add test case for parameterized tests without explicit source

src/test/java/org/pitest/junit5/JUnit5TestUnitFinderTest.java

@@ -20,6 +20,7 @@
 
 import org.junit.jupiter.api.Test;
 import org.pitest.junit5.cucumber.RunCucumberTest;
+import org.pitest.junit5.repository.ParameterizedNoExplicitSource;
 import org.pitest.junit5.repository.TestClassWithFailingTest;
 import org.pitest.junit5.repository.TestClassWithIncludedTestMethod;
 import org.pitest.junit5.repository.TestClassWithInheritedTestMethod;
@@ -100,9 +101,15 @@ void detectsErroringTestsWhenPassingTestsPresent() {
 
     @Test
     void findsAndRunsParameterizedTests() {
-        findsAndRunsNTests(2, TestClassWithParameterizedTestAnnotation.class);
+        findsAndRunsNTests(4, TestClassWithParameterizedTestAnnotation.class);
     }
 
+    @Test
+    void findsAndRunsParameterizedTestsWithoutExplicitMethodSource() {
+        findsAndRunsNTests(2, ParameterizedNoExplicitSource.class);
+    }
+
+
     @Test
     void findsAndRunsTestsWithRepeatedATestAnnotation() {
         findsAndRunsNTests(1, TestClassWithRepeatedTestAnnotation.class);

src/test/java/org/pitest/junit5/repository/ParameterizedNoExplicitSource.java

@@ -0,0 +1,19 @@
+package org.pitest.junit5.repository;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.stream.Stream;
+
+public class ParameterizedNoExplicitSource {
+
+    @ParameterizedTest
+    @MethodSource()
+    public void parameterizedTest(String string) {
+
+    }
+
+    static Stream<String> parameterizedTest() {
+        return Stream.of("foo", "bar");
+    }
+}

src/test/java/org/pitest/junit5/repository/TestClassWithParameterizedTestAnnotation.java

@@ -27,9 +27,9 @@
 public class TestClassWithParameterizedTestAnnotation {
 
     @ParameterizedTest
-    @ValueSource(strings = {"foo"})
+    @ValueSource(strings = {"hello", "goodbye"})
     public void parameterizedTest(String string) {
-        
+
     }
 
     @ParameterizedTest
@@ -39,6 +39,6 @@ public void methodParameterizedTest(String string) {
     }
 
     static Stream<Arguments> someMethod() {
-        return Stream.of(Arguments.of("foo"));
+        return Stream.of(Arguments.of("foo"), Arguments.of("bar"));
     }
 }