From 5255b65f12d4139f0e9b97497e308c14525dfe25 Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 15:53:53 +0900
Subject: [PATCH 01/13] =?UTF-8?q?docs:=20README.md=20=EC=9E=91=EC=84=B1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/README.md b/README.md
index 22621e3..7a97609 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,38 @@
 # Calculator
+
+## 📌 구현 기능 목록
+
+### 입력받기
+
+"수식을 입력해주세요." &larr; 사용자에게 문구 출력
+
+입력 받기
+
+### 로직
+
+#### 입력 검사
+
+##### 통과
+
+- 공백은 0
+- 연산방향은 왼쪽에서 오른쪽  
+- (연산자 우선순위)
+
+##### 에러
+
+`IllegalArgumentException`
+
+- 연속된 연산자
+- 타입 에러
+
+
+
+### 출력
+
+#### 정상 출력
+
+"결과 : ?"
+
+#### 에러 발생
+
+"[ERROR] 잘못된 수식입니다. 입력 형식을 확인해 주세요."
\ No newline at end of file

From 33a318a970248cbe7d7ab1c88a0048f3a4def4fe Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 16:24:58 +0900
Subject: [PATCH 02/13] =?UTF-8?q?feat:=20Console=20=ED=81=B4=EB=9E=98?=
 =?UTF-8?q?=EC=8A=A4=20=EC=B4=88=EA=B8=B0=ED=99=94?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/calculator/Console.java | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 src/main/java/calculator/Console.java

diff --git a/src/main/java/calculator/Console.java b/src/main/java/calculator/Console.java
new file mode 100644
index 0000000..5ecbf64
--- /dev/null
+++ b/src/main/java/calculator/Console.java
@@ -0,0 +1,20 @@
+package calculator;
+
+import java.util.Scanner;
+
+// 입출력 책임
+public class Console {
+    private static final String MESSAGE_INPUT_GUIDE = "수식을 입력해주세요.";
+    private static final String MESSAGE_OUTPUT_FORMATTED = "결과 : %d";
+    private static final String MESSAGE_ERROR_FORMAT = "[ERROR] 잘못된 수식입니다. 입력 형식을 확인해 주세요.";
+
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public String readInput() {
+        // TODO: 입력 안내 출력 후 입력 받기
+        return null;
+    }
+    public void printResult() {
+        // TODO: 결과값 출력
+    }
+}

From 0c00d64706470b10bcc6e14a8d6860a23447e216 Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 16:36:31 +0900
Subject: [PATCH 03/13] =?UTF-8?q?feat:=20readInput()=20=EA=B5=AC=ED=98=84?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/calculator/Console.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/java/calculator/Console.java b/src/main/java/calculator/Console.java
index 5ecbf64..3222f1b 100644
--- a/src/main/java/calculator/Console.java
+++ b/src/main/java/calculator/Console.java
@@ -11,8 +11,8 @@ public class Console {
     private static final Scanner scanner = new Scanner(System.in);
 
     public String readInput() {
-        // TODO: 입력 안내 출력 후 입력 받기
-        return null;
+        System.out.println(MESSAGE_INPUT_GUIDE);
+        return scanner.nextLine();
     }
     public void printResult() {
         // TODO: 결과값 출력

From 96f54f96d71f1d6859fd6fde05ea256fde271bfc Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 16:37:32 +0900
Subject: [PATCH 04/13] =?UTF-8?q?refactor:=20printResult()=EC=9D=98=20?=
 =?UTF-8?q?=EC=8B=9C=EA=B7=B8=EB=8B=88=EC=B2=98=20=EB=B3=80=EA=B2=BD=20(?=
 =?UTF-8?q?=EA=B2=B0=EA=B3=BC=EA=B0=92=20=EB=A7=A4=EA=B0=9C=EB=B3=80?=
 =?UTF-8?q?=EC=88=98=20=EC=B6=94=EA=B0=80)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/calculator/Console.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/calculator/Console.java b/src/main/java/calculator/Console.java
index 3222f1b..267bf57 100644
--- a/src/main/java/calculator/Console.java
+++ b/src/main/java/calculator/Console.java
@@ -14,7 +14,7 @@ public String readInput() {
         System.out.println(MESSAGE_INPUT_GUIDE);
         return scanner.nextLine();
     }
-    public void printResult() {
+    public void printResult(int result) {
         // TODO: 결과값 출력
     }
 }

From dda7b8355dbb7bf8d36f910b9a6284d41ff616f3 Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 16:40:13 +0900
Subject: [PATCH 05/13] =?UTF-8?q?feat:=20printResult()=20=EA=B5=AC?=
 =?UTF-8?q?=ED=98=84?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/calculator/Console.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/calculator/Console.java b/src/main/java/calculator/Console.java
index 267bf57..e0af88b 100644
--- a/src/main/java/calculator/Console.java
+++ b/src/main/java/calculator/Console.java
@@ -15,6 +15,6 @@ public String readInput() {
         return scanner.nextLine();
     }
     public void printResult(int result) {
-        // TODO: 결과값 출력
+        System.out.println(String.format(MESSAGE_OUTPUT_FORMATTED, result));
     }
 }

From 27fa767b963ae1c071b83fa0148119725ae490b3 Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 22:59:03 +0900
Subject: [PATCH 06/13] =?UTF-8?q?feat(Console.java):=20=EC=97=90=EB=9F=AC?=
 =?UTF-8?q?=20=EB=A9=94=EC=84=B8=EC=A7=80=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/calculator/Console.java | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/main/java/calculator/Console.java b/src/main/java/calculator/Console.java
index e0af88b..d866049 100644
--- a/src/main/java/calculator/Console.java
+++ b/src/main/java/calculator/Console.java
@@ -2,11 +2,16 @@
 
 import java.util.Scanner;
 
+// TODO: SINGLETON?
 // 입출력 책임
 public class Console {
     private static final String MESSAGE_INPUT_GUIDE = "수식을 입력해주세요.";
     private static final String MESSAGE_OUTPUT_FORMATTED = "결과 : %d";
-    private static final String MESSAGE_ERROR_FORMAT = "[ERROR] 잘못된 수식입니다. 입력 형식을 확인해 주세요.";
+
+    public static final String MESSAGE_ERROR_FORMAT = "[ERROR] 잘못된 수식입니다. 입력 형식을 확인해 주세요.";
+    public static final String MESSAGE_ERROR_CONSECUTIVE_OPERATORS = "[ERROR] 잘못된 수식입니다. 입력 형식을 확인해 주세요.";
+    public static final String MESSAGE_ERROR_EMPTY_OR_BLANK = "[ERROR] 입력값이 없거나 공백입니다. 입력 형식을 확인해 주세요.";
+
 
     private static final Scanner scanner = new Scanner(System.in);
 
@@ -14,6 +19,7 @@ public String readInput() {
         System.out.println(MESSAGE_INPUT_GUIDE);
         return scanner.nextLine();
     }
+
     public void printResult(int result) {
         System.out.println(String.format(MESSAGE_OUTPUT_FORMATTED, result));
     }

From b2e910c6fdcbfd5a8bac472b0be3ea72bfbd6e74 Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 22:59:18 +0900
Subject: [PATCH 07/13] =?UTF-8?q?feat:=20Validator=20=ED=81=B4=EB=9E=98?=
 =?UTF-8?q?=EC=8A=A4=20=EA=B5=AC=ED=98=84?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/calculator/Validator.java | 63 +++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/main/java/calculator/Validator.java

diff --git a/src/main/java/calculator/Validator.java b/src/main/java/calculator/Validator.java
new file mode 100644
index 0000000..a29ac70
--- /dev/null
+++ b/src/main/java/calculator/Validator.java
@@ -0,0 +1,63 @@
+package calculator;
+
+import java.util.ArrayList;
+import java.util.Set;
+
+// 검사 책임
+
+public class Validator {
+
+    // 검사를 위한 배열 생성
+    private final ArrayList<String> inputArrayList = new ArrayList<>();
+    // 검사를 위한 연산자 set
+    private static final Set<Character> OPERATORS = Set.of('+', '-', '*', '/');
+
+    // 검사 이후 숫자와 연산자로 쪼개어 배열로 return
+    public ArrayList<String> divideInput(String input) {
+        String currentNumber = "";
+
+        validateEmptyOrBlank(input);
+
+        for (int i = 0; i < input.length(); i++) {
+            char ch = input.charAt(i);
+
+            if (Character.isDigit(ch)) {
+                currentNumber += ch;
+
+                validateLastNumber(i, input.length() - 1, currentNumber);
+
+            } else if (OPERATORS.contains(ch)) {
+                validateConsecutiveOperators(currentNumber);
+
+                inputArrayList.add(currentNumber);
+                inputArrayList.add(String.valueOf(ch));
+
+                currentNumber = "";
+
+            } else {  // 숫자나 문자열이 아닌 경우
+                throw new IllegalArgumentException(Console.MESSAGE_ERROR_FORMAT);
+            }
+        }
+
+        return inputArrayList;
+    }
+
+    private void validateLastNumber(int position, int length, String currentNumber) {
+        if (position == length) {
+            inputArrayList.add(currentNumber);
+        }
+    }
+
+    private void validateEmptyOrBlank(String input) {
+        if (input.isBlank()) {
+            throw new IllegalStateException(Console.MESSAGE_ERROR_EMPTY_OR_BLANK);
+        }
+    }
+
+    private void validateConsecutiveOperators(String currentNumber) {
+        if (currentNumber.isEmpty()) {
+            throw new IllegalArgumentException(Console.MESSAGE_ERROR_CONSECUTIVE_OPERATORS);
+        }
+    }
+
+}

From 27cc1fca82def5ae1d44ad9e83b3846176255f3d Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 23:00:12 +0900
Subject: [PATCH 08/13] =?UTF-8?q?feat:=20Calculator=20=ED=81=B4=EB=9E=98?=
 =?UTF-8?q?=EC=8A=A4=20=EA=B5=AC=ED=98=84?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/calculator/Calculator.java | 56 +++++++++++++++++++++---
 1 file changed, 49 insertions(+), 7 deletions(-)

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index 88e8552..b54a18a 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -1,13 +1,55 @@
 package calculator;
 
-/*
-    1주차에만 제공되는 예시 코드입니다.
-    코드는 그대로 사용해도 되고 수정해도 됩니다.
- */
+import java.util.*;
 
+// 연산 책임
 public class Calculator {
-    public int calculate(String input) {
-        // TODO: 코드 구현
-        throw new IllegalArgumentException("아직 구현되지 않았습니다.");
+
+    private int result = 0;
+
+    public int calculate(ArrayList<String> inputArrayList) {
+
+        // 단일 원소인 경우 그대로 return
+        if (isSingleElement(inputArrayList)) {
+            return Integer.parseInt(inputArrayList.get(0));
+        }
+
+        // 큐 선언
+        LinkedList<String> stringQueue = toQueue(inputArrayList);
+
+        while (stringQueue.size() > 1) {
+
+            result = operate(
+                    stringQueue.poll(),
+                    stringQueue.poll(),
+                    stringQueue.poll()
+            );
+
+            stringQueue.addFirst(String.valueOf(result));
+        }
+
+        return result;
+    }
+
+
+    private boolean isSingleElement(ArrayList<String> inputArrayList) {
+        return inputArrayList.size() == 1;
+    }
+
+    private LinkedList<String> toQueue(ArrayList<String> inputArrayList) {
+        return new LinkedList<>(inputArrayList);
+    }
+
+    private int operate(String num1String, String operator, String num2String) {
+        int num1 = Integer.parseInt(num1String);
+        int num2 = Integer.parseInt(num2String);
+
+        return switch (operator) {
+            case "+" -> num1 + num2;
+            case "-" -> num1 - num2;
+            case "*" -> num1 * num2;
+            case "/" -> num1 / num2;
+            default -> throw new IllegalStateException("Unexpected value: " + operator);
+        };
     }
 }

From 847f8e1e8e5e399c2f8cde7c0ee9148cf3a1d31b Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 23:01:50 +0900
Subject: [PATCH 09/13] =?UTF-8?q?feat:=20Application=20=ED=81=B4=EB=9E=98?=
 =?UTF-8?q?=EC=8A=A4=20=EA=B5=AC=ED=98=84?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

간편한 통합테스트를 위한
- run() 메서드 분리
- int 반환값
---
 src/main/java/calculator/Application.java | 30 ++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/main/java/calculator/Application.java b/src/main/java/calculator/Application.java
index d909a50..388237e 100644
--- a/src/main/java/calculator/Application.java
+++ b/src/main/java/calculator/Application.java
@@ -1,11 +1,35 @@
 package calculator;
 
+import java.util.ArrayList;
+
 public class Application {
+
+    private static final Console console = new Console();
+
     public static void main(String[] args) {
-        // TODO: 코드 작성
+        String inputString = console.readInput();
+
+        run(inputString);
+    }
 
-        // 예시 코드
+    public static int run(String inputString) {
+        Validator validator = new Validator();
         Calculator calculator = new Calculator();
-        calculator.calculate("");
+
+        ArrayList<String> inputArrayList;
+        int result = 0;
+
+        try {
+            inputArrayList = validator.divideInput(inputString);
+            result = calculator.calculate(inputArrayList);
+        } catch (IllegalStateException e) {
+            // 입력값이 공백값 또는 비어있는 경우
+        } catch (IllegalArgumentException illegalArgumentException) {
+            System.out.println(illegalArgumentException.getMessage());
+            return -1;
+        }
+
+        console.printResult(result);
+        return result;
     }
 }

From 445cbb5724a1b596c0f3d942226d9cb5bd0482ca Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 23:09:20 +0900
Subject: [PATCH 10/13] =?UTF-8?q?test(ApplicationTest.java):=20Application?=
 =?UTF-8?q?=20=EC=BD=94=EB=93=9C=EC=97=90=20=EB=A7=9E=EA=B2=8C=20=ED=85=8C?=
 =?UTF-8?q?=EC=8A=A4=ED=8A=B8=EC=BD=94=EB=93=9C=20=EC=88=98=EC=A0=95?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/test/java/calculator/ApplicationTest.java | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/src/test/java/calculator/ApplicationTest.java b/src/test/java/calculator/ApplicationTest.java
index f3e71c7..4a9e3d1 100644
--- a/src/test/java/calculator/ApplicationTest.java
+++ b/src/test/java/calculator/ApplicationTest.java
@@ -1,36 +1,31 @@
 package calculator;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import org.junit.jupiter.api.Test;
 
+
 public class ApplicationTest {
-    Calculator calculator = new Calculator();
 
     @Test
     public void 빈_문자열_입력_시_0을_반환한다() {
-        // 아직 calculate 함수가 구현되지 않은 상태에서 TDD Red Test용 코드
-        int result = calculator.calculate("");
-        assertThat(result).isEqualTo(0);
+        assertThat(Application.run("   ")).isEqualTo(0);
     }
 
     @Test
     public void 덧셈과_뺄셈만_포함된_수식_계산() {
-        int result = calculator.calculate("1+2-3");
-        assertThat(result).isEqualTo(0);
+        assertThat(Application.run("1+2-3")).isEqualTo(0);
     }
 
     @Test
     public void 곱셈과_덧셈_포함_수식_계산() {
-        int result = calculator.calculate("2*3+4");
-        assertThat(result).isEqualTo(10);
+        assertThat(Application.run("2*3+4")).isEqualTo(10);
+
     }
 
     @Test
     public void 잘못된_수식_입력_시_예외_발생() {
-        assertThrows(IllegalArgumentException.class, () -> {
-            calculator.calculate("1++2");
-        });
+        assertThat(Application.run("1++2")).isEqualTo(-1);
     }
 
     // TODO: 테스트 코드 추가 가능합니다.

From 9a04f07aa77cd7018f2f751848c60a11649d1c0c Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 23:34:41 +0900
Subject: [PATCH 11/13] =?UTF-8?q?test:=20ValidatorTest=20=EC=9E=91?=
 =?UTF-8?q?=EC=84=B1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/test/java/calculator/ValidatorTest.java | 55 +++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 src/test/java/calculator/ValidatorTest.java

diff --git a/src/test/java/calculator/ValidatorTest.java b/src/test/java/calculator/ValidatorTest.java
new file mode 100644
index 0000000..1943527
--- /dev/null
+++ b/src/test/java/calculator/ValidatorTest.java
@@ -0,0 +1,55 @@
+package calculator;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class ValidatorTest {
+
+    Validator validator = new Validator();
+
+    @Test
+    void split_test() {
+        String input = "3+5*2";
+        List<String> result = validator.divideInput(input);
+
+        assertThat(result).containsExactly("3", "+", "5", "*", "2");
+    }
+
+    @Test
+    void exception_test_for_blank() {
+        String input = "   ";
+        Exception e = assertThrows(IllegalStateException.class, () -> validator.divideInput(input));
+
+        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_EMPTY_OR_BLANK);
+    }
+
+    @Test
+    void exception_test_for_operators() {
+        String input = "3++2";
+        Exception e = assertThrows(IllegalArgumentException.class, () -> validator.divideInput(input));
+
+        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_CONSECUTIVE_OPERATORS);
+    }
+
+    @Test
+    void exception_test_for_input_format() {
+        String input = "5+a";
+        Exception e = assertThrows(IllegalArgumentException.class, () -> validator.divideInput(input));
+
+        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_FORMAT);
+    }
+
+    @Test
+    void exception_test_for_first_starts_with_operator() {
+        String input = "+12+3-5";
+        Exception e = assertThrows(IllegalArgumentException.class, () -> validator.divideInput(input));
+
+        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_CONSECUTIVE_OPERATORS);
+
+    }
+
+}

From 23212aa9fc6b4b45e6df6ae46b714f82d7ad38bf Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 23:40:14 +0900
Subject: [PATCH 12/13] =?UTF-8?q?refactor:=20=EC=97=B0=EC=82=B0=EC=9E=90?=
 =?UTF-8?q?=20=EC=9C=84=EC=B9=98=EC=97=90=20=EB=8C=80=ED=95=9C=20=EB=A9=94?=
 =?UTF-8?q?=EC=84=9C=EB=93=9C=20=EB=B0=8F=20=EC=97=90=EB=9F=AC=EB=A9=94?=
 =?UTF-8?q?=EC=84=B8=EC=A7=80=EB=AA=85=20=EB=B3=80=EA=B2=BD?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

validateConsecutiveOperators() -> validateOperatorPosition()
MESSAGE_ERROR_CONSECUTIVE_OPERATORS -> MESSAGE_ERROR_WRONG_POSITION_OPERATORS

연속적인 연산자인 경우 뿐만 아니라 연산자가 처음 입력되는 경우에도 같은 분기로 처리되므로 적절한 이름으로 변경하였습니다.
---
 src/main/java/calculator/Console.java       | 2 +-
 src/main/java/calculator/Validator.java     | 6 +++---
 src/test/java/calculator/ValidatorTest.java | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/main/java/calculator/Console.java b/src/main/java/calculator/Console.java
index d866049..aef9bd4 100644
--- a/src/main/java/calculator/Console.java
+++ b/src/main/java/calculator/Console.java
@@ -9,7 +9,7 @@ public class Console {
     private static final String MESSAGE_OUTPUT_FORMATTED = "결과 : %d";
 
     public static final String MESSAGE_ERROR_FORMAT = "[ERROR] 잘못된 수식입니다. 입력 형식을 확인해 주세요.";
-    public static final String MESSAGE_ERROR_CONSECUTIVE_OPERATORS = "[ERROR] 잘못된 수식입니다. 입력 형식을 확인해 주세요.";
+    public static final String MESSAGE_ERROR_WRONG_POSITION_OPERATORS = "[ERROR] 잘못된 연산자 위치입니다. 입력 형식을 확인해 주세요.";
     public static final String MESSAGE_ERROR_EMPTY_OR_BLANK = "[ERROR] 입력값이 없거나 공백입니다. 입력 형식을 확인해 주세요.";
 
 
diff --git a/src/main/java/calculator/Validator.java b/src/main/java/calculator/Validator.java
index a29ac70..c31e32f 100644
--- a/src/main/java/calculator/Validator.java
+++ b/src/main/java/calculator/Validator.java
@@ -27,7 +27,7 @@ public ArrayList<String> divideInput(String input) {
                 validateLastNumber(i, input.length() - 1, currentNumber);
 
             } else if (OPERATORS.contains(ch)) {
-                validateConsecutiveOperators(currentNumber);
+                validateOperatorPosition(currentNumber);
 
                 inputArrayList.add(currentNumber);
                 inputArrayList.add(String.valueOf(ch));
@@ -54,9 +54,9 @@ private void validateEmptyOrBlank(String input) {
         }
     }
 
-    private void validateConsecutiveOperators(String currentNumber) {
+    private void validateOperatorPosition(String currentNumber) {
         if (currentNumber.isEmpty()) {
-            throw new IllegalArgumentException(Console.MESSAGE_ERROR_CONSECUTIVE_OPERATORS);
+            throw new IllegalArgumentException(Console.MESSAGE_ERROR_WRONG_POSITION_OPERATORS);
         }
     }
 
diff --git a/src/test/java/calculator/ValidatorTest.java b/src/test/java/calculator/ValidatorTest.java
index 1943527..cea3a1c 100644
--- a/src/test/java/calculator/ValidatorTest.java
+++ b/src/test/java/calculator/ValidatorTest.java
@@ -32,7 +32,7 @@ void exception_test_for_operators() {
         String input = "3++2";
         Exception e = assertThrows(IllegalArgumentException.class, () -> validator.divideInput(input));
 
-        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_CONSECUTIVE_OPERATORS);
+        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_WRONG_POSITION_OPERATORS);
     }
 
     @Test
@@ -48,7 +48,7 @@ void exception_test_for_first_starts_with_operator() {
         String input = "+12+3-5";
         Exception e = assertThrows(IllegalArgumentException.class, () -> validator.divideInput(input));
 
-        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_CONSECUTIVE_OPERATORS);
+        assertThat(e.getMessage()).isEqualTo(Console.MESSAGE_ERROR_WRONG_POSITION_OPERATORS);
 
     }
 

From 0fd697c757ee20901b22dbc35bfecb43f856889b Mon Sep 17 00:00:00 2001
From: HyunjeLee <cyeclamen07@gmail.com>
Date: Sat, 5 Apr 2025 23:40:34 +0900
Subject: [PATCH 13/13] =?UTF-8?q?test:=20CalculatorTest=20=EC=9E=91?=
 =?UTF-8?q?=EC=84=B1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/test/java/calculator/CalculatorTest.java | 53 ++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 src/test/java/calculator/CalculatorTest.java

diff --git a/src/test/java/calculator/CalculatorTest.java b/src/test/java/calculator/CalculatorTest.java
new file mode 100644
index 0000000..aa7fddf
--- /dev/null
+++ b/src/test/java/calculator/CalculatorTest.java
@@ -0,0 +1,53 @@
+package calculator;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class CalculatorTest {
+
+    Calculator calculator = new Calculator();
+
+    @Test
+    void calculate_test_single() {
+        ArrayList<String> input = new ArrayList<>(List.of("12"));
+        int result = calculator.calculate(input);
+
+        assertThat(result).isEqualTo(12);
+    }
+
+    @Test
+    void calculate_test_simple() {
+        ArrayList<String> input = new ArrayList<>(List.of("1", "+", "2"));
+        int result = calculator.calculate(input);
+
+        assertThat(result).isEqualTo(3);
+    }
+
+    @Test
+    void calculate_test_divide() {
+        ArrayList<String> input = new ArrayList<>(List.of("4", "/", "2"));
+        int result = calculator.calculate(input);
+
+        assertThat(result).isEqualTo(2);
+    }
+
+    @Test
+    void calculate_test_complex() {
+        ArrayList<String> input = new ArrayList<>(List.of("2", "+", "3", "*", "4"));
+        int result = calculator.calculate(input);
+
+        assertThat(result).isEqualTo(20);
+    }
+
+    @Test
+    void calculate_test_wrong_operator() {
+        ArrayList<String> input = new ArrayList<>(List.of("1", "&", "2"));
+
+        assertThrows(IllegalStateException.class, () -> calculator.calculate(input));
+    }
+}