvalid(t *testing.T) {
-	cnt := 0
-	script, _ := hex.DecodeString("6100")
-
-	it := NewInstructionIterator(script)
-	for it.Next() {
-		cnt++
-	}
-
-	if it.Error() == nil {
-		t.Errorf("Expected an error, but got %v instead.", cnt)
-	}
-}
-
-// Tests disassembling the instructions for empty evm code
-func TestInstructionIteratorEmpty(t *testing.T) {
-	cnt := 0
-	script, _ := hex.DecodeString("")
-
-	it := NewInstructionIterator(script)
-	for it.Next() {
-		cnt++
-	}
-
-	if err := it.Error(); err != nil {
-		t.Errorf("Expected 0, but encountered error %v instead.", err)
-	}
-	if cnt != 0 {
-		t.Errorf("Expected 0, but got %v instead.", cnt)
+// Tests disassembling instructions
+func TestInstructionIterator(t *testing.T) {
+	for i, tc := range []struct {
+		want    int
+		code    string
+		wantErr string
+	}{
+		{2, "61000000", ""},                             // valid code
+		{0, "6100", "incomplete push instruction at 0"}, // invalid code
+		{2, "5900", ""},                                 // push0
+		{0, "", ""},                                     // empty
+
+	} {
+		var (
+			have    int
+			code, _ = hex.DecodeString(tc.code)
+			it      = NewInstructionIterator(code)
+		)
+		for it.Next() {
+			have++
+		}
+		var haveErr = ""
+		if it.Error() != nil {
+			haveErr = it.Error().Error()
+		}
+		if haveErr != tc.wantErr {
+			t.Errorf("test %d: encountered error: %q want %q", i, haveErr, tc.wantErr)
+			continue
+		}
+		if have != tc.want {
+			t.Errorf("wrong instruction count, have %d want %d", have, tc.want)
+		}
 	}
 }

core/vm/opcodes.go

@@ -25,11 +25,7 @@ type OpCode byte
 
 // IsPush specifies if an opcode is a PUSH opcode.
 func (op OpCode) IsPush() bool {
-	switch op {
-	case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32:
-		return true
-	}
-	return false
+	return PUSH0 <= op && op <= PUSH32
 }
 
 // 0x0 range - arithmetic ops.