/*
* Copyright 2013 Google Inc. All Rights Reserved.
*
* 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 com.google.errorprone.bugpatterns;
import static com.google.errorprone.BugPattern.Category.GUICE;
import static com.google.errorprone.BugPattern.MaturityLevel.MATURE;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Matchers.allOf;
import static com.google.errorprone.matchers.Matchers.annotations;
import static com.google.errorprone.matchers.Matchers.constructor;
import static com.google.errorprone.matchers.Matchers.hasAnnotation;
import static com.google.errorprone.matchers.Matchers.methodHasParameters;
import static com.google.errorprone.matchers.MultiMatcher.MatchType.ANY;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.matchers.Matchers;
import com.google.errorprone.matchers.MultiMatcher;
import com.sun.source.tree.AnnotationTree;
import com.sun.source.tree.ClassTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.VariableTree;
/**
* This checker matches iff *both* of the following conditions are true:
* 1) The class is assisted:
* a) If there is a constructor that is annotated with @Inject and that constructor has at least
* one parameter that is annotated with @Assisted.
* b) If there is no @Inject constructor and at least one constructor is annotated with
* @AssistedInject.
* 2) There is an annotation on the class, and the annotation is itself annotated with
* @ScopeAnnotation.
*
* @author eaftan@google.com (Eddie Aftandilian)
*/
@BugPattern(name = "GuiceAssistedInjectScoping",
summary = "Scope annotation on implementation class of AssistedInject factory is not allowed",
explanation =
"Classes that AssistedInject factories create may not be annotated with scope " +
"annotations, such as @Singleton. This will cause a Guice error at runtime.\n\n" +
"See [https://code.google.com/p/google-guice/issues/detail?id=742 this bug report] for " +
"details.",
category = GUICE, severity = ERROR, maturity = MATURE)
public class GuiceAssistedInjectScoping extends BugChecker implements ClassTreeMatcher {
private static final String GUICE_SCOPE_ANNOTATION = "com.google.inject.ScopeAnnotation";
private static final String JAVAX_SCOPE_ANNOTATION = "javax.inject.Scope";
private static final String ASSISTED_ANNOTATION = "com.google.inject.assistedinject.Assisted";
private static final String GUICE_INJECT_ANNOTATION = "com.google.inject.Inject";
private static final String JAVAX_INJECT_ANNOTATION = "javax.inject.Inject";
private static final String ASSISTED_INJECT_ANNOTATION =
"com.google.inject.assistedinject.AssistedInject";
/**
* Matches classes that have an annotation that itself is annotated with @ScopeAnnotation.
*/
private static MultiMatcher<ClassTree, AnnotationTree> classAnnotationMatcher =
annotations(ANY, Matchers.<AnnotationTree>anyOf(hasAnnotation(GUICE_SCOPE_ANNOTATION),
hasAnnotation(JAVAX_SCOPE_ANNOTATION)));
/**
* Matches if any constructor of a class is annotated with an @Inject annotation.
*/
private static MultiMatcher<ClassTree, MethodTree> constructorWithInjectMatcher =
constructor(ANY, Matchers.<MethodTree>anyOf(hasAnnotation(GUICE_INJECT_ANNOTATION),
hasAnnotation(JAVAX_INJECT_ANNOTATION)));
/**
* Matches if:
* 1) If there is a constructor that is annotated with @Inject and that constructor has at least
* one parameter that is annotated with @Assisted.
* 2) If there is no @Inject constructor and at least one constructor is annotated with
* @AssistedInject.
*/
private static Matcher<ClassTree> assistedMatcher = new Matcher<ClassTree>() {
@Override
public boolean matches(ClassTree classTree, VisitorState state) {
if (constructorWithInjectMatcher.matches(classTree, state)) {
// Check constructor with @Inject annotation for parameter with @Assisted annotation.
return methodHasParameters(ANY,
Matchers.<VariableTree>hasAnnotation(ASSISTED_ANNOTATION))
.matches(constructorWithInjectMatcher.getMatchingNode(), state);
}
return constructor(ANY, Matchers.<MethodTree>hasAnnotation(ASSISTED_INJECT_ANNOTATION))
.matches(classTree, state);
}
};
public static final Matcher<ClassTree> MATCHER = allOf(classAnnotationMatcher, assistedMatcher);
@Override
public final Description matchClass(ClassTree classTree, VisitorState state) {
if (!MATCHER.matches(classTree, state)) {
return Description.NO_MATCH;
}
AnnotationTree annotationWithScopeAnnotation = classAnnotationMatcher.getMatchingNode();
if (annotationWithScopeAnnotation == null) {
throw new IllegalStateException("Expected to find an annotation that was annotated " +
"with @ScopeAnnotation");
}
return describeMatch(annotationWithScopeAnnotation,
SuggestedFix.delete(annotationWithScopeAnnotation));
}
}