code: ///////////////////////////////////////////////////////////////////////////
  //                   __                _      _   ________               //
  //                  / /   ____  ____ _(_)____/ | / / ____/               //
  //                 / /   / __ \/ __ `/ / ___/  |/ / / __                 //
  //                / /___/ /_/ / /_/ / / /__/ /|  / /_/ /                 //
  //               /_____/\____/\__, /_/\___/_/ |_/\____/                  //
  //                           /____/                                      //
  //                                                                       //
  //               The Next Generation Logic Library                       //
  //                                                                       //
  ///////////////////////////////////////////////////////////////////////////
  //                                                                       //
  //  Copyright 2015-20xx Christoph Zengler                                //
  //                                                                       //
  //  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 org.logicng.propositions;
  
  import static org.assertj.core.api.Assertions.assertThat;
  
  import org.junit.jupiter.api.Test;
  import org.logicng.formulas.FormulaFactory;
  import org.logicng.io.parsers.ParserException;
  import org.logicng.io.parsers.PropositionalParser;
  
  /**
   * Unit tests for {@link StandardProposition}.
   * @version 2.0.0
   * @since 1.0
   */
  public class StandardPropositionTest {
  
      private final PropositionalParser p;
      private final StandardProposition prop1;
      private final StandardProposition prop2;
  
      public StandardPropositionTest() throws ParserException {
          final FormulaFactory f = new FormulaFactory();
          this.p = new PropositionalParser(f);
          this.prop1 = new StandardProposition(this.p.parse("a & b"));
          this.prop2 = new StandardProposition("prop2", this.p.parse("a & b & ~c"));
      }
  
      @Test
      public void testGetters() throws ParserException {
          assertThat(this.prop1.formula()).isEqualTo(this.p.parse("a & b"));
          assertThat(this.prop2.formula()).isEqualTo(this.p.parse("a & b & ~c"));
  
          assertThat(this.prop1.description()).isEqualTo("");
          assertThat(this.prop2.description()).isEqualTo("prop2");
      }
  
      @Test
      public void testHashCode() throws ParserException {
          final StandardProposition prop11 = new StandardProposition(this.p.parse("a & b"));
          final StandardProposition prop21 = new StandardProposition("prop2", this.p.parse("a & b & ~c"));
          assertThat(this.prop1.hashCode()).isEqualTo(this.prop1.hashCode());
          assertThat(prop11.hashCode()).isEqualTo(this.prop1.hashCode());
          assertThat(prop21.hashCode()).isEqualTo(this.prop2.hashCode());
      }
  
      @Test
      public void testEquals() throws ParserException {
          final StandardProposition prop11 = new StandardProposition(this.p.parse("a & b"));
          final StandardProposition prop21 = new StandardProposition("prop2", this.p.parse("a & b & ~c"));
          assertThat(this.prop1.equals(this.prop1)).isTrue();
          assertThat(this.prop1.equals(prop11)).isTrue();
          assertThat(this.prop2.equals(prop21)).isTrue();
          assertThat(this.prop1.equals(this.prop2)).isFalse();
          assertThat(this.prop1.equals(null)).isFalse();
          assertThat(this.prop1.equals("String")).isFalse();
      }
  
      @Test
      public void testToString() {
          assertThat(this.prop1.toString()).isEqualTo("StandardProposition{formula=a & b, description=}");
          assertThat(this.prop2.toString()).isEqualTo("StandardProposition{formula=a & b & ~c, description=prop2}");
      }
  }
  