From fa3cd03fc6392b9254596e2a995cd637f3ad82e0 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 21:15:51 +0900
Subject: [PATCH 01/15] =?UTF-8?q?docs(readme):=20=EB=A6=AC=EB=93=9C?=
 =?UTF-8?q?=EB=AF=B8=20=EC=83=9D=EC=84=B1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 13420b29..aaf3363c 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,18 @@
-# javascript-calculator-precourse
\ No newline at end of file
+## ➕ 문자열 덧셈 계산기 체크리스트
+
+### 기능 구현
+
+- [ ] 빈 문자열 입력 시 `0` 반환
+- [ ] 기본 구분자 (`,` `:`) 로 숫자 분리
+- [ ] 커스텀 구분자 `"//<구분자>\n"` 형식 지원
+- [ ] 잘못된 입력 시 `[ERROR]` 메시지 출력
+- [ ] 양수만 허용
+- [ ] `Console.readLineAsync`, `Console.print` 사용
+- [ ] 출력 형식: `결과 : <합계>`
+
+### 예외 처리
+
+- [ ] 음수 입력 시 에러 발생
+- [ ] 숫자 아닌 값 입력 시 에러 발생
+- [ ] 잘못된 포맷 입력 시 에러 발생
+- [ ] 연속 구분자 처리 정책 반영

From ad16d2f9ab8560d30dbfb1a5859e966ea403a427 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:03:23 +0900
Subject: [PATCH 02/15] feat(app): add InputHandler logic

---
 src/App.js             | 7 ++++++-
 src/io/InputHandler.js | 7 +++++++
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 src/io/InputHandler.js

diff --git a/src/App.js b/src/App.js
index 091aa0a5..64ccda86 100644
--- a/src/App.js
+++ b/src/App.js
@@ -1,5 +1,10 @@
+import { readInput, printResult, printError } from "./io/InputHandler.js";
+
 class App {
-  async run() {}
+  async run() {
+    const input = await readInput();
+    const sum = calculateSum(input);
+  }
 }
 
 export default App;
diff --git a/src/io/InputHandler.js b/src/io/InputHandler.js
new file mode 100644
index 00000000..8c46cd1b
--- /dev/null
+++ b/src/io/InputHandler.js
@@ -0,0 +1,7 @@
+import { Console } from "@woowacourse/mission-utils";
+
+export async function readInput() {
+  Console.print("덧셈할 문자열을 입력해 주세요.");
+  const input = await Console.readLineAsync("");
+  return input;
+}

From f54e4281014e0bea62841af8a7615ed491074d91 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:04:13 +0900
Subject: [PATCH 03/15] feat(app): add print result logic

---
 src/App.js             | 1 +
 src/io/InputHandler.js | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/src/App.js b/src/App.js
index 64ccda86..5b9ffbd9 100644
--- a/src/App.js
+++ b/src/App.js
@@ -4,6 +4,7 @@ class App {
   async run() {
     const input = await readInput();
     const sum = calculateSum(input);
+    printResult(sum);
   }
 }
 
diff --git a/src/io/InputHandler.js b/src/io/InputHandler.js
index 8c46cd1b..fc0808e1 100644
--- a/src/io/InputHandler.js
+++ b/src/io/InputHandler.js
@@ -5,3 +5,6 @@ export async function readInput() {
   const input = await Console.readLineAsync("");
   return input;
 }
+export function printResult(result) {
+  Console.print(`결과 : <${result}>`);
+}

From 7f15d94ca68beccf8252d5c43532238981d82703 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:04:50 +0900
Subject: [PATCH 04/15] feat(app):add error handler logic

---
 src/App.js             | 10 +++++++---
 src/io/InputHandler.js |  4 ++++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/App.js b/src/App.js
index 5b9ffbd9..ab4dedd2 100644
--- a/src/App.js
+++ b/src/App.js
@@ -2,9 +2,13 @@ import { readInput, printResult, printError } from "./io/InputHandler.js";
 
 class App {
   async run() {
-    const input = await readInput();
-    const sum = calculateSum(input);
-    printResult(sum);
+    try {
+      const input = await readInput();
+      const sum = calculateSum(input);
+      printResult(sum);
+    } catch (err) {
+      printError(err);
+    }
   }
 }
 
diff --git a/src/io/InputHandler.js b/src/io/InputHandler.js
index fc0808e1..815c3e90 100644
--- a/src/io/InputHandler.js
+++ b/src/io/InputHandler.js
@@ -8,3 +8,7 @@ export async function readInput() {
 export function printResult(result) {
   Console.print(`결과 : <${result}>`);
 }
+export function printError(err) {
+  const m = err?.message ?? "알 수 없는 오류가 발생했습니다.";
+  Console.print(`[ERROR] ${m}`);
+}

From 85ad5130b76908eaa6877ed3ab82badffc9bd0bb Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:12:05 +0900
Subject: [PATCH 05/15] feat(Parser): return empty array when input string is
 empty

---
 src/calculator/Parser.js | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 src/calculator/Parser.js

diff --git a/src/calculator/Parser.js b/src/calculator/Parser.js
new file mode 100644
index 00000000..dda3bb3c
--- /dev/null
+++ b/src/calculator/Parser.js
@@ -0,0 +1,7 @@
+class Parser {
+  static parse(input) {
+    if (!input) return [];
+  }
+}
+
+export default Parser;

From 35fdad9bbfa7b466563baaf0f46690c77997571a Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:22:48 +0900
Subject: [PATCH 06/15] feat(parser): add base Parser class with default
 delimiters (, :)

---
 src/calculator/Parser.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/calculator/Parser.js b/src/calculator/Parser.js
index dda3bb3c..fa0b6ffe 100644
--- a/src/calculator/Parser.js
+++ b/src/calculator/Parser.js
@@ -1,6 +1,10 @@
 class Parser {
   static parse(input) {
     if (!input) return [];
+
+    const delimiters = [",", ":"];
+    const pattern = new RegExp(`[${delimiters.join("")}]`);
+    return input.split(pattern);
   }
 }
 

From a8d89a6f4eab16e4db8bdbb78e6cf18a8d0b9cd7 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:23:51 +0900
Subject: [PATCH 07/15] feat(parser): support custom delimiter syntax

---
 src/calculator/Parser.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/calculator/Parser.js b/src/calculator/Parser.js
index fa0b6ffe..01a2726e 100644
--- a/src/calculator/Parser.js
+++ b/src/calculator/Parser.js
@@ -2,9 +2,17 @@ class Parser {
   static parse(input) {
     if (!input) return [];
 
-    const delimiters = [",", ":"];
+    let delimiters = [",", ":"];
+    let expression = input;
+
+    const match = input.match(/^\/\/(.)\n/);
+    if (match) {
+      delimiters.push(match[1]);
+      expression = input.slice(match[0].length);
+    }
+
     const pattern = new RegExp(`[${delimiters.join("")}]`);
-    return input.split(pattern);
+    return expression.split(pattern);
   }
 }
 

From e32b2821189e1f3c43e90aaea47e76f70f37fdb7 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:24:25 +0900
Subject: [PATCH 08/15] feat(parser): add escapeForRegExp to safely handle
 special characters in delimiters

---
 src/calculator/Parser.js | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/calculator/Parser.js b/src/calculator/Parser.js
index 01a2726e..8f91afc2 100644
--- a/src/calculator/Parser.js
+++ b/src/calculator/Parser.js
@@ -1,17 +1,23 @@
 class Parser {
+  static escapeForRegExp(str) {
+    return str.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+  }
+
   static parse(input) {
     if (!input) return [];
 
     let delimiters = [",", ":"];
     let expression = input;
 
-    const match = input.match(/^\/\/(.)\n/);
-    if (match) {
-      delimiters.push(match[1]);
-      expression = input.slice(match[0].length);
+    const m = input.match(/^\/\/(.)\n/);
+    if (m) {
+      delimiters.push(m[1]);
+      expression = input.slice(m[0].length);
     }
 
-    const pattern = new RegExp(`[${delimiters.join("")}]`);
+    const pattern = new RegExp(
+      `[${Parser.escapeForRegExp(delimiters.join(""))}]`
+    );
     return expression.split(pattern);
   }
 }

From f05086b0a3a339c91e23eebc1d17eac9c474aa18 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:25:31 +0900
Subject: [PATCH 09/15] feat(calculator): add base calculateSum function with
 empty input handling

---
 src/calculator/Calculator.js | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 src/calculator/Calculator.js

diff --git a/src/calculator/Calculator.js b/src/calculator/Calculator.js
new file mode 100644
index 00000000..0235f9ec
--- /dev/null
+++ b/src/calculator/Calculator.js
@@ -0,0 +1,6 @@
+export function calculateSum(input) {
+  if (input == null) throw new Error("입력이 필요합니다.");
+  if (input === "") return 0;
+
+  return 0;
+}

From 84f1ebda0d74bda9c3f88a4f9164aebfa8dc0ac9 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:25:47 +0900
Subject: [PATCH 10/15] feat(calculator): integrate Parser to compute sum of
 parsed tokens

---
 src/calculator/Calculator.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/calculator/Calculator.js b/src/calculator/Calculator.js
index 0235f9ec..f669cbc5 100644
--- a/src/calculator/Calculator.js
+++ b/src/calculator/Calculator.js
@@ -1,6 +1,9 @@
+import Parser from "./Parser.js";
+
 export function calculateSum(input) {
   if (input == null) throw new Error("입력이 필요합니다.");
   if (input === "") return 0;
 
-  return 0;
+  const tokens = Parser.parse(input);
+  return tokens.reduce((sum, t) => sum + Number(t), 0);
 }

From 33071f8f880d8a6bd4b3c99933b348d266598986 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:27:06 +0900
Subject: [PATCH 11/15] feat(validator): add validator

---
 src/calculator/Validator.js | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 src/calculator/Validator.js

diff --git a/src/calculator/Validator.js b/src/calculator/Validator.js
new file mode 100644
index 00000000..cdf5c65a
--- /dev/null
+++ b/src/calculator/Validator.js
@@ -0,0 +1,17 @@
+export function validateTokens(tokens) {
+  if (!Array.isArray(tokens)) {
+    throw new Error("유효하지 않은 입력입니다.");
+  }
+
+  for (const t of tokens) {
+    if (t === "") throw new Error("유효하지 않은 구분자 사용입니다.");
+
+    if (!/^-?\d+$/.test(t)) throw new Error("숫자만 입력할 수 있습니다.");
+
+    const n = Number(t);
+
+    if (n < 0) throw new Error("음수는 허용되지 않습니다.");
+
+    if (n === 0) throw new Error("양수만 입력할 수 있습니다.");
+  }
+}

From 23408c1942a055e09431d8eaf227ff11a83b4fad Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:27:19 +0900
Subject: [PATCH 12/15] feat(calculator): add Validator to enforce input
 validation before summation

---
 src/calculator/Calculator.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/calculator/Calculator.js b/src/calculator/Calculator.js
index f669cbc5..18d2fd87 100644
--- a/src/calculator/Calculator.js
+++ b/src/calculator/Calculator.js
@@ -1,9 +1,14 @@
 import Parser from "./Parser.js";
+import { validateTokens } from "./Validator.js";
 
 export function calculateSum(input) {
   if (input == null) throw new Error("입력이 필요합니다.");
   if (input === "") return 0;
 
-  const tokens = Parser.parse(input);
+  const normalized = String(input).replace(/\\n/g, "\n");
+
+  const tokens = Parser.parse(normalized);
+  validateTokens(tokens);
+
   return tokens.reduce((sum, t) => sum + Number(t), 0);
 }

From d26de08483a31a7a5922bb2003f8d0fae9bc0eb3 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:28:10 +0900
Subject: [PATCH 13/15] feat(app): add calculator

---
 src/App.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/App.js b/src/App.js
index ab4dedd2..1bb02d75 100644
--- a/src/App.js
+++ b/src/App.js
@@ -1,4 +1,5 @@
 import { readInput, printResult, printError } from "./io/InputHandler.js";
+import { calculateSum } from "./calculator/Calculator.js";
 
 class App {
   async run() {

From 084a8dfbf8b30df39ee8b0965514de078bb50905 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:31:52 +0900
Subject: [PATCH 14/15] fix(io): print exact result format

---
 src/io/InputHandler.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/io/InputHandler.js b/src/io/InputHandler.js
index 815c3e90..8ef10629 100644
--- a/src/io/InputHandler.js
+++ b/src/io/InputHandler.js
@@ -6,7 +6,7 @@ export async function readInput() {
   return input;
 }
 export function printResult(result) {
-  Console.print(`결과 : <${result}>`);
+  Console.print(`결과 : ${result}`);
 }
 export function printError(err) {
   const m = err?.message ?? "알 수 없는 오류가 발생했습니다.";

From 7cfb2735ace8a93f771516c0d3ef2975e4e4a874 Mon Sep 17 00:00:00 2001
From: kwonjeong <kwonjeong9470@gmail.com>
Date: Mon, 20 Oct 2025 22:36:53 +0900
Subject: [PATCH 15/15] fix(app): simplify error handling and unify [ERROR]
 message formatting

---
 src/App.js             | 6 +++++-
 src/io/InputHandler.js | 5 ++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/App.js b/src/App.js
index 1bb02d75..eee77a1f 100644
--- a/src/App.js
+++ b/src/App.js
@@ -8,7 +8,11 @@ class App {
       const sum = calculateSum(input);
       printResult(sum);
     } catch (err) {
-      printError(err);
+      const message = `[ERROR] ${(
+        err?.message ?? "알 수 없는 오류가 발생했습니다."
+      ).replace(/^\[ERROR\]\s*/, "")}`;
+      printError(message);
+      throw new Error(message);
     }
   }
 }
diff --git a/src/io/InputHandler.js b/src/io/InputHandler.js
index 8ef10629..ee3c99c3 100644
--- a/src/io/InputHandler.js
+++ b/src/io/InputHandler.js
@@ -8,7 +8,6 @@ export async function readInput() {
 export function printResult(result) {
   Console.print(`결과 : ${result}`);
 }
-export function printError(err) {
-  const m = err?.message ?? "알 수 없는 오류가 발생했습니다.";
-  Console.print(`[ERROR] ${m}`);
+export function printError(message) {
+  Console.print(message);
 }