fix(#1966): go2Gno loses type info

gnovm/pkg/gnolang/preprocess.go

@@ -882,17 +882,26 @@ func Preprocess(store Store, ctx BlockNode, n Node) Node {
 					// Left not const, Right not const ------------------
 					if n.Op == EQL || n.Op == NEQ {
 						// If == or !=, no conversions.
-					} else if lnt, ok := lt.(*NativeType); ok {
+					} else if ok, lnt := func() (bool, *NativeType) {
+						lnt, okl := lt.(*NativeType)
+						_, okr := rt.(*NativeType)
+						return okl && okr, lnt
+					}(); ok {
 						if debug {
 							if !isShift {
 								assertSameTypes(lt, rt)
 							}
 						}
-						// If left and right are native type,
+						// If left and right are native type, and same type
 						// convert left and right to gno, then
 						// convert result back to native.
 						//
 						// get concrete native base type.
+						if lt.TypeID() != rt.TypeID() {
+							panic(fmt.Sprintf(
+								"incompatible types in binary expression: %v %v %v",
+								n.Left, n.Op, n.Right))
+						}
 						pt := go2GnoBaseType(lnt.Type).(PrimitiveType)
 						// convert n.Left to (gno) pt type,
 						ln := Expr(Call(pt.String(), n.Left))

gnovm/pkg/gnolang/preprocess_test.go

@@ -0,0 +1,66 @@
+package gnolang
+
+import (
+	"bytes"
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPrepocessBinaryExpressionPrimaryAndNative(t *testing.T) {
+	t.Parallel()
+
+	out := new(bytes.Buffer)
+	pkg := NewPackageNode("time", "time", nil)
+	pkg.DefineGoNativeValue("Millisecond", time.Millisecond)
+	pkg.DefineGoNativeValue("Second", time.Second)
+	pkg.DefineGoNativeType(reflect.TypeOf(time.Duration(0)))
+	pv := pkg.NewPackage()
+	store := gonativeTestStore(pkg, pv)
+
+	m := NewMachineWithOptions(MachineOptions{
+		PkgPath: "main",
+		Output:  out,
+		Store:   store,
+	})
+
+	c := `package main
+	import "time"
+func main() {
+	var a int64 = 2
+	println(a * time.Second)
+	
+}`
+	n := MustParseFile("main.go", c)
+	assert.Panics(t, func() { m.RunFiles(n) }, "should panic: invalid operation: int64 * time.Duration")
+}
+
+func TestPrepocessBinaryExpressionNativeAndNative(t *testing.T) {
+	t.Parallel()
+
+	out := new(bytes.Buffer)
+	pkg := NewPackageNode("time", "time", nil)
+	pkg.DefineGoNativeValue("March", time.March)
+	pkg.DefineGoNativeValue("Wednesday", time.Wednesday)
+	pkg.DefineGoNativeType(reflect.TypeOf(time.Month(0)))
+	pkg.DefineGoNativeType(reflect.TypeOf(time.Weekday(0)))
+	pv := pkg.NewPackage()
+	store := gonativeTestStore(pkg, pv)
+
+	m := NewMachineWithOptions(MachineOptions{
+		PkgPath: "main",
+		Output:  out,
+		Store:   store,
+	})
+
+	c := `package main
+	import "time"
+func main() {
+	println(time.March * time.Wednesday)
+	
+}`
+	n := MustParseFile("main.go", c)
+	assert.Panics(t, func() { m.RunFiles(n) }, "should panic: invalid operation: time.Month * time.Weekday")
+}