/*
* Copyright 2015 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.JDK;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Matchers.constructor;
import static com.google.errorprone.matchers.Matchers.instanceMethod;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.bugpatterns.BugChecker.NewClassTreeMatcher;
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.util.ASTHelpers;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.NewClassTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.Tree.Kind;
import com.sun.tools.javac.tree.JCTree;
/**
* Ban use of YYYY in a SimpleDateFormat pattern, unless it is being used for a week date. Otherwise
* the user almost certainly meant yyyy instead. See the summary in the {@link BugPattern} below for
* more details.
*
* <p>This bug caused a Twitter outage in December 2014.
*/
@BugPattern(
name = "MisusedWeekYear",
summary =
"Use of \"YYYY\" (week year) in a date pattern without \"ww\" (week in year). "
+ "You probably meant to use \"yyyy\" (year) instead.",
category = JDK,
severity = ERROR
)
public class MisusedWeekYear extends BugChecker
implements MethodInvocationTreeMatcher, NewClassTreeMatcher {
private static final String JAVA_SIMPLE_DATE_FORMAT = "java.text.SimpleDateFormat";
private static final String ICU_SIMPLE_DATE_FORMAT = "com.ibm.icu.text.SimpleDateFormat";
private static final Matcher<NewClassTree> simpleDateFormatConstructorMatcher =
Matchers.<NewClassTree>anyOf(
constructor().forClass(JAVA_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String"),
constructor().forClass(JAVA_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String", "java.text.DateFormatSymbols"),
constructor().forClass(JAVA_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String", "java.util.Locale"),
constructor().forClass(ICU_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String"),
constructor().forClass(ICU_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String", "com.ibm.icu.text.DateFormatSymbols"),
constructor().forClass(ICU_SIMPLE_DATE_FORMAT)
.withParameters(
"java.lang.String",
"com.ibm.icu.text.DateFormatSymbols",
"com.ibm.icu.util.ULocale"),
constructor().forClass(ICU_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String", "java.util.Locale"),
constructor().forClass(ICU_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String", "java.lang.String", "com.ibm.icu.util.ULocale"),
constructor().forClass(ICU_SIMPLE_DATE_FORMAT)
.withParameters("java.lang.String", "com.ibm.icu.util.ULocale"));
private static final Matcher<ExpressionTree> applyPatternMatcher =
Matchers.<ExpressionTree>anyOf(
instanceMethod().onExactClass(JAVA_SIMPLE_DATE_FORMAT).named("applyPattern"),
instanceMethod().onExactClass(JAVA_SIMPLE_DATE_FORMAT).named("applyLocalizedPattern"),
instanceMethod().onExactClass(ICU_SIMPLE_DATE_FORMAT).named("applyPattern"),
instanceMethod().onExactClass(ICU_SIMPLE_DATE_FORMAT).named("applyLocalizedPattern"));
/**
* Match uses of SimpleDateFormat.applyPattern and SimpleDateFormat.applyLocalizedPattern in
* which the pattern passed in contains YYYY but not ww, signifying that it was not intended to
* be a week date. If the pattern is a string literal, suggest replacing the YYYY with yyyy.
* If the pattern is a constant, don't give a suggested fix since the fix is nonlocal.
*/
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
if (!applyPatternMatcher.matches(tree, state)) {
return Description.NO_MATCH;
}
return constructDescription(tree, tree.getArguments().get(0));
}
/**
* Match uses of the SimpleDateFormat constructor in which the pattern passed in contains
* YYYY but not ww, signifying that it was not intended to be a week date. If the pattern
* is a string literal, suggest replacing the YYYY with yyyy. If the pattern is a constant, don't
* give a suggested fix since the fix is nonlocal.
*/
@Override
public Description matchNewClass(NewClassTree tree, VisitorState state) {
if (!simpleDateFormatConstructorMatcher.matches(tree, state)) {
return Description.NO_MATCH;
}
return constructDescription(tree, tree.getArguments().get(0));
}
/**
* Given the {@link ExpressionTree} representing the pattern argument to the various
* methods in SimpleDateFormat that accept a pattern, construct the description for this matcher
* to return. May be {@link Description#NO_MATCH} if the pattern does not have a constant value,
* does not use the week year format specifier, or is in proper week date format.
*/
private Description constructDescription(Tree tree, ExpressionTree patternArg) {
String pattern = (String) ASTHelpers.constValue((JCTree) patternArg);
if (pattern != null && pattern.contains("YYYY") && !pattern.contains("ww")) {
if (patternArg.getKind() == Kind.STRING_LITERAL) {
String replacement = patternArg.toString().replace("YYYY", "yyyy");
return describeMatch(tree, SuggestedFix.replace(patternArg, replacement));
} else {
return describeMatch(tree);
}
}
return Description.NO_MATCH;
}
}