test: 중위 연산식을 입력 받아 계산하는 클래스 테스트 작성

Author: wonu606

calculator/src/main/java/com/wonu606/calculator/util/CalculatorMessage.java

@@ -3,7 +3,8 @@
 public enum CalculatorMessage {
     INVALID_ORDER("잘못된 순번입니다."),
     INVALID_INPUT("잘못된 입력입니다."),
-    NOT_DIVISIBLE_BY_ZERO("0으로 나눌 수 없습니다.");
+    NOT_DIVISIBLE_BY_ZERO("0으로 나눌 수 없습니다."),
+    OVERFLOW_OCCURS("계산 중 Overflow가 발생했습니다.");
 
     public final String message;
 

calculator/src/test/java/com/wonu606/calculator/strategy/CalculationStrategyTest.java

@@ -0,0 +1,135 @@
+package com.wonu606.calculator.strategy;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.wonu606.calculator.calculator.PostfixCalculator;
+import com.wonu606.calculator.converter.InfixToPostfixConverter;
+import com.wonu606.calculator.storage.ResultStore;
+import com.wonu606.calculator.util.CalculatorMessage;
+import com.wonu606.calculator.validator.InfixValidator;
+import com.wonu606.io.ConsoleInput;
+import com.wonu606.io.ConsolePrinter;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.io.PrintStream;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+class CalculationStrategyTest {
+
+    @Test
+    @DisplayName("정상 입력")
+    void testNormalInput() {
+        // given
+        CalculatorStrategy calculator = new CalculationStrategy(
+                new InfixValidator(), new InfixToPostfixConverter(), new PostfixCalculator());
+
+        String expression = "2 + 3";
+        InputStream in = new ByteArrayInputStream(expression.getBytes());
+        System.setIn(in);
+
+        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+        PrintStream out = System.out;
+        System.setOut(new PrintStream(outContent));
+
+        // when
+        calculator.execute(new ConsoleInput(), new ConsolePrinter(), new ResultStore());
+
+        // then
+        String expectedResult = 5 + "\n";
+        assertThat(expectedResult).isEqualTo(outContent.toString());
+    }
+
+    @Test
+    @DisplayName("Double 오버 플로우 발생")
+    void testDoubleOverflowOccurs() {
+        // given
+        CalculatorStrategy calculator = new CalculationStrategy(
+                new InfixValidator(), new InfixToPostfixConverter(), new PostfixCalculator());
+
+        String expression = Double.MAX_VALUE + " + 1";
+        InputStream in = new ByteArrayInputStream(expression.getBytes());
+        System.setIn(in);
+
+        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+        PrintStream out = System.out;
+        System.setOut(new PrintStream(outContent));
+
+        // when
+        calculator.execute(new ConsoleInput(), new ConsolePrinter(), new ResultStore());
+
+        // then
+        String expectedResult = CalculatorMessage.OVERFLOW_OCCURS.message + "\n";
+        assertThat(expectedResult).isEqualTo(outContent.toString());
+    }
+
+    @Test
+    @DisplayName("Integer 오버 플로우 발생")
+    void testIntegerOverflowOccurs() {
+        // given
+        CalculatorStrategy calculator = new CalculationStrategy(
+                new InfixValidator(), new InfixToPostfixConverter(), new PostfixCalculator());
+
+        String expression = Integer.MAX_VALUE + " + 1";
+        InputStream in = new ByteArrayInputStream(expression.getBytes());
+        System.setIn(in);
+
+        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+        PrintStream out = System.out;
+        System.setOut(new PrintStream(outContent));
+
+        // when
+        calculator.execute(new ConsoleInput(), new ConsolePrinter(), new ResultStore());
+
+        // then
+        String expectedResult = CalculatorMessage.OVERFLOW_OCCURS.message + "\n";
+        assertThat(expectedResult).isEqualTo(outContent.toString());
+    }
+
+    @Test
+    @DisplayName("0으로 나눌 경우 오류 발생")
+    void testDividedByZero() {
+        // given
+        CalculatorStrategy calculator = new CalculationStrategy(
+                new InfixValidator(), new InfixToPostfixConverter(), new PostfixCalculator());
+
+        String expression = "10 / 0";
+        InputStream in = new ByteArrayInputStream(expression.getBytes());
+        System.setIn(in);
+
+        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+        PrintStream out = System.out;
+        System.setOut(new PrintStream(outContent));
+
+        // when
+        calculator.execute(new ConsoleInput(), new ConsolePrinter(), new ResultStore());
+
+        // then
+        String expectedResult = CalculatorMessage.NOT_DIVISIBLE_BY_ZERO.message + "\n";
+        assertThat(expectedResult).isEqualTo(outContent.toString());
+    }
+
+    @Test
+    @DisplayName("중위 연산식이 아닌 경우")
+    void testIsNotInfixExpression() {
+        // given
+        CalculatorStrategy calculator = new CalculationStrategy(
+                new InfixValidator(), new InfixToPostfixConverter(), new PostfixCalculator());
+
+        String expression = "3 5 +";
+        InputStream in = new ByteArrayInputStream(expression.getBytes());
+        System.setIn(in);
+
+        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+        PrintStream out = System.out;
+        System.setOut(new PrintStream(outContent));
+
+        // when
+        calculator.execute(new ConsoleInput(), new ConsolePrinter(), new ResultStore());
+
+        // then
+        String expectedResult = CalculatorMessage.INVALID_INPUT.message + "\n";
+        assertThat(expectedResult).isEqualTo(outContent.toString());
+    }
+}