Added line and column operators

pkg/yqlib/operator_line_test.go

@@ -0,0 +1,47 @@
+package yqlib
+
+import (
+	"testing"
+)
+
+var lineOperatorScenarios = []expressionScenario{
+	{
+		description: "Returns line of _value_ node",
+		document:    "a: cat\nb:\n   c: cat",
+		expression:  `.b | line`,
+		expected: []string{
+			"D0, P[b], (!!int)::3\n",
+		},
+	},
+	{
+		description:    "Returns line of _key_ node",
+		subdescription: "Pipe through the key operator to get the line of the key",
+		document:       "a: cat\nb:\n   c: cat",
+		expression:     `.b | key| line`,
+		expected: []string{
+			"D0, P[b], (!!int)::2\n",
+		},
+	},
+	{
+		description: "First line is 1",
+		document:    "a: cat",
+		expression:  `.a | line`,
+		expected: []string{
+			"D0, P[a], (!!int)::1\n",
+		},
+	},
+	{
+		description: "No line data is 0",
+		expression:  `{"a": "new entry"} | line`,
+		expected: []string{
+			"D0, P[], (!!int)::0\n",
+		},
+	},
+}
+
+func TestLineOperatorScenarios(t *testing.T) {
+	for _, tt := range lineOperatorScenarios {
+		testScenario(t, &tt)
+	}
+	documentOperatorScenarios(t, "line", lineOperatorScenarios)
+}