#94 - Compile error when field injecting Provider<T>

Author: rbygrave

inject-generator/src/main/java/io/avaje/inject/generator/FieldReader.java

@@ -23,14 +23,18 @@ String getFieldName() {
   String builderGetDependency() {
     StringBuilder sb = new StringBuilder();
     sb.append("b.").append(type.getMethod());
-    sb.append(type.rawType()).append(".class");
+    sb.append(getFieldType()).append(".class");
     if (name != null) {
       sb.append(",\"").append(name).append("\"");
     }
     sb.append(")");
     return sb.toString();
   }
 
+  private String getFieldType() {
+    return Util.unwrapProvider(type.rawType());
+  }
+
   /**
    * Check for request scoped dependency.
    */

inject-test/src/test/java/org/example/coffee/provider/FieldInjectProvider.java

@@ -0,0 +1,16 @@
+package org.example.coffee.provider;
+
+import javax.inject.Inject;
+import javax.inject.Provider;
+import javax.inject.Singleton;
+
+@Singleton
+class FieldInjectProvider {
+
+  @Inject
+  Provider<AProv> aProvProvider;
+
+  AProv testGet() {
+    return aProvProvider.get();
+  }
+}

inject-test/src/test/java/org/example/coffee/provider/FieldInjectProviderTest.java

@@ -0,0 +1,21 @@
+package org.example.coffee.provider;
+
+import io.avaje.inject.SystemContext;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class FieldInjectProviderTest {
+
+  @Test
+  void test() {
+
+    FieldInjectProvider bean = SystemContext.getBean(FieldInjectProvider.class);
+    AProv aProv = bean.testGet();
+
+    assertThat(aProv).isNotNull();
+
+    AProv beanDirect = SystemContext.getBean(AProv.class);
+    assertThat(aProv).isSameAs(beanDirect);
+  }
+}

inject-test/src/test/java/org/example/missing/MFooUser2.java

@@ -0,0 +1,30 @@
+package org.example.missing;
+
+import javax.inject.Singleton;
+
+/**
+ * Has only 1 public constructor so that is chosen for injection.
+ */
+@Singleton
+public class MFooUser2 {
+
+  private final MFoo mf;
+  private final boolean usePublicConstructor;
+
+  public MFooUser2(MFoo mf) {
+    this.mf = mf;
+    this.usePublicConstructor = true;
+  }
+
+  /**
+   * Extra protected constructor usually for unit testing purposes only.
+   */
+  MFooUser2(MFoo mf, boolean dummy) {
+    this.mf = mf;
+    this.usePublicConstructor = true;
+  }
+
+  public boolean isUsePublicConstructor() {
+    return usePublicConstructor;
+  }
+}

inject-test/src/test/java/org/example/missing/SinglePublicConstructorTest.java

@@ -0,0 +1,17 @@
+package org.example.missing;
+
+import io.avaje.inject.SystemContext;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class SinglePublicConstructorTest {
+
+  @Test
+  void beanWithSinglePublicConstructor_expect_publicConstructorChosen() {
+
+    MFooUser2 bean = SystemContext.getBean(MFooUser2.class);
+
+    assertThat(bean.isUsePublicConstructor()).isTrue();
+  }
+}

inject/src/main/java/io/avaje/inject/spi/DBuilder.java

@@ -56,6 +56,11 @@ class DBuilder implements Builder {
    */
   private Class<?> injectTarget;
 
+  /**
+   * Flag set when we are running post construct injection.
+   */
+  private boolean runningPostConstruct;
+
   Builder parent;
 
   /**
@@ -224,6 +229,9 @@ public <T> Provider<T> getProvider(Class<T> cls) {
 
   @Override
   public <T> Provider<T> getProvider(Class<T> cls, String name) {
+    if (runningPostConstruct) {
+      return new ProviderWrapper<>(get(cls, name));
+    }
     ProviderPromise<T> promise = new ProviderPromise<>(cls, name);
     injectors.add(promise);
     return promise;
@@ -256,6 +264,7 @@ private void runInjectors() {
     if (name != null) {
       log.debug("perform field injection in context:{}", name);
     }
+    runningPostConstruct = true;
     for (Consumer<Builder> injector : injectors) {
       injector.accept(this);
     }

inject/src/main/java/io/avaje/inject/spi/ProviderWrapper.java

@@ -0,0 +1,21 @@
+package io.avaje.inject.spi;
+
+import javax.inject.Provider;
+
+/**
+ * Just wrap a bean.
+ */
+class ProviderWrapper<T> implements Provider<T> {
+
+  private T bean;
+
+  ProviderWrapper(T bean) {
+    this.bean = bean;
+  }
+
+  @Override
+  public T get() {
+    return bean;
+  }
+
+}

pom.xml

@@ -26,7 +26,7 @@
   <modules>
     <module>inject</module>
     <module>inject-generator</module>
-<!--    <module>inject-test</module>-->
+    <module>inject-test</module>
   </modules>
 </project>