[C++] test message length functions

Author: Egor Seredin

sbe-samples/src/main/cpp/GeneratedStubExample.cpp

@@ -314,8 +314,9 @@ int main(int argc, const char* argv[])
 
     std::size_t encodeHdrLength = encodeHdr(hdr, car, buffer, 0, sizeof(buffer));
     std::size_t encodeMsgLength = encodeCar(car, buffer, hdr.encodedLength(), sizeof(buffer));
+    std::size_t predictedLength = Car::computeLength({11, 14, 13}, {3, 3}, 5, 9, 8);
 
-    cout << "Encoded Lengths are " << encodeHdrLength << " + " << encodeMsgLength << endl;
+    cout << "Encoded Lengths are " << encodeHdrLength << " + " << encodeMsgLength << " (" << predictedLength << ")" << endl;
 
     std::size_t decodeHdrLength = decodeHdr(hdr, buffer, 0, sizeof(buffer));
     std::size_t decodeMsgLength = decodeCar(car, buffer, hdr.encodedLength(), hdr.blockLength(), hdr.version(), sizeof(buffer));

sbe-tool/src/test/cpp/CodeGenTest.cpp

@@ -426,6 +426,25 @@ TEST_F(CodeGenTest, shouldBeAbleToEncodeCarCorrectly)
     offset += COLOR_LENGTH;
 
     EXPECT_EQ(sz, offset);
+
+    std::uint64_t predictedCarSz = Car::computeLength(
+        {
+            FUEL_FIGURES_1_USAGE_DESCRIPTION_LENGTH,
+            FUEL_FIGURES_2_USAGE_DESCRIPTION_LENGTH,
+            FUEL_FIGURES_3_USAGE_DESCRIPTION_LENGTH
+        },
+        {
+            ACCELERATION_COUNT,
+            ACCELERATION_COUNT
+        },
+        MANUFACTURER_LENGTH,
+        MODEL_LENGTH,
+        ACTIVATION_CODE_LENGTH,
+        COLOR_LENGTH
+    );
+    EXPECT_EQ(sz, predictedCarSz);
+    EXPECT_EQ(Car::isConstLength(), false);
+    EXPECT_EQ(Car::PerformanceFigures::Acceleration::isConstLength(), true);
 }
 
 TEST_F(CodeGenTest, shouldBeAbleToEncodeHeaderPlusCarCorrectly)
@@ -467,6 +486,8 @@ TEST_F(CodeGenTest, shouldbeAbleToEncodeAndDecodeHeaderPlusCarCorrectly)
 
     m_carDecoder.wrapForDecode(buffer, m_hdrDecoder.encodedLength(), Car::sbeBlockLength(), Car::sbeSchemaVersion(), hdrSz + carSz);
 
+    EXPECT_EQ(m_carDecoder.decodeLength(), expectedCarSize);
+
     EXPECT_EQ(m_carDecoder.serialNumber(), SERIAL_NUMBER);
     EXPECT_EQ(m_carDecoder.modelYear(), MODEL_YEAR);
     EXPECT_EQ(m_carDecoder.available(), AVAILABLE);
@@ -578,6 +599,7 @@ TEST_F(CodeGenTest, shouldbeAbleToEncodeAndDecodeHeaderPlusCarCorrectly)
     EXPECT_EQ(std::string(m_carDecoder.color(), COLOR_LENGTH), COLOR);
 
     EXPECT_EQ(m_carDecoder.encodedLength(), expectedCarSize);
+    EXPECT_EQ(m_carDecoder.decodeLength(), expectedCarSize);
 }
 
 struct CallbacksForEach

sbe-tool/src/test/cpp/CompositeElementsTest.cpp

@@ -210,6 +210,8 @@ TEST_F(CompositeElementsTest, shouldEncodeMsgCorrectly)
     std::uint64_t offset = 0;
 
     ASSERT_EQ(sz, 8u + 22u);
+    ASSERT_EQ(Msg::isConstLength(), true);
+    EXPECT_EQ(sz, Msg::sbeBlockAndHeaderLength());
 
     EXPECT_EQ(*((std::uint16_t *)(bufferPtr + offset)), Msg::sbeBlockLength());
     offset += sizeof(std::uint16_t);