Fix checker for string slices.

Author: antonmedv

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## v1.3.2
+* Fixed checker for string slices.
+
 ## v1.3.1
 * Moved `conf.Options` out of internal package.
 

checker/checker.go

@@ -292,7 +292,9 @@ func (v *visitor) IndexNode(node *ast.IndexNode) reflect.Type {
 func (v *visitor) SliceNode(node *ast.SliceNode) reflect.Type {
 	t := v.visit(node.Node)
 
-	if _, ok := indexType(t); ok {
+	_, isIndex := indexType(t)
+
+	if isIndex || isString(t) {
 		if node.From != nil {
 			from := v.visit(node.From)
 			if !isInteger(from) {

expr_test.go

@@ -780,6 +780,10 @@ func TestExpr(t *testing.T) {
 			`Variadic("empty")`,
 			[]int{},
 		},
+		{
+			`String[:3]`,
+			"str",
+		},
 	}
 
 	for _, tt := range tests {