org.openrewrite.staticanalysis.CaseInsensitiveComparisonsDoNotChangeCase Maven / Gradle / Ivy

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/*
 * Copyright 2021 the original author or 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
 * 

 * https://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 org.openrewrite.staticanalysis;

import org.jspecify.annotations.Nullable;
import org.openrewrite.ExecutionContext;
import org.openrewrite.Preconditions;
import org.openrewrite.Recipe;
import org.openrewrite.TreeVisitor;
import org.openrewrite.internal.ListUtils;
import org.openrewrite.java.JavaIsoVisitor;
import org.openrewrite.java.MethodMatcher;
import org.openrewrite.java.search.UsesMethod;
import org.openrewrite.java.tree.J;

import java.time.Duration;
import java.util.Collections;
import java.util.Set;

public class CaseInsensitiveComparisonsDoNotChangeCase extends Recipe {
    @Override
    public String getDisplayName() {
        return "CaseInsensitive comparisons do not alter case";
    }

    @Override
    public String getDescription() {
        return "Remove `String#toLowerCase()` or `String#toUpperCase()` from `String#equalsIgnoreCase(..)` comparisons.";
    }

    @Override
    public Set getTags() {
        return Collections.singleton("RSPEC-S1157");
    }

    @Override
    public Duration getEstimatedEffortPerOccurrence() {
        return Duration.ofMinutes(5);
    }

    @Override
    public TreeVisitor getVisitor() {
        return Preconditions.check(new UsesMethod<>("java.lang.String equalsIgnoreCase(java.lang.String)"), new CaseInsensitiveComparisonVisitor<>());
    }

    private static class CaseInsensitiveComparisonVisitor extends JavaIsoVisitor {
        private static final MethodMatcher COMPARE_IGNORE_CASE_METHOD_MATCHER = new MethodMatcher("java.lang.String equalsIgnoreCase(java.lang.String)");
        private static final MethodMatcher TO_LOWER_CASE_METHOD_MATCHER = new MethodMatcher("java.lang.String toLowerCase()");
        private static final MethodMatcher TO_UPPER_CASE_METHOD_MATCHER = new MethodMatcher("java.lang.String toUpperCase()");

        @Override
        public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, ExecutionContext executionContext) {
            J.MethodInvocation mi = super.visitMethodInvocation(method, executionContext);
            if (COMPARE_IGNORE_CASE_METHOD_MATCHER.matches(mi)) {
                mi = mi.withArguments(ListUtils.map(mi.getArguments(), arg -> {
                    if (arg instanceof J.MethodInvocation && isChangeCaseMethod(arg)) {
                        return ((J.MethodInvocation) arg).getSelect();
                    }
                    return arg;
                }));
                if (isChangeCaseMethod(mi.getSelect())) {
                    J.MethodInvocation mChangeCase = (J.MethodInvocation) mi.getSelect();
                    mi = mi.withSelect(mChangeCase.getSelect());
                }
            }
            return mi;
        }

        private boolean isChangeCaseMethod(@Nullable J j) {
            if (j instanceof J.MethodInvocation) {
                J.MethodInvocation mi = (J.MethodInvocation) j;
                return TO_LOWER_CASE_METHOD_MATCHER.matches(mi) || TO_UPPER_CASE_METHOD_MATCHER.matches(mi);
            }
            return false;
        }
    }
}