Merge pull request google#273 from cgruber/prohibitsingletononconstru…

…ctor

Prohibit singleton annotations in constructors.

compiler/src/it/singleton-on-constructor/invoker.properties

@@ -0,0 +1 @@
+invoker.buildResult=failure

compiler/src/it/singleton-on-constructor/pom.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Copyright (C) 2013 Google, Inc.
+  Copyright (C) 2013 Square, Inc.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.example.dagger.tests</groupId>
+  <artifactId>singleton-on-constructor</artifactId>
+  <version>HEAD-SNAPSHOT</version>
+  <dependencies>
+    <dependency>
+      <groupId>@dagger.groupId@</groupId>
+      <artifactId>dagger</artifactId>
+      <version>@dagger.version@</version>
+    </dependency>
+    <dependency>
+      <groupId>@dagger.groupId@</groupId>
+      <artifactId>dagger-compiler</artifactId>
+      <version>@dagger.version@</version>
+      <optional>true</optional>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.1</version>
+        <configuration>
+          <source>1.5</source>
+          <target>1.5</target>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

compiler/src/it/singleton-on-constructor/src/main/java/test/TestApp.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2013 Google, Inc.
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package test;
+
+import dagger.Module;
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+class TestApp {
+  @Singleton
+  @Inject 
+  public TestApp() { }
+
+  @Module(injects=TestApp.class)
+  static class TestAppModule { }
+}

compiler/src/it/singleton-on-constructor/verify.bsh

@@ -0,0 +1,7 @@
+import dagger.testing.it.BuildLogValidator;
+import java.io.File;
+
+File buildLog = new File(basedir, "build.log");
+new BuildLogValidator().assertHasText(buildLog, new String[]{
+    "Singleton annotations have no effect on constructors.",
+    "Did you mean to annotate the class? test.TestApp"});

compiler/src/main/java/dagger/internal/codegen/GraphAnalysisInjectBinding.java

@@ -69,6 +69,11 @@ static GraphAnalysisInjectBinding create(TypeElement type, boolean mustHaveInjec
         ExecutableElement constructor = (ExecutableElement) enclosed;
         List<? extends VariableElement> parameters = constructor.getParameters();
         if (hasAtInject(enclosed)) {
+          if (hasAtSingleton(enclosed)) {
+            throw new IllegalArgumentException("Singleton annotations have no effect on "
+                + "constructors. Did you mean to annotate the class? "
+                + type.getQualifiedName().toString());
+          }
           if (hasInjectConstructor) {
             throw new IllegalArgumentException("Too many injectable constructors on "
                 + type.getQualifiedName().toString());
@@ -111,6 +116,10 @@ private static boolean hasAtInject(Element enclosed) {
     return enclosed.getAnnotation(Inject.class) != null;
   }
 
+  private static boolean hasAtSingleton(Element enclosed) {
+    return enclosed.getAnnotation(Singleton.class) != null;
+  }
+
   @Override public void attach(Linker linker) {
     String requiredBy = type.getQualifiedName().toString();
     for (int i = 0; i < keys.size(); i++) {