fix false positive with indexical expressions (#16)

Co-authored-by: wangchunlu <wangchunlu@bilibili.com>

Author: sylvia7788

durationcheck.go

@@ -98,6 +98,8 @@ func isUnacceptableExpr(pass *analysis.Pass, expr ast.Expr) bool {
 		return !isAcceptableNestedExpr(pass, e)
 	case *ast.ParenExpr:
 		return !isAcceptableNestedExpr(pass, e)
+	case *ast.IndexExpr:
+		return !isAcceptableNestedExpr(pass, e)
 	default:
 		return true
 	}
@@ -156,6 +158,9 @@ func isAcceptableNestedExpr(pass *analysis.Pass, n ast.Expr) bool {
 		return isAcceptableNestedExpr(pass, e.X)
 	case *ast.ParenExpr:
 		return isAcceptableNestedExpr(pass, e.X)
+	case *ast.IndexExpr:
+		t := pass.TypesInfo.TypeOf(e)
+		return !isDuration(t)
 	default:
 		return false
 	}

testdata/src/a/a.go

@@ -19,6 +19,7 @@ type myStruct struct {
 func validCases() {
 	y := 10
 	ms := myStruct{fieldA: 10, fieldB: 10 * time.Second, fieldC: func(v int) *int { return &v }(10)}
+	intArr := []int{1}
 
 	_ = time.Second * 30
 
@@ -71,11 +72,14 @@ func validCases() {
 	_ = b.SomeInt * time.Second
 
 	_ = time.Second * b.SomeInt
+
+	_ = time.Duration(intArr[0]) * time.Second
 }
 
 func invalidCases() {
 	x := 30 * time.Second
 	ms := myStruct{fieldA: 10, fieldB: 10 * time.Second}
+	tdArr := []time.Duration{1}
 
 	_ = x * time.Second // want `Multiplication of durations`
 
@@ -106,6 +110,8 @@ func invalidCases() {
 	_ = b.SomeDuration * time.Second // want `Multiplication of durations`
 
 	_ = time.Second * b.SomeDuration // want `Multiplication of durations`
+
+	_ = time.Duration(tdArr[0]) * time.Second // want `Multiplication of durations`
 }
 
 func someDuration() time.Duration {