BAEL 6249: Gray Box Testing (#13610)

* test implementation and sut class

* finishing up unit tests

* format

* fix test name

* changing method source name

* creating new module testing-techniques

* fix package name

---------

Co-authored-by: Ashley Frieze <ashley@incredible.org.uk>

testing-modules/testing-techniques/src/test/java/com/baeldung/greyboxtesting/SalaryCommissionPercentageCalculatorUnitTest.java

@@ -0,0 +1,41 @@
+package com.baeldung.greyboxtesting;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.math.BigDecimal;
+import java.util.stream.Stream;
+
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.Level.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.SalesImpact.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.Seniority.*;
+import static com.baeldung.greyboxtesting.SalaryCommissionPercentageCalculator.Type.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class SalaryCommissionPercentageCalculatorUnitTest {
+
+    private SalaryCommissionPercentageCalculator testTarget = new SalaryCommissionPercentageCalculator();
+
+    @ParameterizedTest
+    @MethodSource("provideReferenceTestScenarioTable")
+    void givenReferenceTable_whenCalculateAverageCommission_thenReturnExpectedResult(Level level, Type type, Seniority seniority, SalesImpact impact, double expected) {
+        BigDecimal got = testTarget.calculate(level, type, seniority, impact);
+        assertEquals(BigDecimal.valueOf(expected), got);
+    }
+
+    private static Stream<Arguments> provideReferenceTestScenarioTable() {
+        return Stream.of(
+                Arguments.of(L1, FULL_TIME_COMMISSIONED, JR, LOW, 0.26),
+                Arguments.of(L1, CONTRACTOR, SR, MEDIUM, 0.12),
+                Arguments.of(L1, FREELANCER, MID, HIGH, 0.11),
+                Arguments.of(L2, FULL_TIME_COMMISSIONED, SR, HIGH, 0.18),
+                Arguments.of(L2, CONTRACTOR, MID, LOW, 0.11),
+                Arguments.of(L2, FREELANCER, JR, MEDIUM, 0.24),
+                Arguments.of(L3, FULL_TIME_COMMISSIONED, MID, MEDIUM, 0.17),
+                Arguments.of(L3, CONTRACTOR, JR, HIGH, 0.28),
+                Arguments.of(L3, FREELANCER, SR, LOW, 0.12)
+        );
+    }
+}