Make json_array functions return null with malformed json (#10630)

Summary:
Pull Request resolved: #10630

This is match the behavior of the equivalent Presto functions, which return NULL when they are given malformed json.

Reviewed By: kevinwilfong

Differential Revision: D60557066

fbshipit-source-id: 980cf1f73394c99fc2ee4bf24d3e005b90cd5351

velox/functions/prestosql/JsonFunctions.h

@@ -71,6 +71,9 @@ struct JsonArrayContainsFunction {
     if (simdjsonParse(paddedJson).get(jsonDoc)) {
       return false;
     }
+    if (jsonDoc.type().error()) {
+      return false;
+    }
 
     if (jsonDoc.type() != simdjson::ondemand::json_type::array) {
       return false;
@@ -132,6 +135,9 @@ struct JsonArrayLengthFunction {
     if (simdjsonParse(paddedJson).get(jsonDoc)) {
       return false;
     }
+    if (jsonDoc.type().error()) {
+      return false;
+    }
 
     if (jsonDoc.type() != simdjson::ondemand::json_type::array) {
       return false;
@@ -159,6 +165,9 @@ struct JsonArrayGetFunction {
     if (simdjsonParse(paddedJson).get(jsonDoc)) {
       return false;
     }
+    if (jsonDoc.type().error()) {
+      return false;
+    }
 
     if (jsonDoc.type() != simdjson::ondemand::json_type::array) {
       return false;

velox/functions/prestosql/tests/JsonFunctionsTest.cpp

@@ -356,6 +356,9 @@ TEST_F(JsonFunctionsTest, jsonArrayLength) {
   EXPECT_EQ(jsonArrayLength(R"({"k1":"v1"})"), std::nullopt);
   EXPECT_EQ(jsonArrayLength(R"({"k1":[0,1,2]})"), std::nullopt);
   EXPECT_EQ(jsonArrayLength(R"({"k1":[0,1,2], "k2":"v1"})"), std::nullopt);
+
+  // Malformed Json.
+  EXPECT_EQ(jsonArrayLength(R"((})"), std::nullopt);
 }
 
 TEST_F(JsonFunctionsTest, jsonArrayGet) {
@@ -372,6 +375,9 @@ TEST_F(JsonFunctionsTest, jsonArrayGet) {
   EXPECT_FALSE(arrayGet("{}", 1).has_value());
   EXPECT_FALSE(arrayGet("[]", 1).has_value());
 
+  // Malformed json.
+  EXPECT_FALSE(arrayGet("([1]})", 0).has_value());
+
   EXPECT_EQ(arrayGet("[1, 2, 3]", 0), "1");
   EXPECT_EQ(arrayGet("[1, 2, 3]", 1), "2");
   EXPECT_EQ(arrayGet("[1, 2, 3]", 2), "3");
@@ -589,6 +595,14 @@ TEST_F(JsonFunctionsTest, jsonArrayContainsString) {
       true);
 }
 
+TEST_F(JsonFunctionsTest, jsonArrayContainsMalformed) {
+  auto [jsonVector, _] = makeVectors(R"([]})");
+  EXPECT_EQ(
+      evaluateOnce<bool>(
+          "json_array_contains(c0, 'a')", makeRowVector({jsonVector})),
+      std::nullopt);
+}
+
 TEST_F(JsonFunctionsTest, jsonSize) {
   EXPECT_EQ(jsonSize(R"({"k1":{"k2": 999}, "k3": 1})", "$.k1.k2"), 0);
   EXPECT_EQ(jsonSize(R"({"k1":{"k2": 999}, "k3": 1})", "$.k1"), 1);