Added "debug-node-info" flag for inspecting yq AST

pkg/yqlib/printer_node_info_test.go

@@ -0,0 +1,51 @@
+package yqlib
+
+import (
+	"bufio"
+	"bytes"
+	"container/list"
+	"strings"
+	"testing"
+
+	"github.com/mikefarah/yq/v4/test"
+)
+
+func TestNodeInfoPrinter_PrintResults(t *testing.T) {
+	// Create a simple CandidateNode
+	node := &CandidateNode{
+		Kind:        ScalarNode,
+		Style:       DoubleQuotedStyle,
+		Tag:         "!!str",
+		Value:       "hello world",
+		Line:        5,
+		Column:      7,
+		HeadComment: "head",
+		LineComment: "line",
+		FootComment: "foot",
+		Anchor:      "anchor",
+	}
+	listNodes := list.New()
+	listNodes.PushBack(node)
+
+	var output bytes.Buffer
+	writer := bufio.NewWriter(&output)
+	printer := NewNodeInfoPrinter(NewSinglePrinterWriter(writer))
+	err := printer.PrintResults(listNodes)
+	writer.Flush()
+	if err != nil {
+		t.Fatalf("PrintResults error: %v", err)
+	}
+
+	outStr := output.String()
+	// Check for key NodeInfo fields in YAML output using substring checks
+	test.AssertResult(t, true, strings.Contains(outStr, "kind: ScalarNode"))
+	test.AssertResult(t, true, strings.Contains(outStr, "style: DoubleQuotedStyle"))
+	test.AssertResult(t, true, strings.Contains(outStr, "tag: '!!str'"))
+	test.AssertResult(t, true, strings.Contains(outStr, "value: hello world"))
+	test.AssertResult(t, true, strings.Contains(outStr, "line: 5"))
+	test.AssertResult(t, true, strings.Contains(outStr, "column: 7"))
+	test.AssertResult(t, true, strings.Contains(outStr, "headComment: head"))
+	test.AssertResult(t, true, strings.Contains(outStr, "lineComment: line"))
+	test.AssertResult(t, true, strings.Contains(outStr, "footComment: foot"))
+	test.AssertResult(t, true, strings.Contains(outStr, "anchor: anchor"))
+}