Specify the floating point accuracy of the round() function

src/common/function/FunctionManager.cpp

@@ -55,7 +55,9 @@ std::unordered_map<std::string, std::vector<TypeSignature>> FunctionManager::typ
       TypeSignature({Value::Type::FLOAT}, Value::Type::FLOAT)}},
     {"round",
      {TypeSignature({Value::Type::INT}, Value::Type::FLOAT),
-      TypeSignature({Value::Type::FLOAT}, Value::Type::FLOAT)}},
+      TypeSignature({Value::Type::INT, Value::Type::INT}, Value::Type::FLOAT),
+      TypeSignature({Value::Type::FLOAT}, Value::Type::FLOAT),
+      TypeSignature({Value::Type::FLOAT, Value::Type::INT}, Value::Type::FLOAT)}},
     {"sqrt",
      {TypeSignature({Value::Type::INT}, Value::Type::FLOAT),
       TypeSignature({Value::Type::FLOAT}, Value::Type::FLOAT)}},
@@ -539,17 +541,23 @@ FunctionManager::FunctionManager() {
     // to nearest integral (as a floating-point value)
     auto &attr = functions_["round"];
     attr.minArity_ = 1;
-    attr.maxArity_ = 1;
+    attr.maxArity_ = 2;
     attr.isPure_ = true;
     attr.body_ = [](const auto &args) -> Value {
       switch (args[0].get().type()) {
         case Value::Type::NULLVALUE: {
           return Value::kNullValue;
         }
-        case Value::Type::INT: {
-          return std::round(args[0].get().getInt());
-        }
+        case Value::Type::INT:
         case Value::Type::FLOAT: {
+          if (args.size() == 2) {
+            if (args[1].get().type() == Value::Type::INT) {
+              auto decimal = args[1].get().getInt();
+              return std::round(args[0].get().getFloat() * pow(10, decimal)) / pow(10, decimal);
+            } else {
+              return Value::kNullBadType;
+            }
+          }
           return std::round(args[0].get().getFloat());
         }
         default: {

src/common/function/test/FunctionManagerTest.cpp

@@ -103,6 +103,9 @@ std::unordered_map<std::string, std::vector<Value>> FunctionManagerTest::args_ =
     {"one", {-1.2}},
     {"two", {2, 4}},
     {"pow", {2, 3}},
+    {"round1", {11111.11111, 2}},
+    {"round2", {11111.11111, -1}},
+    {"round3", {11111.11111, -5}},
     {"radians", {180}},
     {"range1", {1, 5}},
     {"range2", {1, 5, 2}},
@@ -268,6 +271,11 @@ TEST_F(FunctionManagerTest, functionCall) {
     TEST_FUNCTION(log, args_["int"], std::log(4));
     TEST_FUNCTION(log2, args_["int"], 2.0);
   }
+  {
+    TEST_FUNCTION(round, args_["round1"], 11111.11);
+    TEST_FUNCTION(round, args_["round2"], 11110.0);
+    TEST_FUNCTION(round, args_["round3"], 0.0);
+  }
   {
     TEST_FUNCTION(range, args_["range1"], Value(List({1, 2, 3, 4, 5})));
     TEST_FUNCTION(range, args_["range2"], Value(List({1, 3, 5})));
@@ -916,11 +924,21 @@ TEST_F(FunctionManagerTest, returnType) {
     ASSERT_TRUE(result.ok());
     EXPECT_EQ(result.value(), Value::Type::FLOAT);
   }
+  {
+    auto result = FunctionManager::getReturnType("round", {Value::Type::INT, Value::Type::INT});
+    ASSERT_TRUE(result.ok());
+    EXPECT_EQ(result.value(), Value::Type::FLOAT);
+  }
   {
     auto result = FunctionManager::getReturnType("round", {Value::Type::FLOAT});
     ASSERT_TRUE(result.ok());
     EXPECT_EQ(result.value(), Value::Type::FLOAT);
   }
+  {
+    auto result = FunctionManager::getReturnType("round", {Value::Type::FLOAT, Value::Type::INT});
+    ASSERT_TRUE(result.ok());
+    EXPECT_EQ(result.value(), Value::Type::FLOAT);
+  }
   {
     auto result = FunctionManager::getReturnType("cbrt", {Value::Type::INT});
     ASSERT_TRUE(result.ok());

tests/tck/features/expression/FunctionCall.feature

@@ -121,6 +121,50 @@ Feature: Function Call Expression
       | result |
       | NULL   |
 
+  Scenario: round
+    When executing query:
+      """
+      YIELD round(3.1415926, 9) as result
+      """
+    Then the result should be, in any order:
+      | result    |
+      | 3.1415926 |
+    When executing query:
+      """
+      YIELD round(3.1415926, 2) as result
+      """
+    Then the result should be, in any order:
+      | result |
+      | 3.14   |
+    When executing query:
+      """
+      YIELD round(3.1415926, 3) as result
+      """
+    Then the result should be, in any order:
+      | result |
+      | 3.142  |
+    When executing query:
+      """
+      YIELD round(3.14159265359, 0) as result
+      """
+    Then the result should be, in any order:
+      | result |
+      | 3.0    |
+    When executing query:
+      """
+      YIELD round(35543.14159265359, -3) as result
+      """
+    Then the result should be, in any order:
+      | result  |
+      | 36000.0 |
+    When executing query:
+      """
+      YIELD round(35543.14159265359, -5) as result
+      """
+    Then the result should be, in any order:
+      | result |
+      | 0.0    |
+
   Scenario: error check
     When executing query:
       """