/*
 * Copyright 2019 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 com.google.errorprone.BugCheckerRefactoringTestHelper;
import com.google.errorprone.CompilationTestHelper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests for {@link CompareToZero} bugpattern. */
@RunWith(JUnit4.class)
public final class CompareToZeroTest {
  private final CompilationTestHelper compilationHelper =
      CompilationTestHelper.newInstance(CompareToZero.class, getClass());
  private final BugCheckerRefactoringTestHelper refactoringHelper =
      BugCheckerRefactoringTestHelper.newInstance(CompareToZero.class, getClass());

  @Test
  public void positive() {
    compilationHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              boolean test(Integer i) {
                // BUG: Diagnostic contains: compared
                return i.compareTo(2) == -1;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positiveStaticCompare() {
    compilationHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              boolean test(boolean x, boolean y) {
                // BUG: Diagnostic contains: compared
                return Boolean.compare(x, y) == -1;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positiveSuggestionForConsistency() {
    compilationHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              boolean test(Integer i) {
                // BUG: Diagnostic contains: consistency
                return i.compareTo(2) <= -1;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_gte1_has_1_finding() {
    compilationHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              boolean test(Integer i) {
                // BUG: Diagnostic matches: KEY
                return i.compareTo(2) >= 1;
              }
            }
            """)
        .expectErrorMessage(
            "KEY", msg -> msg.contains("consistency") && !msg.contains("implementation"))
        .doTest();
  }

  @Test
  public void positiveAddition() {
    compilationHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              int test(Integer i) {
                // BUG: Diagnostic contains:
                return i.compareTo(2) + i.compareTo(3);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void stringConcat_ignored() {
    compilationHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              String test(Integer i) {
                return "" + i.compareTo(3);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void refactoring() {
    refactoringHelper
        .addInputLines(
            "Test.java",
            """
            class Test {
              void test(Integer i) {
                boolean b1 = i.compareTo(2) == -1;
                boolean b2 = i.compareTo(2) > -1;
                boolean b3 = -1 < i.compareTo(2);
                boolean b4 = i.compareTo(2) < 1;
                boolean b5 = i.compareTo(2) != -1;
                boolean b6 = i.compareTo(2) != 1;
                boolean b7 = i.compareTo(2) <= -1;
                boolean b8 = ((i.compareTo(2))) >= 1;
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            class Test {
              void test(Integer i) {
                boolean b1 = i.compareTo(2) < 0;
                boolean b2 = i.compareTo(2) >= 0;
                boolean b3 = i.compareTo(2) >= 0;
                boolean b4 = i.compareTo(2) <= 0;
                boolean b5 = i.compareTo(2) >= 0;
                boolean b6 = i.compareTo(2) <= 0;
                boolean b7 = i.compareTo(2) < 0;
                boolean b8 = ((i.compareTo(2))) > 0;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void negative() {
    compilationHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              void test(Integer i) {
                boolean b1 = i.compareTo(2) < 0;
                boolean b2 = i.compareTo(2) > 0;
                boolean b3 = i.compareTo(2) == 0;
              }
            }
            """)
        .doTest();
  }
}
