/*
 * Copyright 2018 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.CompilationTestHelper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/**
 * Tests for {@link EqualsWrongThing} bugpattern.
 *
 * @author ghm@google.com (Graeme Morgan)
 */
@RunWith(JUnit4.class)
public final class EqualsWrongThingTest {
  private final CompilationTestHelper helper =
      CompilationTestHelper.newInstance(EqualsWrongThing.class, getClass());

  @Test
  public void negative() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import com.google.common.base.Objects;

            class Test {
              private int a;
              private int b;

              @Override
              public boolean equals(Object o) {
                Test that = (Test) o;
                return a == that.a && Objects.equal(b, that.b);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void negativeUnordered() {
    helper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              private int a;
              private int b;

              @Override
              public boolean equals(Object o) {
                Test that = (Test) o;
                return (a == that.a && b == that.b) || (a == that.b && b == that.a);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void negativeMixOfGettersAndFields() {
    helper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              private int a;
              private int b;
              private Object c;

              private int getA() {
                return a;
              }

              private int getB() {
                return b;
              }

              @Override
              public boolean equals(Object o) {
                Test that = (Test) o;
                return this.a == that.getA() && this.b == that.getB() && c.equals(that.c);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive() {
    helper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              private int a;
              private int b;

              @Override
              public boolean equals(Object o) {
                Test that = (Test) o;
                // BUG: Diagnostic contains: comparison between `a` and `b`
                return a == that.b && b == that.b;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positiveGetters() {
    helper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              private int a;
              private int b;

              private int getA() {
                return a;
              }

              private int getB() {
                return b;
              }

              @Override
              public boolean equals(Object o) {
                Test that = (Test) o;
                // BUG: Diagnostic contains: comparison between `getA()` and `getB()`
                return getA() == that.getB() && getB() == that.getB();
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positiveObjects() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import com.google.common.base.Objects;

            class Test {
              private int a;
              private int b;

              @Override
              public boolean equals(Object o) {
                Test that = (Test) o;
                // BUG: Diagnostic contains: comparison between `a` and `b`
                return Objects.equal(a, that.b) && b == that.b;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positiveEquals() {
    helper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              private Object a;
              private Object b;

              @Override
              public boolean equals(Object o) {
                Test that = (Test) o;
                // BUG: Diagnostic contains: comparison between `a` and `b`
                return a.equals(that.b) && b == that.b;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void negativeArraysEquals() {
    helper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Arrays;

            class Test {
              boolean test(int[] a, int[] b) {
                return Arrays.equals(a, 0, 1, b, 2, 3);
              }
            }
            """)
        .doTest();
  }
}
