Fixes update-assign with collect object issue #830

pkg/yqlib/operator_collect_object.go

@@ -17,9 +17,12 @@ import (
 ...
 */
 
-func collectObjectOperator(d *dataTreeNavigator, context Context, expressionNode *ExpressionNode) (Context, error) {
+func collectObjectOperator(d *dataTreeNavigator, originalContext Context, expressionNode *ExpressionNode) (Context, error) {
 	log.Debugf("-- collectObjectOperation")
 
+	context := originalContext.Clone()
+	context.DontAutoCreate = false
+
 	if context.MatchingNodes.Len() == 0 {
 		node := &yaml.Node{Kind: yaml.MappingNode, Tag: "!!map", Value: "{}"}
 		candidate := &CandidateNode{Node: node}

pkg/yqlib/operator_collect_object_test.go

@@ -5,6 +5,30 @@ import (
 )
 
 var collectObjectOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:    true,
+		document:   "a: []",
+		expression: `.a += [{"key": "att2", "value": "val2"}]`,
+		expected: []string{
+			"D0, P[], (doc)::a: [{key: att2, value: val2}]\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "",
+		expression: `.a += {"key": "att2", "value": "val2"}`,
+		expected: []string{
+			"D0, P[], ()::a:\n    key: att2\n    value: val2\n",
+		},
+	},
+	{
+		skipDoc:    true,
+		document:   "",
+		expression: `.a += [0]`,
+		expected: []string{
+			"D0, P[], ()::a:\n    - 0\n",
+		},
+	},
 	{
 		description: `Collect empty object`,
 		document:    ``,

pkg/yqlib/operator_collect_test.go

@@ -5,6 +5,14 @@ import (
 )
 
 var collectOperatorScenarios = []expressionScenario{
+	{
+		skipDoc:    true,
+		document:   ``,
+		expression: `.a += [0]`,
+		expected: []string{
+			"D0, P[], ()::a:\n    - 0\n",
+		},
+	},
 	{
 		description: "Collect empty",
 		document:    ``,