com.google.errorprone.bugpatterns.TruthConstantAsserts Maven / Gradle / Ivy
/*
* Copyright 2016 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.WARNING;
import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
import static com.google.errorprone.matchers.method.MethodMatchers.staticMethod;
import com.google.errorprone.BugPattern;
import com.google.errorprone.BugPattern.StandardTags;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import java.util.regex.Pattern;
/**
* Points out if Truth Library assert is called on a constant.
*
* @author [email protected] (Sumit Bhagwani)
*/
@BugPattern(
summary = "Truth Library assert is called on a constant.",
severity = WARNING,
tags = StandardTags.FRAGILE_CODE)
public class TruthConstantAsserts extends BugChecker implements MethodInvocationTreeMatcher {
private static final Matcher ASSERT_THAT =
staticMethod().onClass("com.google.common.truth.Truth").named("assertThat");
private static final Pattern EQ_NEQ = Pattern.compile("isEqualTo|isNotEqualTo");
private static final Matcher TRUTH_SUBJECT_CALL =
instanceMethod()
.onDescendantOf("com.google.common.truth.Subject")
.withNameMatching(EQ_NEQ)
.withParameters("java.lang.Object");
@Override
public Description matchMethodInvocation(
MethodInvocationTree methodInvocationTree, VisitorState state) {
if (methodInvocationTree.getArguments().isEmpty()) {
return Description.NO_MATCH;
}
if (!TRUTH_SUBJECT_CALL.matches(methodInvocationTree, state)) {
return Description.NO_MATCH;
}
ExpressionTree rec = ASTHelpers.getReceiver(methodInvocationTree);
if (rec == null) {
return Description.NO_MATCH;
}
if (!ASSERT_THAT.matches(rec, state)) {
return Description.NO_MATCH;
}
ExpressionTree expr = getOnlyElement(((MethodInvocationTree) rec).getArguments());
if (expr == null) {
return Description.NO_MATCH;
}
// check that argument of assertThat is a constant
if (ASTHelpers.constValue(expr) == null) {
return Description.NO_MATCH;
}
// check that expectation isn't a constant
ExpressionTree expectation = getOnlyElement(methodInvocationTree.getArguments());
if (ASTHelpers.constValue(expectation) != null) {
return Description.NO_MATCH;
}
SuggestedFix fix = SuggestedFix.swap(expr, expectation);
return describeMatch(methodInvocationTree, fix);
}
}