Minor fixes

pkg/yqlib/doc/Delete Operator.md

@@ -48,3 +48,19 @@ a: cat
 b: dog
 ```
 
+### Delete matching entries
+Given a sample.yml file of:
+```yaml
+a: cat
+b: dog
+c: bat
+```
+then
+```bash
+yq eval 'del( .[] | select(. == "*at") )' sample.yml
+```
+will output
+```yaml
+b: dog
+```
+

pkg/yqlib/encoder_test.go

@@ -37,7 +37,10 @@ func TestJsonEncoderPreservesObjectOrder(t *testing.T) {
 		panic(err)
 	}
 	node := inputs.Front().Value.(*CandidateNode).Node
-	jsonEncoder.Encode(node)
+	err = jsonEncoder.Encode(node)
+	if err != nil {
+		panic(err)
+	}
 	writer.Flush()
 	test.AssertResult(t, expectedJson, output.String())
 

pkg/yqlib/lib.go

@@ -68,10 +68,7 @@ var Empty = &OperationType{Type: "EMPTY", NumArgs: 50, Handler: EmptyOperator}
 
 var RecursiveDescent = &OperationType{Type: "RECURSIVE_DESCENT", NumArgs: 0, Precedence: 50, Handler: RecursiveDescentOperator}
 
-// not sure yet
-
 var Select = &OperationType{Type: "SELECT", NumArgs: 1, Precedence: 50, Handler: SelectOperator}
-
 var DeleteChild = &OperationType{Type: "DELETE", NumArgs: 1, Precedence: 40, Handler: DeleteChildOperator}
 
 // var Exists = &OperationType{Type: "Length", NumArgs: 2, Precedence: 35}

pkg/yqlib/operator_delete_test.go

@@ -29,6 +29,14 @@ var deleteOperatorScenarios = []expressionScenario{
 			"D0, P[], (doc)::{a: cat, b: dog}\n",
 		},
 	},
+	{
+		description: "Delete matching entries",
+		document:    `{a: cat, b: dog, c: bat}`,
+		expression:  `del( .[] | select(. == "*at") )`,
+		expected: []string{
+			"D0, P[], (doc)::{b: dog}\n",
+		},
+	},
 }
 
 func TestDeleteOperatorScenarios(t *testing.T) {

pkg/yqlib/printer_test.go

@@ -35,9 +35,20 @@ func TestPrinterMultipleDocsInSequence(t *testing.T) {
 	el = el.Next()
 	sample3 := nodeToMap(el.Value.(*CandidateNode))
 
-	printer.PrintResults(sample1)
-	printer.PrintResults(sample2)
-	printer.PrintResults(sample3)
+	err = printer.PrintResults(sample1)
+	if err != nil {
+		panic(err)
+	}
+
+	err = printer.PrintResults(sample2)
+	if err != nil {
+		panic(err)
+	}
+
+	err = printer.PrintResults(sample3)
+	if err != nil {
+		panic(err)
+	}
 
 	writer.Flush()
 	test.AssertResult(t, multiDocSample, output.String())
@@ -54,7 +65,10 @@ func TestPrinterMultipleDocsInSinglePrint(t *testing.T) {
 		panic(err)
 	}
 
-	printer.PrintResults(inputs)
+	err = printer.PrintResults(inputs)
+	if err != nil {
+		panic(err)
+	}
 
 	writer.Flush()
 	test.AssertResult(t, multiDocSample, output.String())
@@ -70,7 +84,10 @@ func TestPrinterMultipleDocsJson(t *testing.T) {
 		panic(err)
 	}
 
-	printer.PrintResults(inputs)
+	err = printer.PrintResults(inputs)
+	if err != nil {
+		panic(err)
+	}
 
 	expected := `{"a":"banana"}
 {"a":"apple"}