com.google.errorprone.bugpatterns.inject.InjectOnMemberAndConstructor Maven / Gradle / Ivy
/*
* Copyright 2018 The Error Prone Authors.
*
* 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.inject;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static com.google.common.collect.Iterables.getOnlyElement;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
import static com.google.errorprone.matchers.InjectMatchers.hasInjectAnnotation;
import static com.google.errorprone.matchers.Matchers.allOf;
import static com.google.errorprone.matchers.Matchers.constructor;
import static com.google.errorprone.matchers.Matchers.isField;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker;
import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.InjectMatchers;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.AnnotationTree;
import com.sun.source.tree.AssignmentTree;
import com.sun.source.tree.ClassTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.VariableTree;
import com.sun.source.util.TreeScanner;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.tree.JCTree;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import javax.lang.model.element.ElementKind;
/**
* Checks if class constructor and members are both annotated as @Inject.
*
* @author [email protected] (Sumit Bhagwani)
*/
@BugPattern(
name = "InjectOnMemberAndConstructor",
summary =
"Members shouldn't be annotated with @Inject if constructor is already annotated @Inject",
severity = ERROR)
public class InjectOnMemberAndConstructor extends BugChecker implements ClassTreeMatcher {
private static final Matcher HAS_CONSTRUCTORS_WITH_INJECT =
constructor(AT_LEAST_ONE, hasInjectAnnotation());
private static final Matcher INSTANCE_FIELD_WITH_INJECT =
allOf(isField(), hasInjectAnnotation());
@Override
public final Description matchClass(ClassTree classTree, VisitorState state) {
if (!HAS_CONSTRUCTORS_WITH_INJECT.matches(classTree, state)) {
return Description.NO_MATCH;
}
List ctors = ASTHelpers.getConstructors(classTree);
List ctorsWithInject =
ctors.stream()
.filter(c -> hasInjectAnnotation().matches(c, state))
.collect(toImmutableList());
if (ctorsWithInject.size() != 1) {
// Injection frameworks don't support multiple @Inject ctors.
// There is already an ERROR check for it.
// http://errorprone.info/bugpattern/MoreThanOneInjectableConstructor
return Description.NO_MATCH;
}
// collect the assignments in ctor
Set variablesAssigned = new HashSet<>();
new TreeScanner() {
@Override
public Void visitAssignment(AssignmentTree tree, Void unused) {
Symbol symbol = ASTHelpers.getSymbol(tree.getVariable());
// check if it is instance field.
if (symbol != null && symbol.getKind() == ElementKind.FIELD && !symbol.isStatic()) {
variablesAssigned.add(symbol);
}
return super.visitAssignment(tree, null);
}
}.scan((JCTree) getOnlyElement(ctorsWithInject), null);
SuggestedFix.Builder fix = SuggestedFix.builder();
VariableTree variableTreeFirstMatch = null;
for (Tree member : classTree.getMembers()) {
if (!(member instanceof VariableTree)) {
continue;
}
VariableTree variableTree = (VariableTree) member;
if (!INSTANCE_FIELD_WITH_INJECT.matches(variableTree, state)) {
continue;
}
if (!variablesAssigned.contains(ASTHelpers.getSymbol(variableTree))) {
continue;
}
variableTreeFirstMatch = variableTree;
removeInjectAnnotationFromVariable(variableTree, state).ifPresent(fix::merge);
}
if (variableTreeFirstMatch == null) {
return Description.NO_MATCH;
}
if (fix.isEmpty()) {
return describeMatch(variableTreeFirstMatch);
}
return describeMatch(variableTreeFirstMatch, fix.build());
}
private static Optional removeInjectAnnotationFromVariable(
VariableTree variableTree, VisitorState state) {
for (AnnotationTree annotation : variableTree.getModifiers().getAnnotations()) {
if (InjectMatchers.IS_APPLICATION_OF_AT_INJECT.matches(annotation, state)) {
return Optional.of(SuggestedFix.replace(annotation, ""));
}
}
return Optional.empty();
}
}