com.google.errorprone.bugpatterns.IterablePathParameter Maven / Gradle / Ivy
/*
* Copyright 2017 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;
import static com.google.common.collect.Iterables.getOnlyElement;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.util.ASTHelpers.isSameType;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.VariableTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ParameterizedTypeTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.VariableTree;
import com.sun.tools.javac.code.Symbol.VarSymbol;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Type.WildcardType;
import com.sun.tools.javac.code.TypeTag;
import com.sun.tools.javac.tree.JCTree.JCLambda;
import com.sun.tools.javac.tree.JCTree.JCLambda.ParameterKind;
import java.nio.file.Path;
import javax.lang.model.element.ElementKind;
/** A {@link BugChecker}; see the associated {@link BugPattern} annotation for details. */
@BugPattern(
name = "IterablePathParameter",
summary = "Path implements Iterable; prefer Collection for clarity",
severity = ERROR)
public class IterablePathParameter extends BugChecker implements VariableTreeMatcher {
@Override
public Description matchVariable(VariableTree tree, VisitorState state) {
Type type = ASTHelpers.getType(tree);
VarSymbol symbol = ASTHelpers.getSymbol(tree);
if (type == null || symbol == null) {
return NO_MATCH;
}
if (symbol.getKind() != ElementKind.PARAMETER) {
return NO_MATCH;
}
if (!isSameType(type, state.getSymtab().iterableType, state)) {
return NO_MATCH;
}
if (type.getTypeArguments().isEmpty()) {
return NO_MATCH;
}
if (!isSameType(
wildBound(getOnlyElement(type.getTypeArguments())),
state.getTypeFromString(Path.class.getName()),
state)) {
return NO_MATCH;
}
Description.Builder description = buildDescription(tree);
Tree parent = state.getPath().getParentPath().getLeaf();
if (tree.getType() instanceof ParameterizedTypeTree
&& (!(parent instanceof JCLambda)
|| ((JCLambda) parent).paramKind == ParameterKind.EXPLICIT)) {
description.addFix(
SuggestedFix.builder()
.addImport("java.util.Collection")
.replace(((ParameterizedTypeTree) tree.getType()).getType(), "Collection")
.build());
}
return description.build();
}
static Type wildBound(Type type) {
return type.hasTag(TypeTag.WILDCARD) ? ((WildcardType) type).type : type;
}
}