Implement method randintExcept for RandomGenerator.

Author: aspizu

src/engine/internal/irandomgenerator.h

@@ -12,6 +12,7 @@ class IRandomGenerator
 
         virtual long randint(long start, long end) const = 0;
         virtual double randintDouble(double start, double end) const = 0;
+        virtual long randintExcept(long start, long end, long except) const = 0;
 };
 
 } // namespace libscratchcpp

src/engine/internal/randomgenerator.cpp

@@ -41,3 +41,16 @@ double RandomGenerator::randintDouble(double start, double end) const
     std::uniform_real_distribution<double> distribution(start, end);
     return distribution(*m_generator);
 }
+
+long RandomGenerator::randintExcept(long start, long end, long except) const
+{
+    if (start > end) {
+        std::swap(start, end);
+    }
+    std::uniform_int_distribution<long> distribution(start, end);
+    long value = distribution(*m_generator);
+    if (value == except) {
+        return randintExcept(start, end, except);
+    }
+    return value;
+}

src/engine/internal/randomgenerator.h

@@ -20,6 +20,7 @@ class RandomGenerator : public IRandomGenerator
 
         long randint(long start, long end) const override;
         double randintDouble(double start, double end) const override;
+        long randintExcept(long start, long end, long except) const;
 
     private:
         static std::shared_ptr<RandomGenerator> m_instance;

test/randomgenerator/randomgenerator_test.cpp

@@ -43,3 +43,25 @@ TEST(RandomGeneratorTest, RandIntDouble)
         ASSERT_LE(num, 5.081);
     }
 }
+
+TEST(RandomGeneratorTest, RandInt)
+{
+    auto rng = RandomGenerator::instance();
+    ASSERT_TRUE(rng);
+
+    long num;
+
+    for (int i = 0; i < 25; i++) {
+        num = rng->randintExcept(-2, 3, 0);
+        ASSERT_GE(num, -2);
+        ASSERT_LE(num, 3);
+        ASSERT_NE(num, 0);
+    }
+
+    for (int i = 0; i < 25; i++) {
+        num = rng->randintExcept(5, -3, 2);
+        ASSERT_GE(num, -3);
+        ASSERT_LE(num, 5);
+        ASSERT_NE(num, 2);
+    }
+}