fix: use pre-defined specimen when available

Refs: #98

Author: akutschera

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

@@ -8,6 +8,7 @@
 import com.github.nylle.javafixture.specimen.InterfaceSpecimen;
 import com.github.nylle.javafixture.specimen.MapSpecimen;
 import com.github.nylle.javafixture.specimen.ObjectSpecimen;
+import com.github.nylle.javafixture.specimen.PredefinedSpecimen;
 import com.github.nylle.javafixture.specimen.PrimitiveSpecimen;
 import com.github.nylle.javafixture.specimen.SpecialSpecimen;
 import com.github.nylle.javafixture.specimen.TimeSpecimen;
@@ -22,6 +23,10 @@ public SpecimenFactory(Context context) {
 
     public <T> ISpecimen<T> build(final SpecimenType<T> type) {
 
+        if ( context.isCached(type) ) {
+            return new PredefinedSpecimen<>( type, context );
+        }
+
         if (type.isPrimitive() || type.isBoxed() || type.asClass() == String.class) {
             return new PrimitiveSpecimen<>(type, context);
         }

src/main/java/com/github/nylle/javafixture/specimen/PredefinedSpecimen.java

@@ -0,0 +1,32 @@
+package com.github.nylle.javafixture.specimen;
+
+import com.github.nylle.javafixture.Context;
+import com.github.nylle.javafixture.CustomizationContext;
+import com.github.nylle.javafixture.ISpecimen;
+import com.github.nylle.javafixture.SpecimenType;
+
+import java.lang.annotation.Annotation;
+
+public class PredefinedSpecimen<T> implements ISpecimen<T> {
+
+    private final Context context;
+    private final SpecimenType<T> type;
+
+    public PredefinedSpecimen( SpecimenType<T> type, Context context ) {
+        if (type == null) {
+            throw new IllegalArgumentException("type: null");
+        }
+
+        if (context == null) {
+            throw new IllegalArgumentException("context: null");
+        }
+
+        this.context = context;
+        this.type = type;
+    }
+
+    @Override
+    public T create( CustomizationContext customizationContext, Annotation[] annotations ) {
+        return context.cached( type );
+    }
+}

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

@@ -19,6 +19,7 @@
 import com.github.nylle.javafixture.testobjects.example.ContractPosition;
 import com.github.nylle.javafixture.testobjects.withconstructor.TestObjectWithGenericConstructor;
 import com.github.nylle.javafixture.testobjects.withconstructor.TestObjectWithoutDefaultConstructor;
+import org.assertj.core.api.SoftAssertions;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
@@ -242,13 +243,18 @@ void canOmitPrivatePrimitiveFieldAndInitializesDefaultValue() {
         @Test
         void objectCanBeCustomizedWithType() {
             var expected = Period.ofDays(42);
+            var expectedFile = new File( "expected-file-name" );
             var result = fixture().build(Contract.class)
                     .with(Period.class, expected)
+                    .with(File.class, expectedFile)
                     .create();
 
             var actual = result.getBaseContractPosition().getRemainingPeriod();
 
-            assertThat(actual).isSameAs(expected);
+            var softly = new SoftAssertions();
+            softly.assertThat(actual).isSameAs(expected);
+            softly.assertThat(result.getBaseContractPosition().getFile()).isEqualTo( expectedFile );
+            softly.assertAll();
         }
 
         @Test

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

@@ -9,12 +9,15 @@
 import com.github.nylle.javafixture.specimen.InterfaceSpecimen;
 import com.github.nylle.javafixture.specimen.MapSpecimen;
 import com.github.nylle.javafixture.specimen.ObjectSpecimen;
+import com.github.nylle.javafixture.specimen.PredefinedSpecimen;
 import com.github.nylle.javafixture.specimen.PrimitiveSpecimen;
 import com.github.nylle.javafixture.specimen.SpecialSpecimen;
 import com.github.nylle.javafixture.specimen.TimeSpecimen;
 import com.github.nylle.javafixture.testobjects.TestEnum;
 import com.github.nylle.javafixture.testobjects.TestObjectGeneric;
+import com.github.nylle.javafixture.testobjects.TestPrimitive;
 import com.github.nylle.javafixture.testobjects.example.IContract;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 import java.io.File;
@@ -66,7 +69,18 @@ void buildGeneric() {
         assertThat(sut.build(new SpecimenType<Map<String, Integer>>(){})).isExactlyInstanceOf(MapSpecimen.class);
         assertThat(sut.build(new SpecimenType<Class<String>>(){})).isExactlyInstanceOf(GenericSpecimen.class);
         assertThat(sut.build(new SpecimenType<TestObjectGeneric<String, List<Integer>>>(){})).isExactlyInstanceOf(GenericSpecimen.class);
+    }
+
+    @Test
+    @DisplayName( "when cache contains a predefined value, return this" )
+    void buildReturnsCacnedValue() {
+        var context = new Context( new Configuration() );
+        var cachedValue = new TestPrimitive();
+        var type = SpecimenType.fromClass( TestPrimitive.class );
+        context.overwrite( type, cachedValue );
+        var sut = new SpecimenFactory( context );
 
+        assertThat( sut.build( type ) ).isExactlyInstanceOf( PredefinedSpecimen.class );
     }
 
 

src/test/java/com/github/nylle/javafixture/specimen/PredefinedSpecimenTest.java

@@ -0,0 +1,47 @@
+package com.github.nylle.javafixture.specimen;
+
+import com.github.nylle.javafixture.Context;
+import com.github.nylle.javafixture.SpecimenType;
+import com.github.nylle.javafixture.testobjects.TestEnum;
+import com.github.nylle.javafixture.testobjects.TestObject;
+import org.junit.jupiter.api.Test;
+
+import static com.github.nylle.javafixture.Configuration.configure;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class PredefinedSpecimenTest {
+    @Test
+    void typeIsRequired() {
+        assertThatThrownBy(() -> new PredefinedSpecimen<>(null, new Context( configure())))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("type: null");
+    }
+
+    @Test
+    void contextIsRequired() {
+        assertThatThrownBy(() -> new PredefinedSpecimen<>( SpecimenType.fromClass( TestEnum.class), null))
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("context: null");
+    }
+
+    @Test
+    void createReturnsCachedValue() {
+        var type = SpecimenType.fromClass( TestObject.class );
+        var testObject = new TestObject( null, null, null );
+        var context = new Context( configure() );
+        context.overwrite( type,  testObject);
+        var sut = new PredefinedSpecimen<>( type, context );
+
+        assertThat( sut.create( null, null ) ).isEqualTo( testObject );
+    }
+
+    @Test
+    void createReturnsNullIfNoCachedValueIsFound() {
+        var type = SpecimenType.fromClass( TestObject.class );
+        var context = new Context( configure() );
+        var sut = new PredefinedSpecimen<>( type, context );
+
+        assertThat( sut.create( null, null ) ).isNull();
+    }
+}