From 08fc058934c48bf57b55063fe59af726d382b6d3 Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Sat, 30 Oct 2021 13:37:21 +1100
Subject: [PATCH] Fix JSON encoding removing null #985

---
 pkg/yqlib/encoder.go      |  3 ++-
 pkg/yqlib/encoder_test.go | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/pkg/yqlib/encoder.go b/pkg/yqlib/encoder.go
index a77b57cb..2e92e3aa 100644
--- a/pkg/yqlib/encoder.go
+++ b/pkg/yqlib/encoder.go
@@ -211,7 +211,8 @@ func (o *orderedMap) UnmarshalYAML(node *yaml.Node) error {
 		}
 		return nil
 	case yaml.SequenceNode:
-		var res []orderedMap
+		// note that this has to be a pointer, so that nulls can be represented.
+		var res []*orderedMap
 		if err := node.Decode(&res); err != nil {
 			return err
 		}
diff --git a/pkg/yqlib/encoder_test.go b/pkg/yqlib/encoder_test.go
index 333749d9..283e89ee 100644
--- a/pkg/yqlib/encoder_test.go
+++ b/pkg/yqlib/encoder_test.go
@@ -48,6 +48,24 @@ banana:
 	test.AssertResult(t, expectedJson, actualJson)
 }
 
+func TestJsonNullInArray(t *testing.T) {
+	var sampleYaml = `[null]`
+	var actualJson = yamlToJson(sampleYaml, 0)
+	test.AssertResult(t, sampleYaml, actualJson)
+}
+
+func TestJsonNull(t *testing.T) {
+	var sampleYaml = `null`
+	var actualJson = yamlToJson(sampleYaml, 0)
+	test.AssertResult(t, sampleYaml, actualJson)
+}
+
+func TestJsonNullInObject(t *testing.T) {
+	var sampleYaml = `{x: null}`
+	var actualJson = yamlToJson(sampleYaml, 0)
+	test.AssertResult(t, `{"x":null}`, actualJson)
+}
+
 func TestJsonEncoderDoesNotEscapeHTMLChars(t *testing.T) {
 	var sampleYaml = `build: "( ./lint && ./format && ./compile ) < src.code"`
 	var expectedJson = `{"build":"( ./lint && ./format && ./compile ) < src.code"}`