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🎉 PR 머지 완료! 🎉

build.gradle

@@ -11,9 +11,12 @@ repositories {
 
 dependencies {
     testImplementation platform('org.junit:junit-bom:5.9.1')
+    testImplementation platform('org.assertj:assertj-bom:3.25.1')
     testImplementation('org.junit.jupiter:junit-jupiter')
+    testImplementation('org.assertj:assertj-core')
 }
 
+
 test {
     useJUnitPlatform()
 }

src/main/java/Calculator.java

@@ -0,0 +1,24 @@
+public class Calculator {
+    //Basic Calculator
+    //인자 2개를 받아 정수 결과를 반환
+    //사칙연산을 위한 메서드 4개를 제공
+
+    public int add(int left, int right){
+        return left+right;
+    }
+
+    public int sub(int left, int right){
+        return left-right;
+    }
+
+    public int mul(int left, int right){
+        return left*right;
+    }
+
+    public int div(int left, int right){
+        if(right == 0){ //우변이 0인 경우 -> 0으로 나누는 문제
+            throw new RuntimeException("0으로는 나눌 수 없습니다");
+        }
+        return left/right;
+    }
+}

src/main/java/StringCalculator.java

@@ -0,0 +1,69 @@
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+public class StringCalculator {
+
+
+    public int addAll(String input) {
+
+        //빈 문자열 처리
+        if(input == null || input.isEmpty()) return 0;
+
+        //기본 구분자 정규표현식 (, 또는 :)
+        String regex = "[,|:]";
+
+        //커스텀 구분자를 사용하는 경우
+        if (input.startsWith("//")) {
+            //잘못된 구문에 대한 예외 처리
+            int formatEndIndex = input.indexOf("\n");
+            if (formatEndIndex == -1){ // "\n" 을 찾을 수 없는 경우
+                throw new RuntimeException("올바르지 않은 커스텀 구분자 지정 구문입니다.");
+            }
+
+            regex = "[,|:|" + Pattern.quote(input.substring(2, formatEndIndex)) + "]"; //Pattern.quote를 이용하여 특수문자를 안전하게 처리
+            input = input.substring(formatEndIndex+1); //커스텀 구분자 지정하는 부분을 제거
+
+        }else if(input.contains("\n"))
+        {
+            // "\n"은 있지만 "//"으로 시작하지 않는 경우에 RuntimeException 던지기
+            throw new RuntimeException("올바르지 않은 커스텀 구분자 지정 구문입니다.");
+        }
+
+        return calculateSum(input,regex);
+    }
+
+    private int calculateSum(String numbers, String regex) {
+        String[] tokens = numbers.split(regex);
+
+        List<Integer> parsedNumbers = new ArrayList<>();
+
+        for(String token : tokens){
+            try{
+                int parsedNumber = Integer.parseInt(token);
+                if(parsedNumber < 0){
+                    throw new RuntimeException("음수가 입력되었습니다.");
+                }
+
+                parsedNumbers.add(parsedNumber);
+            }catch (NumberFormatException e){
+                throw new RuntimeException("숫자 이외의 값이 입력되었습니다.");
+            }
+        }
+
+        //숫자를 모두 더해 반환
+        int result = 0;
+        for(int number : parsedNumbers){
+            try{
+                result = Math.addExact(result,number); //Math.addExact 정적 메서드로 오버플로우 발생 시 예외 처리
+            }catch(ArithmeticException e){
+                throw new RuntimeException("계산 결과값이 너무 큽니다.");
+            }
+
+        }
+        return result;
+
+
+    }
+
+}

src/test/java/TestCalculator.java

@@ -0,0 +1,56 @@
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Nested;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+
+@DisplayName("초간단 계산기 단위 테스트")
+public class TestCalculator {
+
+    Calculator calculator = new Calculator();
+
+    @Nested
+    @DisplayName("초간단 계산기 기능별 단위 테스트")
+    class CalculateFeatureTest {
+        @Test
+        @DisplayName("덧셈 테스트")
+        void testAdd(){
+            assertEquals(5, calculator.add(2 ,3));
+            assertEquals(8, calculator.add(-2 ,10));
+            assertEquals(-4,calculator.add(6,-10));
+            assertEquals(-10, calculator.add(-4,-6));
+        }
+
+        @Test
+        @DisplayName("뺄셈 테스트")
+        void testSub(){
+            assertEquals(-1, calculator.sub(2 ,3));
+            assertEquals(-12, calculator.sub(-2 ,10));
+            assertEquals(16,calculator.sub(6,-10));
+            assertEquals(2, calculator.sub(-4,-6));
+        }
+
+        @Test
+        @DisplayName("곱셈 테스트")
+        void testMul(){
+            assertEquals(6, calculator.mul(2 ,3));
+            assertEquals(-20, calculator.mul(-2 ,10));
+            assertEquals(-60, calculator.mul(6,-10));
+            assertEquals(24, calculator.mul(-4,-6));
+        }
+
+        @Test
+        @DisplayName("나눗셈 테스트")
+        void testDiv(){
+            assertEquals(0, calculator.div(2 ,3));
+            assertEquals(1, calculator.div(3 ,2));
+            assertEquals(-1, calculator.div(3,-2));
+            assertEquals(2, calculator.div(-4,-2));
+            assertEquals(0, calculator.div(0,-10));
+            //0으로 나누는 예외
+            assertThrows(RuntimeException.class, () -> calculator.div(6,0));
+
+        }
+    }
+}

src/test/java/TestCalculatorAssertJ.java

@@ -0,0 +1,90 @@
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Nested;
+
+import static org.assertj.core.api.Assertions.*;
+
+
+public class TestCalculatorAssertJ {
+    Calculator calculator = new Calculator();
+
+    @Nested
+    @DisplayName("초간단 계산기 기능별 단위 테스트")
+    class CalculateFeatureTestAssertJ {
+        @Test
+        @DisplayName("덧셈 테스트")
+        void testAdd(){
+            /*
+            assertEquals(5, calculator.add(2 ,3));
+            assertEquals(8, calculator.add(-2 ,10));
+            assertEquals(-4,calculator.add(6,-10));
+            assertEquals(-10, calculator.add(-4,-6));
+            */
+            assertThat(5).isEqualTo(calculator.add(2,3));
+            assertThat(8).isEqualTo(calculator.add(-2,10));
+            assertThat(-4).isEqualTo(calculator.add(6,-10));
+            assertThat(-10).isEqualTo(calculator.add(-4,-6));
+
+        }
+
+        @Test
+        @DisplayName("뺄셈 테스트")
+        void testSub(){
+            /*
+            assertEquals(-1, calculator.sub(2 ,3));
+            assertEquals(-12, calculator.sub(-2 ,10));
+            assertEquals(16,calculator.sub(6,-10));
+            assertEquals(2, calculator.sub(-4,-6));
+
+             */
+
+            assertThat(-1).isEqualTo(calculator.sub(2,3));
+            assertThat(-12).isEqualTo(calculator.sub(-2,10));
+            assertThat(16).isEqualTo(calculator.sub(6,-10));
+            assertThat(2).isEqualTo(calculator.sub(-4,-6));
+        }
+
+        @Test
+        @DisplayName("곱셈 테스트")
+        void testMul(){
+            /*
+            assertEquals(6, calculator.mul(2 ,3));
+            assertEquals(-20, calculator.mul(-2 ,10));
+            assertEquals(-60, calculator.mul(6,-10));
+            assertEquals(24, calculator.mul(-4,-6));
+
+             */
+
+            assertThat(6).isEqualTo(calculator.mul(2,3));
+            assertThat(-20).isEqualTo(calculator.mul(-2,10));
+            assertThat(-60).isEqualTo(calculator.mul(6,-10));
+            assertThat(24).isEqualTo(calculator.mul(-4,-6));
+
+        }
+
+        @Test
+        @DisplayName("나눗셈 테스트")
+        void testDiv(){
+            /*
+            assertEquals(0, calculator.div(2 ,3));
+            assertEquals(1, calculator.div(3 ,2));
+            assertEquals(-1, calculator.div(3,-2));
+            assertEquals(2, calculator.div(-4,-2));
+            assertEquals(0, calculator.div(0,-10));
+            //0으로 나누는 예외
+            assertThrows(RuntimeException.class, () -> calculator.div(6,0));
+
+             */
+
+            assertThat(0).isEqualTo(calculator.div(2,3));
+            assertThat(1).isEqualTo(calculator.div(3,2));
+            assertThat(-1).isEqualTo(calculator.div(3,-2));
+            assertThat(2).isEqualTo(calculator.div(-4,-2));
+            assertThat(0).isEqualTo(calculator.div(0,-10));
+
+            //0으로 나누는 예외
+            assertThatThrownBy(() -> calculator.div(6,0));
+
+        }
+    }
+}

src/test/java/TestStringCalculator.java

@@ -0,0 +1,68 @@
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Nested;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+
+@DisplayName("문자열 계산기 단위 테스트")
+public class TestStringCalculator {
+
+    StringCalculator stringCalculator = new StringCalculator();
+
+    @Nested
+    @DisplayName("문자열 계산기 기능 테스트")
+    class StringCalculatorFeatureTest {
+
+        @Test
+        @DisplayName("빈 문자열 케이스")
+        void testEmptyString(){
+            assertEquals(0, stringCalculator.addAll(""));
+        }
+
+        @Test
+        @DisplayName("올바른 입력 케이스")
+        void testValidInputs(){
+            //기본 구분자 사용
+            assertEquals(10,stringCalculator.addAll("1:2:3:4"));
+            assertEquals(10,stringCalculator.addAll("1,2,3,4"));
+            assertEquals(6,stringCalculator.addAll("1,2,3"));
+            assertEquals(6,stringCalculator.addAll("1:2:3"));
+            assertEquals(3,stringCalculator.addAll("1,2"));
+            assertEquals(3,stringCalculator.addAll("1:2"));
+            assertEquals(1,stringCalculator.addAll("1"));
+
+            //커스텀 구분자 사용
+            assertEquals(10,stringCalculator.addAll("//;\n1;2;3;4"));
+            assertEquals(6,stringCalculator.addAll("//;\n1;2;3"));
+            assertEquals(3,stringCalculator.addAll("//;\n1;2"));
+            assertEquals(1,stringCalculator.addAll("//;\n1"));
+
+            assertEquals(10,stringCalculator.addAll("//^\n1^2^3^4"));
+            assertEquals(6,stringCalculator.addAll("//^\n1^2^3"));
+            assertEquals(3,stringCalculator.addAll("//^\n1^2"));
+            assertEquals(1,stringCalculator.addAll("//^\n1"));
+        }
+
+        @Test
+        @DisplayName("RuntimeException 발생 케이스")
+        void testRuntimeException() {
+            //숫자 이외의 값
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("1,a,3"));
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("1:a:3"));
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("//^\n1^a^3"));
+
+            //음수 입력 케이스
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("1,-2,3"));
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("1:-2:3"));
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("//^\n1^-2^3"));
+
+            //잘못된 커스텀 지정자 구문
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("//;\t1;2;3"));
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("//;1;2;3"));
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("1^2^3"));
+            assertThrows(RuntimeException.class, () -> stringCalculator.addAll("^\n1^2^3"));
+
+        }
+    }
+}