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

/**
 * Unit tests for {@link UnsafeReflectiveConstructionCast} bug pattern.
 *
 * @author bhagwani@google.com (Sumit Bhagwani)
 */
@RunWith(JUnit4.class)
public class UnsafeReflectiveConstructionCastTest {
  private final BugCheckerRefactoringTestHelper testHelper =
      BugCheckerRefactoringTestHelper.newInstance(
          UnsafeReflectiveConstructionCast.class, getClass());
  private final CompilationTestHelper compilationHelper =
      CompilationTestHelper.newInstance(UnsafeReflectiveConstructionCast.class, getClass());

  @Test
  public void testPositiveCase() {
    testHelper
        .addInputLines(
            "in/Test.java",
            "class Test {",
            "  private String newInstanceOnGetDeclaredConstructorChained() throws Exception {",
            "    return (String) ",
            "      Class.forName(\"java.lang.String\").getDeclaredConstructor().newInstance();",
            "  }",
            "}")
        .addOutputLines(
            "out/Test.java",
            "class Test {",
            "  private String newInstanceOnGetDeclaredConstructorChained() throws Exception {",
            "    return ",
            "     "
                + " Class.forName(\"java.lang.String\").asSubclass(String.class).getDeclaredConstructor().newInstance();",
            "  }",
            "}")
        .doTest();
  }

  @Test
  public void testPositiveCaseWithErasure() {
    testHelper
        .addInputLines(
            "in/Test.java",
            "class Test {",
            "  class Fn<T> {};",
            "  private Fn<String> newInstanceOnGetDeclaredConstructorChained() throws Exception {",
            "    return (Fn<String>) Class.forName(\"Fn\").getDeclaredConstructor().newInstance();",
            "  }",
            "}")
        .addOutputLines(
            "out/Test.java",
            "class Test {",
            "  class Fn<T> {};",
            "  private Fn<String> newInstanceOnGetDeclaredConstructorChained() throws Exception {",
            "    return (Fn<String>)"
                + " Class.forName(\"Fn\").asSubclass(Fn.class).getDeclaredConstructor().newInstance();",
            "  }",
            "}")
        .doTest();
  }

  @Test
  public void testNegativeCaseWithIntersection() {
    compilationHelper
        .addSourceLines(
            "in/Test.java",
            "import java.io.Serializable;",
            "class Test {",
            "  interface Fn {};",
            "  private Fn newInstanceOnGetDeclaredConstructorChained() throws Exception {",
            "    return (Serializable & Fn) ",
            "      Class.forName(\"Fn\").getDeclaredConstructor().newInstance();",
            "  }",
            "}")
        .doTest();
  }

  @Test
  public void testNegativeCase() {
    compilationHelper.addSourceFile("UnsafeReflectiveConstructionCastNegativeCases.java").doTest();
  }
}
