From e9bbaf3f20ec8f303e977b8e6752152b11cd75b9 Mon Sep 17 00:00:00 2001
From: "loki-gh-app[bot]" <160051081+loki-gh-app[bot]@users.noreply.github.com>
Date: Wed, 16 Oct 2024 19:31:46 +0300
Subject: [PATCH] fix(logql): updated JSONExpressionParser not to unescape
 extracted values if it is JSON object. (backport release-3.2.x) (#14502)

Co-authored-by: Vladyslav Diachenko <82767850+vlad-diachenko@users.noreply.github.com>
---
 pkg/logql/log/parser.go      |  2 ++
 pkg/logql/log/parser_test.go | 30 ++++++++++++++++++++++++++----
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/pkg/logql/log/parser.go b/pkg/logql/log/parser.go
index 9a5ae1395069c..4893999016878 100644
--- a/pkg/logql/log/parser.go
+++ b/pkg/logql/log/parser.go
@@ -617,6 +617,8 @@ func (j *JSONExpressionParser) Process(_ int64, line []byte, lbs *LabelsBuilder)
 		switch typ {
 		case jsonparser.Null:
 			lbs.Set(ParsedLabel, key, "")
+		case jsonparser.Object:
+			lbs.Set(ParsedLabel, key, string(data))
 		default:
 			lbs.Set(ParsedLabel, key, unescapeJSONString(data))
 		}
diff --git a/pkg/logql/log/parser_test.go b/pkg/logql/log/parser_test.go
index 654e35bb13e73..d78bafbc86883 100644
--- a/pkg/logql/log/parser_test.go
+++ b/pkg/logql/log/parser_test.go
@@ -522,13 +522,35 @@ func TestJSONExpressionParser(t *testing.T) {
 			),
 			NoParserHints(),
 		},
+		{
+			"nested object with escaped value",
+			[]byte(`{"app":{"name":"great \"loki\""}`),
+			[]LabelExtractionExpr{
+				NewLabelExtractionExpr("app", `app`),
+			},
+			labels.FromStrings("foo", "bar"),
+			labels.FromStrings("foo", "bar",
+				"app", `{"name":"great \"loki\""}`,
+			),
+			NoParserHints(),
+		},
+		{
+			"field with escaped value inside the json string",
+			[]byte(`{"app":"{\"name\":\"great \\\"loki\\\"\"}"}`),
+			[]LabelExtractionExpr{
+				NewLabelExtractionExpr("app", `app`),
+			},
+			labels.FromStrings("foo", "bar"),
+			labels.FromStrings("foo", "bar",
+				"app", `{"name":"great \"loki\""}`,
+			),
+			NoParserHints(),
+		},
 	}
 	for _, tt := range tests {
-		j, err := NewJSONExpressionParser(tt.expressions)
-		if err != nil {
-			t.Fatalf("cannot create JSON expression parser: %s", err.Error())
-		}
 		t.Run(tt.name, func(t *testing.T) {
+			j, err := NewJSONExpressionParser(tt.expressions)
+			require.NoError(t, err, "cannot create JSON expression parser")
 			b := NewBaseLabelsBuilderWithGrouping(nil, tt.hints, false, false).ForLabels(tt.lbs, tt.lbs.Hash())
 			b.Reset()
 			_, _ = j.Process(0, tt.line, b)