#29 - Support generic interfaces like Repository<T,I>

This bumps dinject-generator to 1.9 (which does all the work) and adds tests for this

Author: rbygrave

pom.xml

@@ -50,7 +50,7 @@
     <dependency>
       <groupId>io.dinject</groupId>
       <artifactId>dinject-generator</artifactId>
-      <version>1.8</version>
+      <version>1.9</version>
       <scope>test</scope>
     </dependency>
 

src/test/java/org/example/coffee/generic/Haz.java

@@ -0,0 +1,10 @@
+package org.example.coffee.generic;
+
+public class Haz {
+
+  public long id;
+
+  public Haz(Long id) {
+    this.id = id;
+  }
+}

src/test/java/org/example/coffee/generic/HazManager.java

@@ -0,0 +1,22 @@
+package org.example.coffee.generic;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+/**
+ * Has a Dependency via generic interface.
+ */
+@Singleton
+public class HazManager  {
+
+  private final Repository<Haz,Long> hazRepo;
+
+  @Inject
+  public HazManager(Repository<Haz, Long> hazRepo) {
+    this.hazRepo = hazRepo;
+  }
+
+  public Haz find(Long id) {
+    return hazRepo.findById(id);
+  }
+}

src/test/java/org/example/coffee/generic/HazManagerTest.java

@@ -0,0 +1,90 @@
+package org.example.coffee.generic;
+
+import io.dinject.BeanContext;
+import io.dinject.BootContext;
+import io.dinject.SystemContext;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.when;
+
+public class HazManagerTest {
+
+  @Test
+  public void find_when_allWired() {
+
+    HazManager hazManager = SystemContext.getBean(HazManager.class);
+    Haz haz = hazManager.find(42L);
+
+    assertThat(haz.id).isEqualTo(42L);
+  }
+
+  @Test
+  public void fin_with_mockHaz() {
+
+    try (BeanContext context = new BootContext()
+      .withMock(HazRepo.class)
+      .load()) {
+
+      HazManager hazManager = context.getBean(HazManager.class);
+      Haz haz = hazManager.find(42L);
+
+      assertThat(haz).isNull();
+    }
+  }
+
+  @Test
+  public void find_with_stubHazUsingMockito() {
+
+    try (BeanContext context = new BootContext()
+      .withMock(HazRepo.class, hazRepo -> {
+        when(hazRepo.findById(anyLong())).thenReturn(new Haz(-23L));
+      })
+      .load()) {
+
+      HazManager hazManager = context.getBean(HazManager.class);
+      Haz haz = hazManager.find(42L);
+
+      assertThat(haz.id).isEqualTo(-23L);
+    }
+  }
+
+  @Test
+  public void find_with_testDouble() {
+
+    TDHazRepo testDouble = new TDHazRepo();
+
+    try (BeanContext context = new BootContext()
+      .withBeans(testDouble)
+      .load()) {
+
+      HazManager hazManager = context.getBean(HazManager.class);
+
+      Haz haz = hazManager.find(42L);
+      assertThat(haz.id).isEqualTo(64L);
+
+      testDouble.id = 48L;
+      haz = hazManager.find(42L);
+      assertThat(haz.id).isEqualTo(48L);
+
+      testDouble.id = 128L;
+      haz = hazManager.find(42L);
+      assertThat(haz.id).isEqualTo(128L);
+
+    }
+  }
+
+  /**
+   * Test double for HazRepo - nice when we want interesting test behaviour.
+   */
+  class TDHazRepo extends HazRepo {
+
+    long id = 64L;
+
+    @Override
+    public Haz findById(Long paramId) {
+      return new Haz(id);
+    }
+  }
+}

src/test/java/org/example/coffee/generic/HazRepo.java

@@ -0,0 +1,15 @@
+package org.example.coffee.generic;
+
+import javax.inject.Singleton;
+
+/**
+ * Implementation of a generic interface.
+ */
+@Singleton
+public class HazRepo implements Repository<Haz,Long> {
+
+  @Override
+  public Haz findById(Long id) {
+    return new Haz(id);
+  }
+}

src/test/java/org/example/coffee/generic/MultiGenericConsumer.java

@@ -0,0 +1,33 @@
+package org.example.coffee.generic;
+
+import org.example.coffee.grind.AMusher;
+
+import javax.inject.Singleton;
+
+/**
+ * Has multiple dependencies that are generic interface.
+ */
+@Singleton
+class MultiGenericConsumer {
+
+  private final Repository<Haz, Long> hazRepo;
+
+  private final SomeGeneric<String> stringProcessor;
+
+  private final AMusher aMusher;
+
+  MultiGenericConsumer(Repository<Haz, Long> hazRepo, AMusher aMusher, SomeGeneric<String> stringProcessor) {
+    this.hazRepo = hazRepo;
+    this.aMusher = aMusher;
+    this.stringProcessor = stringProcessor;
+  }
+
+  String findAndDo(long id) {
+    final Haz byId = hazRepo.findById(id);
+    return (byId == null) ? "not found" : "found " + stringProcessor.process("" + byId.id);
+  }
+
+  String mushString() {
+    return aMusher.toString();
+  }
+}

src/test/java/org/example/coffee/generic/MultiGenericConsumerTest.java

@@ -0,0 +1,19 @@
+package org.example.coffee.generic;
+
+import io.dinject.SystemContext;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class MultiGenericConsumerTest {
+
+  @Test
+  public void find() {
+
+    MultiGenericConsumer bean = SystemContext.getBean(MultiGenericConsumer.class);
+
+    assertThat(bean.findAndDo(34L)).isEqualTo("found 34 stuff");
+    assertThat(bean.mushString()).isNotNull();
+  }
+
+}

src/test/java/org/example/coffee/generic/Repository.java

@@ -0,0 +1,9 @@
+package org.example.coffee.generic;
+
+/**
+ * Generics interface that we want to use as a dependency.
+ */
+public interface Repository<T,I> {
+
+  T findById(I id);
+}

src/test/java/org/example/coffee/generic/SomeGeneric.java

@@ -0,0 +1,9 @@
+package org.example.coffee.generic;
+
+/**
+ * Generics interface that we want to use as a dependency.
+ */
+public interface SomeGeneric<D> {
+
+  String process(D data);
+}

src/test/java/org/example/coffee/generic/SomeGenericString.java

@@ -0,0 +1,12 @@
+package org.example.coffee.generic;
+
+import javax.inject.Singleton;
+
+@Singleton
+public class SomeGenericString implements SomeGeneric<String> {
+
+  @Override
+  public String process(String data) {
+    return data + " stuff";
+  }
+}