feat: find builders in specimen-type

Author: Nylle

src/main/java/com/github/nylle/javafixture/SpecimenType.java

@@ -224,6 +224,16 @@ public List<Method> getFactoryMethods() {
                 .collect(Collectors.toList());
     }
 
+    public List<Builder<T>> findBuilders() {
+        return Stream.of(asClass().getDeclaredMethods())
+                .filter(m -> Modifier.isStatic(m.getModifiers()))
+                .filter(m -> Modifier.isPublic(m.getModifiers()))
+                .filter(m -> !m.getReturnType().equals(asClass()))
+                .map(m -> Builder.create(m, this))
+                .filter(b -> b != null)
+                .collect(toList());
+    }
+
     @Override
     public boolean equals(final Object o) {
         if (this == o) {

src/test/java/com/github/nylle/javafixture/SpecimenTypeTest.java

@@ -2,6 +2,7 @@
 
 import com.github.nylle.javafixture.annotations.testcases.TestCase;
 import com.github.nylle.javafixture.annotations.testcases.TestWithCases;
+import com.github.nylle.javafixture.testobjects.ClassWithBuilder;
 import com.github.nylle.javafixture.testobjects.ITestGeneric;
 import com.github.nylle.javafixture.testobjects.TestAbstractClass;
 import com.github.nylle.javafixture.testobjects.TestEnum;
@@ -58,6 +59,7 @@
 import java.util.concurrent.LinkedTransferQueue;
 import java.util.concurrent.TransferQueue;
 
+import static com.github.nylle.javafixture.CustomizationContext.noContext;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
@@ -368,6 +370,35 @@ void takesAValueMapper() {
         }
     }
 
+    @Nested
+    class FindBuilders {
+
+        @Test
+        void returnsListOfBuilders() {
+            var specimenFactory = new SpecimenFactory(new Context(new Configuration()));
+
+            var sut = new SpecimenType<ClassWithBuilder>(){};
+
+            var actual = sut.findBuilders();
+
+            assertThat(actual).hasSize(1);
+            assertThat(actual.get(0).invoke(specimenFactory, noContext())).isInstanceOf(ClassWithBuilder.class);
+        }
+
+        @TestWithCases
+        @TestCase(class1 = TestObject.class)
+        @TestCase(class1 = ITestGeneric.class)
+        @TestCase(class1 = TestEnum.class)
+        @TestCase(class1 = String.class)
+        void returnsEmptyListIfNoBuildersFound(Class<?> typeWithoutBuilder) {
+            var sut = SpecimenType.fromClass(typeWithoutBuilder);
+
+            var actual = sut.findBuilders();
+
+            assertThat(actual).isEmpty();
+        }
+    }
+
     @Test
     void getComponentType() {
         assertThat(new SpecimenType<int[]>() {}.getComponentType()).isEqualTo(int.class);