From c887042a1b8d976979340d92f6435c29a6b41e44 Mon Sep 17 00:00:00 2001
From: Mike Farah <mikefarah@gmail.com>
Date: Sun, 30 Oct 2022 16:29:42 +1100
Subject: [PATCH] Fixing null csv bug #1404

---
 examples/sample_objects.csv |  2 +-
 pkg/yqlib/csv_test.go       | 11 +++++-
 pkg/yqlib/lib.go            |  6 +++
 pkg/yqlib/lib_test.go       | 73 ++++++++++++++++++++++++++++++++++++-
 pkg/yqlib/operators_test.go |  2 +-
 5 files changed, 90 insertions(+), 4 deletions(-)

diff --git a/examples/sample_objects.csv b/examples/sample_objects.csv
index 7059b75d..84ae60b8 100644
--- a/examples/sample_objects.csv
+++ b/examples/sample_objects.csv
@@ -1,3 +1,3 @@
 name,numberOfCats,likesApples,height
-Gary,1,true,168.8
+,1,true,168.8
 Samantha's Rabbit,2,false,-188.8
\ No newline at end of file
diff --git a/pkg/yqlib/csv_test.go b/pkg/yqlib/csv_test.go
index 4ab3306d..58f76c83 100644
--- a/pkg/yqlib/csv_test.go
+++ b/pkg/yqlib/csv_test.go
@@ -12,7 +12,9 @@ const csvSimple = `name,numberOfCats,likesApples,height
 Gary,1,true,168.8
 Samantha's Rabbit,2,false,-188.8
 `
-
+const csvMissing = `name,numberOfCats,likesApples,height
+,null,,168.8
+`
 const expectedUpdatedSimpleCsv = `name,numberOfCats,likesApples,height
 Gary,3,true,168.8
 Samantha's Rabbit,2,false,-188.8
@@ -110,6 +112,13 @@ var csvScenarios = []formatScenario{
 		expected:       csvSimpleMissingData,
 		scenarioType:   "encode-csv",
 	},
+	{
+		description:  "decode csv missing",
+		skipDoc:      true,
+		input:        csvMissing,
+		expected:     csvMissing,
+		scenarioType: "roundtrip-csv",
+	},
 	{
 		description:    "Parse CSV into an array of objects",
 		subdescription: "First row is assumed to be the header row.",
diff --git a/pkg/yqlib/lib.go b/pkg/yqlib/lib.go
index 76e52b03..d678c4ce 100644
--- a/pkg/yqlib/lib.go
+++ b/pkg/yqlib/lib.go
@@ -249,6 +249,12 @@ func guessTagFromCustomType(node *yaml.Node) string {
 }
 
 func parseSnippet(value string) (*yaml.Node, error) {
+	if value == "" {
+		return &yaml.Node{
+			Kind: yaml.ScalarNode,
+			Tag:  "!!null",
+		}, nil
+	}
 	decoder := NewYamlDecoder(ConfiguredYamlPreferences)
 	err := decoder.Init(strings.NewReader(value))
 	if err != nil {
diff --git a/pkg/yqlib/lib_test.go b/pkg/yqlib/lib_test.go
index 810a0611..663afede 100644
--- a/pkg/yqlib/lib_test.go
+++ b/pkg/yqlib/lib_test.go
@@ -1,6 +1,11 @@
 package yqlib
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+	yaml "gopkg.in/yaml.v3"
+)
 
 func TestGetLogger(t *testing.T) {
 	l := GetLogger()
@@ -8,3 +13,69 @@ func TestGetLogger(t *testing.T) {
 		t.Fatal("GetLogger should return the yq logger instance, not a copy")
 	}
 }
+
+type parseSnippetScenario struct {
+	snippet  string
+	expected *yaml.Node
+}
+
+var parseSnippetScenarios = []parseSnippetScenario{
+	{
+		snippet: "",
+		expected: &yaml.Node{
+			Kind: yaml.ScalarNode,
+			Tag:  "!!null",
+		},
+	},
+	{
+		snippet: "3",
+		expected: &yaml.Node{
+			Kind:   yaml.ScalarNode,
+			Tag:    "!!int",
+			Value:  "3",
+			Line:   1,
+			Column: 1,
+		},
+	},
+	{
+		snippet: "cat",
+		expected: &yaml.Node{
+			Kind:   yaml.ScalarNode,
+			Tag:    "!!str",
+			Value:  "cat",
+			Line:   1,
+			Column: 1,
+		},
+	},
+	{
+		snippet: "3.1",
+		expected: &yaml.Node{
+			Kind:   yaml.ScalarNode,
+			Tag:    "!!float",
+			Value:  "3.1",
+			Line:   1,
+			Column: 1,
+		},
+	},
+	{
+		snippet: "true",
+		expected: &yaml.Node{
+			Kind:   yaml.ScalarNode,
+			Tag:    "!!bool",
+			Value:  "true",
+			Line:   1,
+			Column: 1,
+		},
+	},
+}
+
+func TestParseSnippet(t *testing.T) {
+	for _, tt := range parseSnippetScenarios {
+		actual, err := parseSnippet(tt.snippet)
+		if err != nil {
+			t.Error(tt.snippet)
+			t.Error(err)
+		}
+		test.AssertResultComplexWithContext(t, tt.expected, actual, tt.snippet)
+	}
+}
diff --git a/pkg/yqlib/operators_test.go b/pkg/yqlib/operators_test.go
index f3363dc6..79757895 100644
--- a/pkg/yqlib/operators_test.go
+++ b/pkg/yqlib/operators_test.go
@@ -31,7 +31,7 @@ type expressionScenario struct {
 }
 
 func TestMain(m *testing.M) {
-	logging.SetLevel(logging.DEBUG, "")
+	logging.SetLevel(logging.ERROR, "")
 	Now = func() time.Time {
 		return time.Date(2021, time.May, 19, 1, 2, 3, 4, time.UTC)
 	}