adding tests

evaluable.go

@@ -138,27 +138,25 @@ func variable(path Evaluables) Evaluable {
 						vvElem = vvElem.Elem()
 					}
 
-					v = vvElem.Interface()
+					if vvElem.IsValid() {
+						v = vvElem.Interface()
 
-					continue
+						continue
+					}
 				}
 
 				if vvElem.Kind() == reflect.Slice {
-					i, err := strconv.Atoi(k)
+					if i, err := strconv.Atoi(k); err == nil && i >= 0 && vv.Len() > i {
+						vvElem = vv.Index(i)
 
-					if err != nil {
-						continue
-					}
+						if vvElem.Kind() == reflect.Ptr {
+							vvElem = vvElem.Elem()
+						}
 
-					vvElem = vv.Index(i)
+						v = vvElem.Interface()
 
-					if vvElem.Kind() == reflect.Ptr {
-						vvElem = vvElem.Elem()
+						continue
 					}
-
-					v = vvElem.Interface()
-
-					continue
 				}
 
 				if vvElem.Kind() != reflect.Struct {

gval_evaluationFailure_test.go

@@ -340,6 +340,18 @@ func TestModifierTyping(test *testing.T) {
 			},
 			wantErr: unknownParameter,
 		},
+		{
+			name:       "Nested slice call index out of bound",
+			expression: `foo.Nested.Slice[10]`,
+			parameter:  map[string]interface{}{"foo": foo},
+			wantErr:    unknownParameter,
+		},
+		{
+			name:       "Nested map call missing key",
+			expression: `foo.Nested.Map["d"]`,
+			parameter:  map[string]interface{}{"foo": foo},
+			wantErr:    unknownParameter,
+		},
 		{
 			name:       "invalid selector",
 			expression: "hello[world()]",

gval_parameterized_test.go

@@ -448,6 +448,18 @@ func TestParameterized(t *testing.T) {
 				parameter:  map[string]interface{}{"foo": foo},
 				want:       "funkalicious",
 			},
+			{
+				name:       "Nested map call",
+				expression: `foo.Nested.Map["a"]`,
+				parameter:  map[string]interface{}{"foo": foo},
+				want:       1,
+			},
+			{
+				name:       "Nested slice call",
+				expression: `foo.Nested.Slice[1]`,
+				parameter:  map[string]interface{}{"foo": foo},
+				want:       2,
+			},
 			{
 
 				name:       "Parameter call with + modifier",

gval_test.go

@@ -75,7 +75,9 @@ func (d dummyParameter) AlwaysFail() (interface{}, error) {
 }
 
 type dummyNestedParameter struct {
-	Funk string
+	Funk  string
+	Map   map[string]int
+	Slice []int
 }
 
 func (d dummyNestedParameter) Dunk(arg1 string) string {
@@ -88,7 +90,9 @@ var foo = dummyParameter{
 	BoolFalse: false,
 	Nil:       nil,
 	Nested: dummyNestedParameter{
-		Funk: "funkalicious",
+		Funk:  "funkalicious",
+		Map:   map[string]int{"a": 1, "b": 2, "c": 3},
+		Slice: []int{1, 2, 3},
 	},
 }